diff --git a/services/blob/src/database/client.rs b/services/blob/src/database/client.rs
index 160687708..7b37222f3 100644
--- a/services/blob/src/database/client.rs
+++ b/services/blob/src/database/client.rs
@@ -1,289 +1,289 @@
 use aws_sdk_dynamodb::{
   operation::put_item::PutItemOutput,
   types::{AttributeValue, Delete, TransactWriteItem, Update},
   Error as DynamoDBError,
 };
 use chrono::Utc;
-use comm_services_lib::database::parse_string_attribute;
+use comm_services_lib::database::TryFromAttribute;
 use std::{collections::HashMap, sync::Arc};
 use tracing::{debug, error, trace};
 
 use crate::constants::db::*;
 
 use super::errors::{BlobDBError, Error as DBError};
 use super::types::*;
 
 #[derive(Clone)]
 pub struct DatabaseClient {
   ddb: Arc<aws_sdk_dynamodb::Client>,
 }
 
 /// public interface implementation
 impl DatabaseClient {
   pub fn new(aws_config: &aws_types::SdkConfig) -> Self {
     DatabaseClient {
       ddb: Arc::new(aws_sdk_dynamodb::Client::new(aws_config)),
     }
   }
 
   /// Gets a blob item row from the database by its blob hash
   /// Returns None if the blob item is not found
   pub async fn get_blob_item(
     &self,
     blob_hash: impl Into<String>,
   ) -> DBResult<Option<BlobItemRow>> {
     let key = PrimaryKey::for_blob_item(blob_hash);
     self
       .get_raw_item(key.clone())
       .await?
       .map(BlobItemRow::try_from)
       .transpose()
   }
 
   /// Inserts a new blob item row into the database. Returns Error
   /// if the item already exists.
   pub async fn put_blob_item(&self, blob_item: BlobItemInput) -> DBResult<()> {
     let item = HashMap::from([
       (
         ATTR_BLOB_HASH.to_string(),
         AttributeValue::S(blob_item.blob_hash),
       ),
       (
         ATTR_HOLDER.to_string(),
         AttributeValue::S(BLOB_ITEM_ROW_HOLDER_VALUE.into()),
       ),
       (
         ATTR_S3_PATH.to_string(),
         AttributeValue::S(blob_item.s3_path.to_full_path()),
       ),
       (ATTR_UNCHECKED.to_string(), UncheckedKind::Blob.into()),
     ]);
 
     self.insert_item(item).await?;
     Ok(())
   }
 
   /// Deletes blob item row. Doesn't delete its holders.
   pub async fn delete_blob_item(
     &self,
     blob_hash: impl Into<String>,
   ) -> DBResult<()> {
     let key = PrimaryKey::for_blob_item(blob_hash);
     self
       .ddb
       .delete_item()
       .table_name(BLOB_TABLE_NAME)
       .set_key(Some(key.into()))
       .send()
       .await
       .map_err(|err| {
         debug!("DynamoDB client failed to delete blob item: {:?}", err);
         DBError::AwsSdk(err.into())
       })?;
     Ok(())
   }
 
   // Inserts a new holder assignment row into the database. Returns Error
   // if the item already exists or holder format is invalid.
   pub async fn put_holder_assignment(
     &self,
     blob_hash: impl Into<String>,
     holder: impl Into<String>,
   ) -> DBResult<()> {
     let blob_hash: String = blob_hash.into();
     let holder: String = holder.into();
 
     validate_holder(&holder)?;
     let item = HashMap::from([
       (ATTR_BLOB_HASH.to_string(), AttributeValue::S(blob_hash)),
       (ATTR_HOLDER.to_string(), AttributeValue::S(holder)),
       (ATTR_UNCHECKED.to_string(), UncheckedKind::Holder.into()),
     ]);
 
     self.insert_item(item).await?;
     Ok(())
   }
 
   /// Deletes a holder assignment row from the table.
   /// If the blob item for given holder assignment exists, it will be marked as unchecked.
   ///
   /// Returns Error if the holder format is invalid or race condition happened.
   /// Doesn't fail if the holder assignment didn't exist before.
   pub async fn delete_holder_assignment(
     &self,
     blob_hash: impl Into<String>,
     holder: impl Into<String>,
   ) -> DBResult<()> {
     let blob_hash: String = blob_hash.into();
     let holder: String = holder.into();
     validate_holder(&holder)?;
     let mut transaction = Vec::new();
 
     // delete the holder row
     let assignment_key = PrimaryKey {
       blob_hash: blob_hash.clone(),
       holder: holder.into(),
     };
     let delete_request = Delete::builder()
       .table_name(BLOB_TABLE_NAME)
       .set_key(Some(assignment_key.into()))
       .build();
     transaction
       .push(TransactWriteItem::builder().delete(delete_request).build());
 
     // mark the blob item as unchecked if exists
     let blob_primary_key = PrimaryKey::for_blob_item(blob_hash);
     if self.get_raw_item(blob_primary_key.clone()).await?.is_some() {
       let update_request = Update::builder()
         .table_name(BLOB_TABLE_NAME)
         .set_key(Some(blob_primary_key.into()))
         // even though we checked that the blob item exists, we still need to check it again
         // using DDB built-in conditions in case it was deleted in meantime
         .condition_expression(
           "attribute_exists(#blob_hash) AND attribute_exists(#holder)",
         )
         .update_expression("SET #unchecked = :unchecked, #last_modified = :now")
         .expression_attribute_names("#blob_hash", ATTR_BLOB_HASH)
         .expression_attribute_names("#holder", ATTR_HOLDER)
         .expression_attribute_names("#unchecked", ATTR_UNCHECKED)
         .expression_attribute_names("#last_modified", ATTR_LAST_MODIFIED)
         .expression_attribute_values(":unchecked", UncheckedKind::Blob.into())
         .expression_attribute_values(
           ":now",
           AttributeValue::N(Utc::now().timestamp_millis().to_string()),
         )
         .build();
       transaction
         .push(TransactWriteItem::builder().update(update_request).build());
     }
 
     self
       .ddb
       .transact_write_items()
       .set_transact_items(Some(transaction))
       .send()
       .await
       .map_err(|err| {
         debug!("DynamoDB client failed to run transaction: {:?}", err);
         DBError::AwsSdk(err.into())
       })?;
     Ok(())
   }
 
