The decision to migrate from a monolith to microservices is rarely straightforward. It involves trade-offs between operational complexity, team autonomy, and system reliability. This guide covers the practical steps we took during the Mitel to Dstny transition.
When to Migrate
Do not migrate because microservices are trendy. Migrate when your monolith causes real problems: deployment bottlenecks, team coordination overhead, or technology lock-in preventing innovation. If your team of five deploys once a week without issues, keep the monolith.
Strangler Fig Pattern
The strangler fig pattern is the safest migration approach. Build new functionality as independent services, and gradually route traffic away from the monolith. Over time, the monolith shrinks until it can be decommissioned. This approach allows you to validate each service in production before committing to the full migration.
Data Migration
Database decomposition is the hardest part of any migration. Start by identifying bounded contexts and their data ownership. Use the database-per-service pattern, but implement a data synchronization layer during the transition period. Event sourcing or change data capture (CDC) can keep the old and new databases in sync.
Observability First
Before migrating a single service, set up distributed tracing, centralized logging, and health monitoring. Without observability, debugging issues across multiple services becomes impossible. Use OpenTelemetry for standardized instrumentation, and ensure every service emits structured logs with correlation IDs.
Senior Software Engineer specializing in cloud architecture, real-time systems, and enterprise-scale applications.
