Running PHP applications on AWS Lambda usually means giving up traditional session management. Storing session data on local filesystems doesn't work when Lambda instances are ephemeral. Most developers turn to Redis or ElastiCache, but that adds infrastructure complexity and maintenance.

This deep dive shows how to build a truly serverless PHP app using Bref, Symfony, and DynamoDB for session storage. The solution replaces PHP's default session handler with a custom DynamoDB-backed handler, eliminating the need for Redis entirely. Sessions are stored with automatic expiration using DynamoDB's TTL feature.

The architecture separates stateful data (sessions, CSRF tokens) in DynamoDB from stateless application logic running in Lambda. Deployment uses AWS CDK and Lambda Function URLs for HTTPS endpoints, avoiding API Gateway complexity. Why it matters: This approach removes infrastructure friction while maintaining scalability.

It's ideal for apps with unpredictable traffic, internal tools, or multi-tenant SaaS platforms where operational overhead needs to stay minimal.