system-design – Page 3 – Türker Yıldırım

A single binary against a runtime, costed

NoteNovember 25, 20252 min read

A recurring proposal to move a service to a compiled language, costed properly rather than argued about. The performance difference is real and is irrelevant to the caller,…

The backup that had to leave the building

Deep diveNovember 11, 20259 min read

Every backup in one provider’s object storage, and a disaster recovery plan that assumes the disaster is local.

The dependency graph generated from source, not from memory

NoteNovember 6, 20251 min read

A module diagram maintained by hand since 2023, compared against the graph the code actually forms. Four edges that do not exist are aspirational and six that are…

Boundaries drawn on a whiteboard, and the test that checks them

Deep diveNovember 4, 202510 min read

A module diagram from 2023 and a codebase that has moved since. A diagram everybody references and nobody has checked.

The incident that was a certificate, again

Deep diveOctober 10, 202510 min read

The third certificate incident in six years, each with a different cause. An expired certificate on a service nobody remembered was serving TLS.

Ten years of a codebase, read in one week

Deep diveOctober 9, 202510 min read

A decade of an application, and a week spent reading it rather than changing it. Decisions re-litigated because nobody knows what is already there.

The archive table nobody could delete from

Deep diveOctober 6, 202510 min read

900 million rows, a retention policy, and a legal question nobody had asked. A table that grows forever because deleting from it might be illegal.

A test suite that runs on every commit, in ninety seconds

Deep diveSeptember 25, 20259 min read

Four minutes forty is fine and ninety seconds changes behaviour. The threshold below which running the suite stops being a decision.

The read model that finally earned its place

Deep diveSeptember 24, 202510 min read

A projection deleted in 2023 for being premature, rebuilt in 2025 because the query is now eleven seconds.

Docker Compose in production, and why it is still here

Deep diveSeptember 19, 202510 min read

Six years of Compose on a VPS, and an annual conversation about orchestration. Nothing is wrong, which is why the conversation keeps happening.