Pavel Kleisner

Quest log

Abilities

Integrations

B2B APIs, message contracts, retries and the failure modes that only show up once a partner system is connected.

Releases

New platform versions into real environments: old data, backward compatibility, rollout order and a way back.

Debugging production

Logs, metrics, the database and domain knowledge together. I look for the cause, not for a patch that makes the symptom go quiet.

Architecture

Small safe changes, clearly named rules and sensible service boundaries. As little ceremony as the problem allows.

Companion AI in the party

• I use AI agents every day and I've learned to get a lot out of them: exploring an unfamiliar codebase, drafting the boring parts, running tests, preparing migrations and reviewing a diff before I do.
• It makes me noticeably faster and lets me take on work I wouldn't have had time for.
• It doesn't take the controller. I read and understand every line that ships under my name, and when production breaks, the analysis and the fix are mine.

Boss fight The UUID that wasn't a UUID

When we rolled out the first platform version, the integration spec said the messageId would be a UUID. One partner started failing straight away: their system had been quietly parsing the ticket ID out of the old ticketId_timestamp format, even though the ticket ID sat right there in the message body.

The clean fix was on their side, but in a corporate setting it would have taken months. So I switched our side back to the old shape and production kept running. Sometimes the right call isn't the pure one. It's the one that doesn't break someone else at 2 a.m.

Skill tree

Main

Kotlin, Java, Spring, PostgreSQL, Kafka

Also unlocked

Kubernetes, Oracle, Angular, Python and Django, TypeScript, Astro

Current save

Playing

Bayonetta 3

Reading

Citadela — Alexej Osadčuk

Watching

One Piece