   /// Queries the table for a list of holders for given blob hash.
   /// Optionally limits the number of results.
   pub async fn list_blob_holders(
     &self,
     blob_hash: impl Into<String>,
     limit: Option<i32>,
   ) -> DBResult<Vec<String>> {
     let response = self
       .ddb
       .query()
       .table_name(BLOB_TABLE_NAME)
       .projection_expression("#holder")
       .key_condition_expression("#blob_hash = :blob_hash")
       .expression_attribute_names("#blob_hash", ATTR_BLOB_HASH)
       .expression_attribute_names("#holder", ATTR_HOLDER)
       .expression_attribute_values(
         ":blob_hash",
         AttributeValue::S(blob_hash.into()),
       )
       .consistent_read(true)
       .set_limit(limit)
       .send()
       .await
       .map_err(|err| {
         error!("DynamoDB client failed to query holders: {:?}", err);
         DBError::AwsSdk(err.into())
       })?;
 
     let Some(items) = response.items else { return Ok(vec![]); };
     items
       .into_iter()
       .filter_map(|mut row| {
         // filter out rows that are blob items
         // we cannot do it in key condition expression - it doesn't support the <> operator
         // filter expression doesn't work either - it doesn't support filtering by sort key
-        match parse_string_attribute(ATTR_HOLDER, row.remove(ATTR_HOLDER)) {
+        match String::try_from_attr(ATTR_HOLDER, row.remove(ATTR_HOLDER)) {
           Ok(value) if value.as_str() == BLOB_ITEM_ROW_HOLDER_VALUE => None,
           holder => Some(holder),
         }
       })
       .collect::<Result<Vec<_>, _>>()
       .map_err(|err| DBError::Attribute(err))
   }
 }
 
 // private helpers
 impl DatabaseClient {
   /// inserts a new item into the table using PutItem. Returns
   /// error if the item already exists
   async fn insert_item(
     &self,
     mut item: RawAttributes,
   ) -> DBResult<PutItemOutput> {
     // add metadata attributes common for all types of rows
     let now = Utc::now().timestamp_millis();
     item.insert(
       ATTR_CREATED_AT.to_string(),
       AttributeValue::N(now.to_string()),
     );
     item.insert(
       ATTR_LAST_MODIFIED.to_string(),
       AttributeValue::N(now.to_string()),
     );
 
     self
       .ddb
       .put_item()
       .table_name(BLOB_TABLE_NAME)
       .set_item(Some(item))
       // make sure we don't accidentaly overwrite existing row
       .condition_expression(
         "attribute_not_exists(#blob_hash) AND attribute_not_exists(#holder)",
       )
       .expression_attribute_names("#blob_hash", ATTR_BLOB_HASH)
       .expression_attribute_names("#holder", ATTR_HOLDER)
       .send()
       .await
       .map_err(|err| match DynamoDBError::from(err) {
         DynamoDBError::ConditionalCheckFailedException(e) => {
           debug!("DynamoDB client failed to insert: item already exists");
           trace!("Conditional check failed with error: {}", e);
           DBError::ItemAlreadyExists
         }
         err => {
           debug!("DynamoDB client failed to insert: {:?}", err);
           DBError::AwsSdk(err)
         }
       })
   }
 
   /// Gets a single row from the table using GetItem, without parsing it
   async fn get_raw_item(
     &self,
     key: PrimaryKey,
   ) -> DBResult<Option<RawAttributes>> {
     self
       .ddb
       .get_item()
       .table_name(BLOB_TABLE_NAME)
       .set_key(Some(key.into()))
       .send()
       .await
       .map_err(|err| {
         debug!("DynamoDB client failed to get item: {:?}", err);
         DBError::AwsSdk(err.into())
       })
       .map(|response| response.item)
   }
 }
 
 fn validate_holder(holder: &str) -> DBResult<()> {
   if holder == BLOB_ITEM_ROW_HOLDER_VALUE {
     debug!("Invalid holder: {}", holder);
     return Err(DBError::Blob(BlobDBError::InvalidInput(holder.to_string())));
   }
   Ok(())
 }
diff --git a/services/blob/src/database/old.rs b/services/blob/src/database/old.rs
index 4d5c743a9..452f99440 100644
--- a/services/blob/src/database/old.rs
+++ b/services/blob/src/database/old.rs
@@ -1,306 +1,308 @@
+#![allow(deprecated)]
+
 use aws_sdk_dynamodb::{
   operation::get_item::GetItemOutput, types::AttributeValue,
 };
 use chrono::{DateTime, Utc};
 use comm_services_lib::database;
 use std::{collections::HashMap, sync::Arc};
 use tracing::error;
 
 use crate::{
   config::CONFIG,
   constants::{
     BLOB_REVERSE_INDEX_TABLE_BLOB_HASH_FIELD,
     BLOB_REVERSE_INDEX_TABLE_HASH_INDEX_NAME,
     BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD, BLOB_REVERSE_INDEX_TABLE_NAME,
     BLOB_TABLE_BLOB_HASH_FIELD, BLOB_TABLE_CREATED_FIELD, BLOB_TABLE_NAME,
     BLOB_TABLE_S3_PATH_FIELD,
   },
   s3::S3Path,
 };
 
 use super::errors::{BlobDBError, Error};
 
 #[derive(Clone, Debug)]
 pub struct BlobItem {
   pub blob_hash: String,
   pub s3_path: S3Path,
   pub created: DateTime<Utc>,
 }
 
 impl BlobItem {
   pub fn new(blob_hash: impl Into<String>) -> Self {
     let hash_str = blob_hash.into();
     BlobItem {
       blob_hash: hash_str.clone(),
       s3_path: S3Path {
         bucket_name: CONFIG.s3_bucket_name.clone(),
         object_name: hash_str,
       },
       created: Utc::now(),
     }
   }
 }
 
 #[derive(Clone, Debug)]
 pub struct ReverseIndexItem {
   pub holder: String,
   pub blob_hash: String,
 }
 
 #[derive(Clone)]
 pub struct DatabaseClient {
   client: Arc<aws_sdk_dynamodb::Client>,
 }
 
 impl DatabaseClient {
   pub fn new(aws_config: &aws_types::SdkConfig) -> Self {
     DatabaseClient {
       client: Arc::new(aws_sdk_dynamodb::Client::new(aws_config)),
     }
   }
 
   // Blob item
 
   pub async fn put_blob_item(&self, blob_item: BlobItem) -> Result<(), Error> {
     let item = HashMap::from([
       (
         BLOB_TABLE_BLOB_HASH_FIELD.to_string(),
         AttributeValue::S(blob_item.blob_hash),
       ),
       (
         BLOB_TABLE_S3_PATH_FIELD.to_string(),
         AttributeValue::S(blob_item.s3_path.to_full_path()),
       ),
       (
         BLOB_TABLE_CREATED_FIELD.to_string(),
         AttributeValue::S(blob_item.created.to_rfc3339()),
       ),
     ]);
 
     self
       .client
       .put_item()
       .table_name(BLOB_TABLE_NAME)
       .set_item(Some(item))
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to put blob item");
         Error::AwsSdk(e.into())
       })?;
 
