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Debugging

Header: 'Webhooks that fail one time in ten.' beside an illustrative webhook log: a 401 signature mismatch on an amount of 24.50, the same event handled twice after a slow 4.1 s response and a retry, and a fast queued 200.

Debugging webhooks in Node: failed signatures, retries and duplicate events

Webhook bugs rarely reproduce on your laptop: a signature check that fails one time in ten, the same event processed twice, a retry storm after a slow deploy. Here's the fix for each, plus how to get the exact request in front of you.

Jason Fill November 5, 2026 6 min read

Header: 'Your API isn't slow. It's waiting for a connection.' beside an illustrative terminal showing a pg pool with 10 total, 0 idle and waiting climbing from 47 to 240, and GET /v1/dashboard at p95 9.8s with 80 ms of database time.

Debugging

Your Node API isn't slow. It's waiting for a database connection.

Fine in testing, then 200 people open the same page and the endpoint takes ten seconds. CPU is flat and Postgres says every query is fast. That's pool starvation. Here's why it happens in Node, how to spot it, the fixes with code, and how to prove they worked.

Jason Fill November 3, 2026 6 min read