Twilio Segment collapsed 140+ destination-specific microservices into a single monolith, one repo, one set of dependencies, one test harness.
They leveled out version sprawl and built Traffic Recorder, a homegrown yakbak-based HTTP playback tool. That killed off hours-long test runs, dropping them to milliseconds. CI finally stopped flaking.
The monolith didn’t just simplify deployments, it cut down incidents and let teams move faster on shared code.