     Ok(())
   }
 
   pub async fn find_blob_item(
     &self,
     blob_hash: &str,
   ) -> Result<Option<BlobItem>, Error> {
     let item_key = HashMap::from([(
       BLOB_TABLE_BLOB_HASH_FIELD.to_string(),
       AttributeValue::S(blob_hash.to_string()),
     )]);
     match self
       .client
       .get_item()
       .table_name(BLOB_TABLE_NAME)
       .set_key(Some(item_key))
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to find blob item");
         Error::AwsSdk(e.into())
       })? {
       GetItemOutput {
         item: Some(mut item),
         ..
       } => {
         let blob_hash = database::parse_string_attribute(
           BLOB_TABLE_BLOB_HASH_FIELD,
           item.remove(BLOB_TABLE_BLOB_HASH_FIELD),
         )?;
         let s3_path = database::parse_string_attribute(
           BLOB_TABLE_S3_PATH_FIELD,
           item.remove(BLOB_TABLE_S3_PATH_FIELD),
         )?;
         let created = database::parse_datetime_attribute(
           BLOB_TABLE_CREATED_FIELD,
           item.remove(BLOB_TABLE_CREATED_FIELD),
         )?;
         Ok(Some(BlobItem {
           blob_hash,
           s3_path: S3Path::from_full_path(&s3_path)
             .map_err(|e| Error::Blob(BlobDBError::InvalidS3Path(e)))?,
           created,
         }))
       }
       _ => Ok(None),
     }
   }
 
   pub async fn remove_blob_item(&self, blob_hash: &str) -> Result<(), Error> {
     self
       .client
       .delete_item()
       .table_name(BLOB_TABLE_NAME)
       .key(
         BLOB_TABLE_BLOB_HASH_FIELD,
         AttributeValue::S(blob_hash.to_string()),
       )
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to remove blob item");
         Error::AwsSdk(e.into())
       })?;
 
     Ok(())
   }
 
   // Reverse index item
 
   pub async fn put_reverse_index_item(
     &self,
     reverse_index_item: ReverseIndexItem,
   ) -> Result<(), Error> {
     let holder = &reverse_index_item.holder;
     if self.find_reverse_index_by_holder(holder).await?.is_some() {
       error!("Failed to put reverse index. Holder already exists.");
       return Err(Error::Blob(BlobDBError::HolderAlreadyExists(
         holder.to_string(),
       )));
     }
 
     let item = HashMap::from([
       (
         BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD.to_string(),
         AttributeValue::S(reverse_index_item.holder),
       ),
       (
         BLOB_REVERSE_INDEX_TABLE_BLOB_HASH_FIELD.to_string(),
         AttributeValue::S(reverse_index_item.blob_hash),
       ),
     ]);
     self
       .client
       .put_item()
       .table_name(BLOB_REVERSE_INDEX_TABLE_NAME)
       .set_item(Some(item))
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to put reverse index");
         Error::AwsSdk(e.into())
       })?;
 
     Ok(())
   }
 
   pub async fn find_reverse_index_by_holder(
     &self,
     holder: &str,
   ) -> Result<Option<ReverseIndexItem>, Error> {
     let item_key = HashMap::from([(
       BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD.to_string(),
       AttributeValue::S(holder.to_string()),
     )]);
     match self
       .client
       .get_item()
       .table_name(BLOB_REVERSE_INDEX_TABLE_NAME)
       .set_key(Some(item_key))
       .consistent_read(true)
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to find reverse index by holder");
         Error::AwsSdk(e.into())
       })? {
       GetItemOutput {
         item: Some(mut item),
         ..
       } => {
         let holder = database::parse_string_attribute(
           BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD,
           item.remove(BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD),
         )?;
         let blob_hash = database::parse_string_attribute(
           BLOB_REVERSE_INDEX_TABLE_BLOB_HASH_FIELD,
           item.remove(BLOB_REVERSE_INDEX_TABLE_BLOB_HASH_FIELD),
         )?;
 
         Ok(Some(ReverseIndexItem { holder, blob_hash }))
       }
       _ => Ok(None),
     }
   }
 
   pub async fn find_reverse_index_by_hash(
     &self,
     blob_hash: &str,
   ) -> Result<Vec<ReverseIndexItem>, Error> {
     let response = self
       .client
       .query()
       .table_name(BLOB_REVERSE_INDEX_TABLE_NAME)
       .index_name(BLOB_REVERSE_INDEX_TABLE_HASH_INDEX_NAME)
       .key_condition_expression("#blobHash = :valueToMatch")
       .expression_attribute_names(
         "#blobHash",
         BLOB_REVERSE_INDEX_TABLE_BLOB_HASH_FIELD,
       )
       .expression_attribute_values(
         ":valueToMatch",
         AttributeValue::S(blob_hash.to_string()),
       )
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to find reverse indexes by hash");
         Error::AwsSdk(e.into())
       })?;
 
     if response.count == 0 {
       return Ok(vec![]);
     }
 
     let mut results: Vec<ReverseIndexItem> =
       Vec::with_capacity(response.count() as usize);
     for mut item in response.items.unwrap_or_default() {
       let holder = database::parse_string_attribute(
         BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD,
         item.remove(BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD),
       )?;
       let blob_hash = database::parse_string_attribute(
         BLOB_REVERSE_INDEX_TABLE_BLOB_HASH_FIELD,
         item.remove(BLOB_REVERSE_INDEX_TABLE_BLOB_HASH_FIELD),
       )?;
 
       results.push(ReverseIndexItem { holder, blob_hash });
     }
 
     return Ok(results);
   }
 
   pub async fn remove_reverse_index_item(
     &self,
     holder: &str,
   ) -> Result<(), Error> {
     self
       .client
       .delete_item()
       .table_name(BLOB_REVERSE_INDEX_TABLE_NAME)
       .key(
         BLOB_REVERSE_INDEX_TABLE_HOLDER_FIELD,
         AttributeValue::S(holder.to_string()),
       )
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to remove reverse index");
         Error::AwsSdk(e.into())
       })?;
 
     Ok(())
   }
 }
diff --git a/services/blob/src/database/types.rs b/services/blob/src/database/types.rs
index 5639b5786..501132313 100644
--- a/services/blob/src/database/types.rs
+++ b/services/blob/src/database/types.rs
@@ -1,241 +1,237 @@
 use aws_sdk_dynamodb::types::AttributeValue;
 use chrono::{DateTime, Utc};
 use comm_services_lib::database::{
-  parse_string_attribute, parse_timestamp_attribute, DBItemError, Value,
+  parse_timestamp_attribute, AttributeTryInto, DBItemError, Value,
 };
 use derive_more::Constructor;
 use std::collections::HashMap;
 
 use crate::{config::CONFIG, constants::db::*, s3::S3Path};
 
 use super::errors::Error as DBError;
 
 /// Represents a database row in the DynamoDB SDK format
 pub(super) type RawAttributes = HashMap<String, AttributeValue>;
 /// A convenience Result type for database operations
 pub(super) type DBResult<T> = Result<T, DBError>;
 
