system-design – Page 9 – Türker Yıldırım

Extracting a module without extracting a service

Deep diveFebruary 3, 202314 min read

A billing module everybody agrees should be separate, a team of four, and 88 classes that reference it. The boundary, drawn in code rather than in conversation.

An objective that was a guess, written down as a guess

NoteJanuary 26, 20232 min read

A service level objective invented in a meeting is a guess, and the useful move is to say so in the document rather than to pretend otherwise. An…

Readonly classes and the DTO that stopped needing a constructor

Deep diveDecember 20, 202210 min read

8.2 on 8 December, and readonly applied to a whole class. readonly on every property, written out forty times.

Larger runners, and the pipeline that was memory-bound

Deep diveDecember 13, 202210 min read

October, larger runners, and a build that was swapping. A Node build that used 6 GB on a 7 GB runner.

The dynamic property that had been a typo since 2016

Deep diveDecember 13, 202214 min read

8.2 on 8 December deprecates dynamic properties, and the deprecation is the feature. $order->totl has been silently creating a property for six years.

The webhook we sent, and the retries we owed

Deep diveDecember 7, 202210 min read

Being the sender, for the first time, and the obligations that come with it. A customer endpoint that was down for six hours.

The boundary that is a file, not a shared database

NoteNovember 30, 20222 min read

A batch job in another language integrated through a shared schema couples the two deployments; integrated through a file it does not. A file with a documented schema…

A design system in theme.json and a stylesheet that agrees

Deep diveNovember 17, 202210 min read

6.1, fluid typography, and a stylesheet that had its own scale. Two definitions of a spacing scale, one in each place.

Rotating a webhook secret without breaking subscribers

NoteNovember 16, 20221 min read

A secret that can only be replaced atomically cannot be rotated without coordinating a deploy on somebody else’s system. The multi-value header is the arrangement every large provider…

A pipeline that only builds what changed

Deep diveNovember 15, 202210 min read

A 22-minute pipeline on a repository where most changes touch one directory. Every push runs everything, including the untouched.