A service is judged by its own span, not by the client's stopwatch.

👋 Hi, I'm Anton - a software engineer working mostly in PHP/Symfony and Go, currently carving a live PHP monolith into Go services. This series is about one write path that left the monolith and what it took to accept it as working. This part is about latency: where it actually sits, and how long we argued about it before anyone measured. Running notes live on my GitHub: github.com/brilliant-almazov .

This is how I do it right now, with the price attached - maybe you already do it better, maybe you'd do it another way.

The path in one paragraph

One feature: a user saves a set of matching rules, and every domain under that account gets marked according to them. Four participants. The Go API gateway is the only door from outside. The rule-set-markup service takes the write, folds the cascade and persists it. The domain-rule-map service owns rule-set identity and does the recalculation, with a worker process behind a queue.…