 /// Represents a type-safe version of a DynamoDB blob table item.
 /// Each row can be either a blob item or a holder assignment.
 ///
 /// It implements the `TryFrom` trait to convert from raw DynamoDB
 /// `AttributeValue`s to the type-safe version.
 pub enum DBRow {
   BlobItem(BlobItemRow),
   HolderAssignment(HolderAssignmentRow),
 }
 
 impl TryFrom<RawAttributes> for DBRow {
   type Error = DBError;
 
   fn try_from(attributes: RawAttributes) -> Result<Self, Self::Error> {
-    let holder = parse_string_attribute(
-      ATTR_HOLDER,
-      attributes.get(ATTR_HOLDER).cloned(),
-    )?;
+    let holder: String = attributes
+      .get(ATTR_HOLDER)
+      .cloned()
+      .attr_try_into(ATTR_HOLDER)?;
     let row = match holder.as_str() {
       BLOB_ITEM_ROW_HOLDER_VALUE => DBRow::BlobItem(attributes.try_into()?),
       _ => DBRow::HolderAssignment(attributes.try_into()?),
     };
     Ok(row)
   }
 }
 
 /// Represents an input payload for inserting a blob item into the database.
 /// This contains only the business logic related attributes
 #[derive(Debug)]
 pub struct BlobItemInput {
   pub blob_hash: String,
   pub s3_path: S3Path,
 }
 
 impl BlobItemInput {
   pub fn new(blob_hash: impl Into<String>) -> Self {
     let blob_hash: String = blob_hash.into();
     BlobItemInput {
       blob_hash: blob_hash.clone(),
       s3_path: S3Path {
         bucket_name: CONFIG.s3_bucket_name.clone(),
         object_name: blob_hash,
       },
     }
   }
 }
 
 /// A struct representing a blob item row in the table in a type-safe way
 ///
 /// It implements the `TryFrom` trait to convert from raw DynamoDB
 /// `AttributeValue`s to the type-safe version.
 #[derive(Debug)]
 pub struct BlobItemRow {
   pub blob_hash: String,
   pub s3_path: S3Path,
   pub unchecked: bool,
   pub created_at: DateTime<Utc>,
   pub last_modified: DateTime<Utc>,
 }
 
 impl TryFrom<RawAttributes> for BlobItemRow {
   type Error = DBError;
 
   fn try_from(mut attributes: RawAttributes) -> Result<Self, Self::Error> {
-    let blob_hash = parse_string_attribute(
-      ATTR_BLOB_HASH,
-      attributes.remove(ATTR_BLOB_HASH),
-    )?;
-    let s3_path =
-      parse_string_attribute(ATTR_S3_PATH, attributes.remove(ATTR_S3_PATH))?;
+    let blob_hash = attributes
+      .remove(ATTR_BLOB_HASH)
+      .attr_try_into(ATTR_BLOB_HASH)?;
+    let s3_path: String = attributes
+      .remove(ATTR_S3_PATH)
+      .attr_try_into(ATTR_S3_PATH)?;
     let created_at = parse_timestamp_attribute(
       ATTR_CREATED_AT,
       attributes.remove(ATTR_CREATED_AT),
     )?;
     let last_modified = parse_timestamp_attribute(
       ATTR_LAST_MODIFIED,
       attributes.remove(ATTR_LAST_MODIFIED),
     )?;
     let unchecked = is_raw_row_unchecked(&attributes, UncheckedKind::Blob)?;
     let s3_path = S3Path::from_full_path(&s3_path).map_err(DBError::from)?;
 
     Ok(BlobItemRow {
       blob_hash,
       s3_path,
       unchecked,
       created_at,
       last_modified,
     })
   }
 }
 
 /// A struct representing a holder assignment table row in a type-safe way
 ///
 /// It implements the `TryFrom` trait to convert from raw DynamoDB
 /// `AttributeValue`s to the type-safe version.
 #[derive(Debug)]
 pub struct HolderAssignmentRow {
   pub blob_hash: String,
   pub holder: String,
   pub unchecked: bool,
   pub created_at: DateTime<Utc>,
   pub last_modified: DateTime<Utc>,
 }
 
 impl TryFrom<RawAttributes> for HolderAssignmentRow {
   type Error = DBError;
 
   fn try_from(mut attributes: RawAttributes) -> Result<Self, Self::Error> {
-    let holder =
-      parse_string_attribute(ATTR_HOLDER, attributes.remove(ATTR_HOLDER))?;
-    let blob_hash = parse_string_attribute(
-      ATTR_BLOB_HASH,
-      attributes.remove(ATTR_BLOB_HASH),
-    )?;
+    let holder = attributes.remove(ATTR_HOLDER).attr_try_into(ATTR_HOLDER)?;
+    let blob_hash = attributes
+      .remove(ATTR_BLOB_HASH)
+      .attr_try_into(ATTR_BLOB_HASH)?;
     let created_at = parse_timestamp_attribute(
       ATTR_CREATED_AT,
       attributes.remove(ATTR_CREATED_AT),
     )?;
     let last_modified = parse_timestamp_attribute(
       ATTR_LAST_MODIFIED,
       attributes.remove(ATTR_LAST_MODIFIED),
     )?;
     let unchecked = is_raw_row_unchecked(&attributes, UncheckedKind::Holder)?;
     Ok(HolderAssignmentRow {
       blob_hash,
       holder,
       unchecked,
       created_at,
       last_modified,
     })
   }
 }
 
 /// Represents a composite primary key for a DynamoDB table row
 ///
 /// It implements `TryFrom` and `Into` traits to conveniently use it
 /// in DynamoDB queries
 #[derive(Clone, Constructor, Debug)]
 pub struct PrimaryKey {
   pub blob_hash: String,
   pub holder: String,
 }
 
 impl PrimaryKey {
   /// Creates a primary key for a row containing a blob item data
   /// Rows queried by primary keys created by this function will
   /// be of type `BlobItemRow`
   pub fn for_blob_item(blob_hash: impl Into<String>) -> Self {
     PrimaryKey {
       blob_hash: blob_hash.into(),
       holder: BLOB_ITEM_ROW_HOLDER_VALUE.to_string(),
     }
   }
 }
 
 impl TryFrom<RawAttributes> for PrimaryKey {
   type Error = DBError;
 
   fn try_from(mut attributes: RawAttributes) -> Result<Self, Self::Error> {
-    let blob_hash = parse_string_attribute(
-      ATTR_BLOB_HASH,
-      attributes.remove(ATTR_BLOB_HASH),
-    )?;
-    let holder =
-      parse_string_attribute(ATTR_HOLDER, attributes.remove(ATTR_HOLDER))?;
+    let blob_hash = attributes
+      .remove(ATTR_BLOB_HASH)
+      .attr_try_into(ATTR_BLOB_HASH)?;
+    let holder = attributes.remove(ATTR_HOLDER).attr_try_into(ATTR_HOLDER)?;
     Ok(PrimaryKey { blob_hash, holder })
   }
 }
 
 // useful for convenient calls:
 // ddb.get_item().set_key(Some(partition_key.into()))
 impl Into<RawAttributes> for PrimaryKey {
   fn into(self) -> RawAttributes {
     HashMap::from([
       (
         ATTR_BLOB_HASH.to_string(),
         AttributeValue::S(self.blob_hash),
       ),
       (ATTR_HOLDER.to_string(), AttributeValue::S(self.holder)),
     ])
   }
 }
 
