Stop fixing the same error twice.
Deep dives and playbooks behind the runbooks: the pool math, the retry rules, the DNS records. Every guide links straight to the error pages it explains.
P2024 on serverless: the connection-pool math nobody does
Every cold start opens its own pool. Here is how 40 Lambdas turn into 200 Postgres connections, and the three settings that bring it back to 40.
Read the guide →Three 429s, three meanings: OpenAI, Anthropic and Gemini
The same status code means “slow down” at one provider and “pay your bill” at another. Here is how to tell them apart in one catch block.
Retry or fix? A decision tree for every error in your logs
Half of all retry loops make incidents worse. Four questions decide whether to back off and try again, or stop and change the request.
Reading revert data like a stack trace
0xe450d38c followed by 192 hex characters is not noise. It is a function call in reverse, and you can decode it in one line.
Cloudflare 52x errors, explained by where the request died
520, 522, 524 and 525 each name a different hop between the edge and your origin. Draw the path once and the fix is obvious.
401 or 403? Ask one question
“Do I know who you are?” If no, 401. If yes but you can’t do this, 403. Everything else is detail.
Make 550 5.7.1 go away: SPF, DKIM and DMARC in 20 minutes
Since 2024 Gmail and Yahoo reject unauthenticated bulk mail outright. Three DNS records fix most of it.
Next.js hydration errors: the five causes, ranked
Dates, window checks, invalid HTML nesting, random IDs and browser extensions. In that order.
ERR_REQUIRE_ESM in 2026: you might just need to upgrade Node
require() of ES modules works by default since Node 22.12 and 20.19. When it still fails, it is one of two edge cases.
Postgres deadlocks are retryable. Lock ordering makes them rare.
40P01 is Postgres doing its job: it picked a victim so the other transaction could finish. Retry the victim, then fix the order.