Why Your PostgreSQL Keeps Running Out of Connections

PostgreSQL connection errors are one of those things that look terrifying when they hit production. I used to think: "Why is the database refusing connections?" "Did something crash?" "Is the server overloaded?" 😅 Recently, while working on a production system, I ran into the classic TooManyConnectionsError . Not once twice. On two different services. Same database, same root cause. That experience helped me clearly understand why this happens and how to fix it properly. This post is me breaking that down in a simple way, based on what actually worked. What does TooManyConnectionsError actually mean? In simple terms, PostgreSQL has a limit on how many connections it allows at the same time. This limit is set by max_connections and is usually: 50–100 for small/basic tiers 100–200 for general purpose tiers When your application tries to open more connections than this limit, PostgreSQL says no. That's the error. The important thing to understand: The database isn't down. It just has no r