 /// Represents possible values for the `unchecked` attribute value
 pub enum UncheckedKind {
   Blob,
   Holder,
 }
 
 impl UncheckedKind {
   pub fn str_value(&self) -> &'static str {
     match self {
       UncheckedKind::Blob => "blob",
       UncheckedKind::Holder => "holder",
     }
   }
 }
 
 impl Into<AttributeValue> for UncheckedKind {
   fn into(self) -> AttributeValue {
     AttributeValue::S(self.str_value().to_string())
   }
 }
 
 fn is_raw_row_unchecked(
   row: &RawAttributes,
   kind: UncheckedKind,
 ) -> DBResult<bool> {
   let Some(AttributeValue::S(value)) = row.get(ATTR_UNCHECKED) else {
     // The unchecked attribute not exists
     return Ok(false);
   };
 
   if value != kind.str_value() {
     // The unchecked attribute exists but has an incorrect value
     return Err(DBError::Attribute(DBItemError::new(
       ATTR_UNCHECKED.to_string(),
       Value::String(value.to_string()),
       comm_services_lib::database::DBItemAttributeError::IncorrectType,
     )));
   }
 
   Ok(true)
 }
diff --git a/services/blob/src/service.rs b/services/blob/src/service.rs
index c9f8bc1f7..26de0a746 100644
--- a/services/blob/src/service.rs
+++ b/services/blob/src/service.rs
@@ -1,286 +1,286 @@
 #![allow(unused)]
 use std::ops::{Bound, Range, RangeBounds, RangeInclusive};
 use std::sync::Arc;
 
 use async_stream::try_stream;
 use chrono::Duration;
 use tokio_stream::StreamExt;
 use tonic::codegen::futures_core::Stream;
 use tracing::{debug, error, trace, warn};
 
 use crate::constants::S3_MULTIPART_UPLOAD_MINIMUM_CHUNK_SIZE;
 use crate::database::types::{
   BlobItemInput, BlobItemRow, PrimaryKey, UncheckedKind,
 };
 use crate::database::DBError;
 use crate::s3::{Error as S3Error, S3Client, S3Path};
 use crate::tools::{BoxedError, ByteStream, MemOps};
 use crate::{constants::BLOB_DOWNLOAD_CHUNK_SIZE, database::DatabaseClient};
 
 #[derive(
   Debug, derive_more::Display, derive_more::From, derive_more::Error,
 )]
 pub enum BlobServiceError {
   BlobNotFound,
   BlobAlreadyExists,
   InvalidState,
   DB(DBError),
   S3(S3Error),
   InputError(#[error(ignore)] BoxedError),
 }
 
 type BlobServiceResult<T> = Result<T, BlobServiceError>;
 
 #[derive(Clone, Debug)]
 pub struct BlobServiceConfig {
   /// Blob data is streamed from S3 in chunks of this size.
   pub download_chunk_size: usize,
   /// If enabled, orphaned blobs will be deleted immediately after
   /// last holder is removed. This option should be enabled
   /// if maintenance garbage collection tasks are not run.
   pub instant_delete_orphaned_blobs: bool,
   /// Minimum age that a orphan must stay unmodified
   /// before it can be deleted by a garbage collection task
   /// This option is ignored if `instant_delete_orphaned_blobs` is `true`
   pub orphan_protection_period: chrono::Duration,
 }
 
 impl Default for BlobServiceConfig {
   fn default() -> Self {
     BlobServiceConfig {
       download_chunk_size: BLOB_DOWNLOAD_CHUNK_SIZE as usize,
       instant_delete_orphaned_blobs: false,
       orphan_protection_period: Duration::hours(1),
     }
   }
 }
 
 #[derive(Clone)]
 pub struct BlobService {
   db: Arc<DatabaseClient>,
   s3: S3Client,
   config: BlobServiceConfig,
 }
 
 impl BlobService {
   pub fn new(
     db: DatabaseClient,
     s3: S3Client,
     config: BlobServiceConfig,
   ) -> Self {
     Self {
       db: Arc::new(db),
       s3,
       config,
     }
   }
 
   /// Retrieves blob object metadata and returns a download object
   /// that can be used to download the blob data.
   pub async fn create_download(
     &self,
     blob_hash: impl Into<String>,
   ) -> BlobServiceResult<BlobDownloadObject> {
     // 1. Get S3 path
     let s3_path = match self.db.get_blob_item(blob_hash.into()).await {
       Ok(Some(BlobItemRow { s3_path, .. })) => Ok(s3_path),
       Ok(None) => {
         debug!("Blob not found");
         Err(BlobServiceError::BlobNotFound)
       }
       Err(err) => Err(BlobServiceError::DB(err)),
     }?;
     debug!("S3 path: {:?}", s3_path);
 
     // 2. Get S3 Object metadata
     trace!("Getting S3 object metadata...");
     let object_metadata = self.s3.get_object_metadata(&s3_path).await?;
     let blob_size: u64 =
       object_metadata.content_length().try_into().map_err(|err| {
         error!("Failed to parse S3 object content length: {:?}", err);
         BlobServiceError::InvalidState
       })?;
     debug!("S3 object size: {} bytes", blob_size);
 
     // 3. Create download session
     let session = BlobDownloadObject {
       s3_path,
       blob_size,
       byte_range: 0..blob_size,
       chunk_size: self.config.download_chunk_size as u64,
       s3_client: self.s3.clone(),
     };
     Ok(session)
   }
 
   pub async fn put_blob(
     &self,
     blob_hash: impl Into<String>,
     mut blob_data_stream: impl ByteStream,
   ) -> Result<(), BlobServiceError> {
     let blob_hash: String = blob_hash.into();
     let blob_item = BlobItemInput::new(&blob_hash);
 
     if self.db.get_blob_item(blob_hash).await?.is_some() {
       debug!("Blob already exists");
       return Err(BlobServiceError::BlobAlreadyExists);
     }
 
     let mut upload_session =
       self.s3.start_upload_session(&blob_item.s3_path).await?;
     trace!(?blob_item, "Started S3 upload session");
 
     tokio::pin!(blob_data_stream);
     let mut s3_chunk: Vec<u8> = Vec::new();
     while let Some(mut chunk) =
       blob_data_stream.try_next().await.map_err(|err| {
         warn!("Failed to get data chunk: {:?}", err);
         BlobServiceError::InputError(err)
       })?
     {
       s3_chunk.append(&mut chunk);
 
