Legacy Monolith Migration to Modular Services
We migrated a decade-old monolith into modular services with phased cutovers, reducing release risk and outage frequency.
Independent deploy paths let teams ship on their own schedule instead of one monthly release train.
Service isolation reduced blast radius when one subsystem failed.
Build and deploy pipelines moved from manual runbooks to automated CI workflows.
Right-sized workloads replaced overprovisioned monolith infrastructure.
Project Details
Problem
A single monolith served multiple product lines. Any release risked unrelated areas, and incident recovery required all-hands debugging.
Approach
We decomposed high-change domains first, introduced event contracts between services, and ran dual-write cutovers by subsystem. The trade-off was temporary complexity while old and new paths ran in parallel.
Result
The platform moved to safer incremental releases with fewer high-severity incidents and faster recovery.
What Could Be Better
One early cutover produced schema drift between legacy and new services. We added contract tests and migration guardrails before the next phase.