Why 50 Concurrent Playwright Sessions Backfire and How to Fix Them

Running large numbers of simultaneous Playwright browser sessions in agent workflows triggers CAPTCHAs, spikes CPU usage, and causes cascading retry failures that stall entire pipelines. The core problem is not the target website but the automation's own concurrency model, where bursty traffic to a single domain appears bot-like while unstable browser contexts consume memory. Developers recommend capping active sessions to between 5 and 10, queuing overflow tasks in memory or Redis, and pacing requests to the same domain one to three seconds apart. Retries should be limited to three attempts with exponential backoff, and stuck sessions should be killed after a 30-second timeout. For distributed or multi-container setups, Redis-backed queuing offers a more durable way to manage session slots across workers.