       // New parts should be added to AWS only if they exceed minimum part size,
       // Otherwise AWS returns error
       if s3_chunk.len() as u64 > S3_MULTIPART_UPLOAD_MINIMUM_CHUNK_SIZE {
         trace!(
           chunk_size = s3_chunk.len(),
           "Chunk size exceeded, adding new S3 part"
         );
         upload_session
           .add_part(s3_chunk.take_out())
           .await
           .map_err(BlobServiceError::from)?;
       }
     }
     trace!("Upload stream drained");
     // add the remaining data as the last S3 part
     if !s3_chunk.is_empty() {
       trace!("Uploading remaining {} bytes", s3_chunk.len());
       upload_session.add_part(s3_chunk).await?;
     }
     // Complete the upload session
     upload_session.finish_upload().await?;
 
     trace!("S3 upload complete, putting item to db");
     self.db.put_blob_item(blob_item).await?;
     Ok(())
   }
 
   pub async fn assign_holder(
     &self,
     blob_hash: impl Into<String>,
     holder: impl Into<String>,
   ) -> BlobServiceResult<bool> {
     let blob_hash: String = blob_hash.into();
     trace!(blob_hash, "Attempting to assign holder");
     self
       .db
       .put_holder_assignment(blob_hash.clone(), holder.into())
       .await?;
 
     trace!("Holder assigned. Checking if data exists");
     let data_exists = self.db.get_blob_item(blob_hash).await?.is_some();
     Ok(data_exists)
   }
 
   pub async fn revoke_holder(
     &self,
     blob_hash: impl Into<String>,
     holder: impl Into<String>,
   ) -> BlobServiceResult<()> {
     let blob_hash: String = blob_hash.into();
     let holder: String = holder.into();
 
     trace!(blob_hash, holder, "Attempting to revoke holder");
     self.db.delete_holder_assignment(&blob_hash, holder).await?;
 
     if self.config.instant_delete_orphaned_blobs {
       trace!("Instant orphan deletion enabled. Looking for holders");
       let is_orphan = self
         .db
         .list_blob_holders(&blob_hash, Some(1))
         .await?
         .is_empty();
       if !is_orphan {
         trace!("Found holders, nothing to do");
         return Ok(());
       }
 
       debug!("No holders left, deleting blob if exists");
       trace!("Getting blob item");
       let Some(blob_item) = self.db.get_blob_item(&blob_hash).await? else {
         trace!("Blob item not found, nothing to do");
-        return Ok(())
+        return Ok(());
       };
 
       trace!("Deleting S3 object");
       self.s3.delete_object(&blob_item.s3_path).await?;
       trace!("Deleting blob item entry from DB");
       self.db.delete_blob_item(blob_hash).await?;
     }
     Ok(())
   }
 }
 
 pub struct BlobDownloadObject {
   /// Size of the whole blob object in bytes.
   pub blob_size: u64,
   /// Range of bytes to be downloaded (exclusive end).
   byte_range: Range<u64>,
   chunk_size: u64,
   s3_client: S3Client,
   s3_path: S3Path,
 }
 
 impl BlobDownloadObject {
   pub fn set_byte_range(&mut self, range: impl RangeBounds<u64>) {
     let range_start = match range.start_bound() {
       Bound::Included(&start) => start,
       Bound::Excluded(&start) => start + 1,
       Bound::Unbounded => 0,
     };
     let range_end = match range.end_bound() {
       Bound::Included(&end) => end + 1,
       Bound::Excluded(&end) => end,
       Bound::Unbounded => self.blob_size,
     };
     // Clamp range to blob size
     let start = std::cmp::max(range_start, 0);
     let end_exclusive = std::cmp::min(range_end, self.blob_size);
 
     self.byte_range = start..end_exclusive;
     debug!("Requested byte range: {}..{}", start, end_exclusive);
   }
 
   /// Size of the data to be downloaded in bytes.
   pub fn download_size(&self) -> u64 {
     self.byte_range.end - self.byte_range.start
   }
 
   pub fn into_stream(self) -> impl Stream<Item = BlobServiceResult<Vec<u8>>> {
     let BlobDownloadObject {
       byte_range,
       chunk_size,
       s3_path,
       s3_client,
       ..
     } = self;
 
     try_stream! {
       trace!("Starting download stream");
       let mut offset: u64 = byte_range.start;
       while offset < byte_range.end {
         let next_size = std::cmp::min(chunk_size, byte_range.end - offset);
         let range = offset..(offset + next_size);
         trace!(?range, "Getting {} bytes of data", next_size);
 
         yield s3_client
           .get_object_bytes(&s3_path, range)
           .await?;
 
         offset += next_size;
       }
     }
   }
 }
diff --git a/services/comm-services-lib/src/database.rs b/services/comm-services-lib/src/database.rs
index d12180445..85aeccabe 100644
--- a/services/comm-services-lib/src/database.rs
+++ b/services/comm-services-lib/src/database.rs
@@ -1,350 +1,366 @@
 use aws_sdk_dynamodb::types::AttributeValue;
 use aws_sdk_dynamodb::Error as DynamoDBError;
 use chrono::{DateTime, Utc};
-use std::collections::HashMap;
 use std::fmt::{Display, Formatter};
 use std::num::ParseIntError;
 use std::str::FromStr;
 
+// # Useful type aliases
+
+// Rust exports `pub type` only into the so-called "type namespace", but in
+// order to use them e.g. with the `TryFromAttribute` trait, they also need
+// to be exported into the "value namespace" which is what `pub use` does.
+//
+// To overcome that, a dummy module is created and aliases are re-exported
+// with `pub use` construct
+mod aliases {
+  use aws_sdk_dynamodb::types::AttributeValue;
+  use std::collections::HashMap;
+  pub type AttributeMap = HashMap<String, AttributeValue>;
+}
+pub use self::aliases::AttributeMap;
+
+// # Error handling
+
 #[derive(
   Debug, derive_more::Display, derive_more::From, derive_more::Error,
 )]
 pub enum Error {
   #[display(...)]
   AwsSdk(DynamoDBError),
   #[display(...)]
   Attribute(DBItemError),
 }
 
 #[derive(Debug)]
 pub enum Value {
   AttributeValue(Option<AttributeValue>),
   String(String),
 }
 
 #[derive(Debug, derive_more::Error, derive_more::Constructor)]
 pub struct DBItemError {
   attribute_name: String,
   attribute_value: Value,
   attribute_error: DBItemAttributeError,
 }
 
 impl Display for DBItemError {
   fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
     match &self.attribute_error {
       DBItemAttributeError::Missing => {
         write!(f, "Attribute {} is missing", self.attribute_name)
       }
       DBItemAttributeError::IncorrectType => write!(
         f,
         "Value for attribute {} has incorrect type: {:?}",
         self.attribute_name, self.attribute_value
       ),
       error => write!(
         f,
         "Error regarding attribute {} with value {:?}: {}",
         self.attribute_name, self.attribute_value, error
       ),
     }
   }
 }
 
 #[derive(Debug, derive_more::Display, derive_more::Error)]
 pub enum DBItemAttributeError {
   #[display(...)]
   Missing,
   #[display(...)]
   IncorrectType,
   #[display(...)]
   TimestampOutOfRange,
   #[display(...)]
   InvalidTimestamp(chrono::ParseError),
   #[display(...)]
   InvalidNumberFormat(ParseIntError),
 }
 
