How I Built an AI Agent That Monitors My SaaS and Fixes Issues Before Users Notice

My SaaS has 2,400 users. I'm a solo dev. Two months ago I built an AI agent that monitors production and automatically fixes common issues. It's saved me from at least 3 outages. The Architecture Vercel (Next.js) → Sentry (errors) → Webhook → AI Agent → GitHub PR / Hotfix The agent runs as a Vercel serverless function triggered by Sentry webhooks. When an error hits a threshold (>5 occurrences in 10 minutes), the agent: Fetches the error details + stack trace from Sentry Pulls the relevant source files from GitHub Analyzes the root cause Generates a fix Runs the test suite against the fix If tests pass, opens a PR (or auto-merges for known safe patterns) What It's Fixed Automatically Database connection pool exhaustion — It detected the leak pattern and added proper connection cleanup Rate limit errors from a third-party API — Added exponential backoff that I'd been meaning to implement Null pointer in a new feature — Added a guard clause and a comment "auto-fixed: missing null check o