AWS Lambda's autoscaling model creates a fundamental mismatch with Aurora Serverless v2's connection limits, causing connection pool exhaustion, zombie connections, and cold start penalties during traffic spikes. AWS's own RDS Proxy solution adds complexity without fully resolving the problem. Neon, a serverless Postgres alternative, addresses this by integrating PgBouncer directly into every endpoint, supporting up to 10,000 concurrent connections via transaction pooling mode — activated simply by adding '-pooler' to the connection string. A practical walkthrough demonstrates deploying Lambda functions with Neon using the Serverless framework, with load tests showing pooled connections handling 7,799 requests with only 8 actual DB connections versus 93 connections without pooling. Neon also autoscales compute and memory in response to load, further improving resilience.