 /// Conversion trait for [`AttributeValue`]
 ///
 /// Types implementing this trait are able to do the following:
 /// ```rust
 /// use comm_services_lib::database::{TryFromAttribute, AttributeTryInto};
 ///
 /// let foo = SomeType::try_from_attr("MyAttribute", Some(attribute));
 ///
 /// // if `AttributeTryInto` is imported, also:
 /// let bar = Some(attribute).attr_try_into("MyAttribute");
 pub trait TryFromAttribute: Sized {
   fn try_from_attr(
     attribute_name: impl Into<String>,
     attribute: Option<AttributeValue>,
   ) -> Result<Self, DBItemError>;
 }
 
 /// Do NOT implement this trait directly. Implement [`TryFromAttribute`] instead
 pub trait AttributeTryInto<T> {
   fn attr_try_into(
     self,
     attribute_name: impl Into<String>,
   ) -> Result<T, DBItemError>;
 }
 // Automatic attr_try_into() for all attribute values
 // that have TryFromAttribute implemented
 impl<T: TryFromAttribute> AttributeTryInto<T> for Option<AttributeValue> {
   fn attr_try_into(
     self,
     attribute_name: impl Into<String>,
   ) -> Result<T, DBItemError> {
     T::try_from_attr(attribute_name, self)
   }
 }
 
 impl TryFromAttribute for String {
   fn try_from_attr(
     attribute_name: impl Into<String>,
     attribute_value: Option<AttributeValue>,
   ) -> Result<Self, DBItemError> {
     match attribute_value {
       Some(AttributeValue::S(value)) => Ok(value),
       Some(_) => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::IncorrectType,
       )),
       None => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::Missing,
       )),
     }
   }
 }
 
 impl TryFromAttribute for bool {
   fn try_from_attr(
     attribute_name: impl Into<String>,
     attribute_value: Option<AttributeValue>,
   ) -> Result<Self, DBItemError> {
     match attribute_value {
       Some(AttributeValue::Bool(value)) => Ok(value),
       Some(_) => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::IncorrectType,
       )),
       None => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::Missing,
       )),
     }
   }
 }
 
 impl TryFromAttribute for DateTime<Utc> {
   fn try_from_attr(
     attribute_name: impl Into<String>,
     attribute: Option<AttributeValue>,
   ) -> Result<Self, DBItemError> {
     match &attribute {
       Some(AttributeValue::S(datetime)) => datetime.parse().map_err(|e| {
         DBItemError::new(
           attribute_name.into(),
           Value::AttributeValue(attribute),
           DBItemAttributeError::InvalidTimestamp(e),
         )
       }),
       Some(_) => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute),
         DBItemAttributeError::IncorrectType,
       )),
       None => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute),
         DBItemAttributeError::Missing,
       )),
     }
   }
 }
 
-impl TryFromAttribute for HashMap<String, AttributeValue> {
+impl TryFromAttribute for AttributeMap {
   fn try_from_attr(
     attribute_name: impl Into<String>,
     attribute_value: Option<AttributeValue>,
   ) -> Result<Self, DBItemError> {
     match attribute_value {
       Some(AttributeValue::M(map)) => Ok(map),
       Some(_) => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::IncorrectType,
       )),
       None => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::Missing,
       )),
     }
   }
 }
 
 impl TryFromAttribute for Vec<u8> {
   fn try_from_attr(
     attribute_name: impl Into<String>,
     attribute_value: Option<AttributeValue>,
   ) -> Result<Self, DBItemError> {
     match attribute_value {
       Some(AttributeValue::B(data)) => Ok(data.into_inner()),
       Some(_) => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::IncorrectType,
       )),
       None => Err(DBItemError::new(
         attribute_name.into(),
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::Missing,
       )),
     }
   }
 }
 
 #[deprecated = "Use `String::try_from_attr()` instead"]
 pub fn parse_string_attribute(
   attribute_name: impl Into<String>,
   attribute_value: Option<AttributeValue>,
 ) -> Result<String, DBItemError> {
   String::try_from_attr(attribute_name, attribute_value)
 }
 
 #[deprecated = "Use `bool::try_from_attr()` instead"]
 pub fn parse_bool_attribute(
   attribute_name: impl Into<String>,
   attribute_value: Option<AttributeValue>,
 ) -> Result<bool, DBItemError> {
   bool::try_from_attr(attribute_name, attribute_value)
 }
 
 #[deprecated = "Use `DateTime::<Utc>::try_from_attr()` instead"]
 pub fn parse_datetime_attribute(
   attribute_name: impl Into<String>,
   attribute_value: Option<AttributeValue>,
 ) -> Result<DateTime<Utc>, DBItemError> {
   DateTime::<Utc>::try_from_attr(attribute_name, attribute_value)
 }
 
-#[deprecated = "Use `HashMap::<String, AttributeValue>::try_from_attr()` instead"]
+#[deprecated = "Use `AttributeMap::try_from_attr()` instead"]
 pub fn parse_map_attribute(
   attribute_name: impl Into<String>,
   attribute_value: Option<AttributeValue>,
-) -> Result<HashMap<String, AttributeValue>, DBItemError> {
+) -> Result<AttributeMap, DBItemError> {
   attribute_value.attr_try_into(attribute_name)
 }
 
 pub fn parse_int_attribute<T>(
   attribute_name: impl Into<String>,
   attribute_value: Option<AttributeValue>,
 ) -> Result<T, DBItemError>
 where
   T: FromStr<Err = ParseIntError>,
 {
   match &attribute_value {
     Some(AttributeValue::N(numeric_str)) => {
       parse_integer(attribute_name, numeric_str)
     }
     Some(_) => Err(DBItemError::new(
       attribute_name.into(),
       Value::AttributeValue(attribute_value),
       DBItemAttributeError::IncorrectType,
     )),
     None => Err(DBItemError::new(
       attribute_name.into(),
       Value::AttributeValue(attribute_value),
       DBItemAttributeError::Missing,
     )),
   }
 }
 
 /// Parses the UTC timestamp in milliseconds from a DynamoDB numeric attribute
 pub fn parse_timestamp_attribute(
   attribute_name: impl Into<String>,
   attribute_value: Option<AttributeValue>,
 ) -> Result<DateTime<Utc>, DBItemError> {
   let attribute_name: String = attribute_name.into();
   let timestamp = parse_int_attribute::<i64>(
     attribute_name.clone(),
     attribute_value.clone(),
   )?;
   let naive_datetime = chrono::NaiveDateTime::from_timestamp_millis(timestamp)
     .ok_or_else(|| {
       DBItemError::new(
         attribute_name,
         Value::AttributeValue(attribute_value),
         DBItemAttributeError::TimestampOutOfRange,
       )
     })?;
   Ok(DateTime::from_utc(naive_datetime, Utc))
 }
 
 pub fn parse_integer<T>(
   attribute_name: impl Into<String>,
   attribute_value: &str,
 ) -> Result<T, DBItemError>
 where
   T: FromStr<Err = ParseIntError>,
 {
   attribute_value.parse::<T>().map_err(|e| {
     DBItemError::new(
       attribute_name.into(),
       Value::String(attribute_value.into()),
       DBItemAttributeError::InvalidNumberFormat(e),
     )
   })
 }
 
