diff --git a/services/feature-flags/Dockerfile b/services/feature-flags/Dockerfile
--- a/services/feature-flags/Dockerfile
+++ b/services/feature-flags/Dockerfile
@@ -32,4 +32,5 @@
 
 ENV RUST_LOG=info
 
-CMD ["feature-flags"]
+# For compatibility with the existing Terraform config
+CMD ["feature-flags", "--http-port", "50051"]
diff --git a/services/feature-flags/src/config.rs b/services/feature-flags/src/config.rs
--- a/services/feature-flags/src/config.rs
+++ b/services/feature-flags/src/config.rs
@@ -1,27 +1,21 @@
-use clap::{builder::FalseyValueParser, Parser};
+use clap::Parser;
 use once_cell::sync::Lazy;
 use tracing::info;
 
-use crate::constants::{
-  DEFAULT_LOCALSTACK_URL, HTTP_SERVER_DEFAULT_PORT, SANDBOX_ENV_VAR,
-};
+use crate::constants::HTTP_SERVER_DEFAULT_PORT;
 
 #[derive(Parser)]
 #[command(version, about, long_about = None)]
 pub struct AppConfig {
-  /// Run the service in sandbox
-  #[arg(long = "sandbox", default_value_t = false)]
-  #[arg(env = SANDBOX_ENV_VAR)]
-  #[arg(value_parser = FalseyValueParser::new())]
-  pub is_sandbox: bool,
-  /// AWS Localstack service URL, applicable in sandbox mode
-  #[arg(long, default_value_t = DEFAULT_LOCALSTACK_URL.to_string())]
-  pub localstack_url: String,
-  #[arg(long = "port", default_value_t = HTTP_SERVER_DEFAULT_PORT)]
+  /// AWS Localstack service URL
+  #[arg(env = "LOCALSTACK_ENDPOINT")]
+  #[arg(long)]
+  pub localstack_endpoint: Option<String>,
+  #[arg(long, default_value_t = HTTP_SERVER_DEFAULT_PORT)]
   pub http_port: u16,
 }
 
-pub static CONFIG: Lazy<AppConfig> = Lazy::new(|| AppConfig::parse());
+pub static CONFIG: Lazy<AppConfig> = Lazy::new(AppConfig::parse);
 
 pub fn parse_cmdline_args() {
   Lazy::force(&CONFIG);
@@ -30,12 +24,9 @@
 pub async fn load_aws_config() -> aws_types::SdkConfig {
   let mut config_builder = aws_config::from_env();
 
-  if CONFIG.is_sandbox {
-    info!(
-      "Running in sandbox environment. Localstack URL: {}",
-      &CONFIG.localstack_url
-    );
-    config_builder = config_builder.endpoint_url(&CONFIG.localstack_url);
+  if let Some(endpoint) = &CONFIG.localstack_endpoint {
+    info!("Using Localstack. AWS endpoint URL: {}", endpoint);
+    config_builder = config_builder.endpoint_url(endpoint);
   }
 
   config_builder.load().await
diff --git a/services/feature-flags/src/constants.rs b/services/feature-flags/src/constants.rs
--- a/services/feature-flags/src/constants.rs
+++ b/services/feature-flags/src/constants.rs
@@ -1,8 +1,6 @@
-pub const DEFAULT_LOCALSTACK_URL: &str = "http://localhost:4566";
 pub const LOG_LEVEL_ENV_VAR: &str =
   tracing_subscriber::filter::EnvFilter::DEFAULT_ENV;
-pub const HTTP_SERVER_DEFAULT_PORT: u16 = 50051;
-pub const SANDBOX_ENV_VAR: &str = "COMM_SERVICES_SANDBOX";
+pub const HTTP_SERVER_DEFAULT_PORT: u16 = 50055;
 
 // The configuration of feature flags is stored in a table in DynamoDB.
 // Each row is identified by a compound primary key consisting of
diff --git a/services/feature-flags/src/service.rs b/services/feature-flags/src/service.rs
--- a/services/feature-flags/src/service.rs
+++ b/services/feature-flags/src/service.rs
@@ -5,6 +5,7 @@
 use comm_services_lib::database::Error;
 use serde::{Deserialize, Serialize};
 use std::collections::HashSet;
+use tracing::info;
 
 pub struct FeatureFlagsService {
   db: DatabaseClient,
@@ -16,6 +17,11 @@
   }
 
   pub async fn start(&self) -> std::io::Result<()> {
+    info!(
+      "Starting HTTP server listening at port {}",
+      CONFIG.http_port
+    );
+
     let db_clone = self.db.clone();
     HttpServer::new(move || {
       App::new()