 #[cfg(test)]
 
 mod tests {
   use super::*;
 
   #[test]
   fn test_parse_integer() {
     assert!(parse_integer::<i32>("some_attr", "123").is_ok());
     assert!(parse_integer::<i32>("negative", "-123").is_ok());
 
     assert!(parse_integer::<i32>("float", "3.14").is_err());
     assert!(parse_integer::<i32>("NaN", "foo").is_err());
 
     assert!(parse_integer::<u32>("negative_uint", "-123").is_err());
     assert!(parse_integer::<u8>("too_large", "65536").is_err());
   }
 
   #[test]
   fn test_parse_timestamp() {
     let timestamp = Utc::now().timestamp_millis();
     let attr = AttributeValue::N(timestamp.to_string());
 
     let parsed_timestamp = parse_timestamp_attribute("some_attr", Some(attr));
 
     assert!(parsed_timestamp.is_ok());
     assert_eq!(parsed_timestamp.unwrap().timestamp_millis(), timestamp);
   }
 
   #[test]
   fn test_parse_invalid_timestamp() {
     let attr = AttributeValue::N("foo".to_string());
     let parsed_timestamp = parse_timestamp_attribute("some_attr", Some(attr));
     assert!(parsed_timestamp.is_err());
   }
 
   #[test]
   fn test_parse_timestamp_out_of_range() {
     let attr = AttributeValue::N(i64::MAX.to_string());
     let parsed_timestamp = parse_timestamp_attribute("some_attr", Some(attr));
     assert!(parsed_timestamp.is_err());
     assert!(matches!(
       parsed_timestamp.unwrap_err().attribute_error,
       DBItemAttributeError::TimestampOutOfRange
     ));
   }
 }
diff --git a/services/feature-flags/src/database.rs b/services/feature-flags/src/database.rs
index 5b73bd3db..b033c2fe1 100644
--- a/services/feature-flags/src/database.rs
+++ b/services/feature-flags/src/database.rs
@@ -1,120 +1,122 @@
 use crate::constants::{
   FEATURE_FLAGS_CONFIG_FIELD, FEATURE_FLAGS_FEATURE_FIELD,
   FEATURE_FLAGS_NON_STAFF_FIELD, FEATURE_FLAGS_PLATFORM_FIELD,
   FEATURE_FLAGS_STAFF_FIELD, FEATURE_FLAGS_TABLE_NAME, PLATFORM_ANDROID,
   PLATFORM_IOS,
 };
 use aws_sdk_dynamodb::types::{AttributeValue, Select};
-use comm_services_lib::database::{self, DBItemError, Error};
+use comm_services_lib::database::{
+  self, AttributeMap, DBItemError, Error, TryFromAttribute,
+};
 use std::collections::HashMap;
 use std::sync::Arc;
 use tracing::error;
 
 #[derive(Debug)]
 pub struct CodeVersionSpecificFeatureConfig {
   pub staff: bool,
   pub non_staff: bool,
 }
 
 fn parse_code_version_specific_feature_config(
   value: Option<AttributeValue>,
 ) -> Result<CodeVersionSpecificFeatureConfig, DBItemError> {
   let mut code_version_config_map =
-    database::parse_map_attribute(FEATURE_FLAGS_CONFIG_FIELD, value)?;
-  let staff = database::parse_bool_attribute(
+    AttributeMap::try_from_attr(FEATURE_FLAGS_CONFIG_FIELD, value)?;
+  let staff = bool::try_from_attr(
     FEATURE_FLAGS_STAFF_FIELD,
     code_version_config_map.remove(FEATURE_FLAGS_STAFF_FIELD),
   )?;
-  let non_staff = database::parse_bool_attribute(
+  let non_staff = bool::try_from_attr(
     FEATURE_FLAGS_NON_STAFF_FIELD,
     code_version_config_map.remove(FEATURE_FLAGS_NON_STAFF_FIELD),
   )?;
   Ok(CodeVersionSpecificFeatureConfig { staff, non_staff })
 }
 
 #[derive(Debug)]
 pub struct FeatureConfig {
   pub name: String,
   pub config: HashMap<i32, CodeVersionSpecificFeatureConfig>,
 }
 
 fn parse_feature_config(
-  mut attribute_value: HashMap<String, AttributeValue>,
+  mut attribute_value: AttributeMap,
 ) -> Result<FeatureConfig, DBItemError> {
-  let feature_name = database::parse_string_attribute(
+  let feature_name = String::try_from_attr(
     FEATURE_FLAGS_FEATURE_FIELD,
     attribute_value.remove(FEATURE_FLAGS_FEATURE_FIELD),
   )?;
-  let config_map = database::parse_map_attribute(
+  let config_map = AttributeMap::try_from_attr(
     FEATURE_FLAGS_CONFIG_FIELD,
     attribute_value.remove(FEATURE_FLAGS_CONFIG_FIELD),
   )?;
   let mut config = HashMap::new();
   for (code_version_string, code_version_config) in config_map {
     let code_version: i32 =
       database::parse_integer("code_version", code_version_string.as_str())?;
     let version_config =
       parse_code_version_specific_feature_config(Some(code_version_config))?;
     config.insert(code_version, version_config);
   }
   Ok(FeatureConfig {
     name: feature_name,
     config,
   })
 }
 
 pub enum Platform {
   IOS,
   ANDROID,
 }
 
 #[derive(Clone)]
 pub struct DatabaseClient {
   client: Arc<aws_sdk_dynamodb::Client>,
 }
 
 impl DatabaseClient {
   pub fn new(aws_config: &aws_types::SdkConfig) -> Self {
     DatabaseClient {
       client: Arc::new(aws_sdk_dynamodb::Client::new(aws_config)),
     }
   }
 
   pub async fn get_features_configuration(
     &self,
     platform: Platform,
   ) -> Result<HashMap<String, FeatureConfig>, Error> {
     let platform_value = match platform {
       Platform::IOS => PLATFORM_IOS,
       Platform::ANDROID => PLATFORM_ANDROID,
     };
     let result = self
       .client
       .query()
       .select(Select::AllAttributes)
       .table_name(FEATURE_FLAGS_TABLE_NAME)
       .consistent_read(true)
       .key_condition_expression("#platform = :platform")
       .expression_attribute_names("#platform", FEATURE_FLAGS_PLATFORM_FIELD)
       .expression_attribute_values(
         ":platform",
         AttributeValue::S(platform_value.to_string()),
       )
       .send()
       .await
       .map_err(|e| {
         error!("DynamoDB client failed to find feature flags configuration");
         Error::AwsSdk(e.into())
       })?;
     if let Some(items) = result.items {
       let mut config = HashMap::new();
       for item in items {
         let feature_config = parse_feature_config(item)?;
         config.insert(feature_config.name.clone(), feature_config);
       }
       Ok(config)
     } else {
       Ok(HashMap::new())
     }
   }
 }