From Monolith to Microservices: A Practical Migration Playbook

The Rewrite Trap

The temptation to start from scratch is strong. But a full rewrite means months, sometimes years, without delivering value, while the old system still needs maintenance.

A better approach: strangler fig migration.

The Strangler Fig Pattern

1. Identify seams: Find natural boundaries in the monolith (modules, bounded contexts).
2. Extract at the edge: Start with low-risk, high-value services (authentication, notifications, reporting).
3. Route incrementally: Use an API gateway to direct traffic between old and new services.
4. Decommission gradually: Once a service is fully extracted and stable, remove the corresponding monolith code.

Common Pitfalls

• Distributed monolith: Extracting services that still share a database. Each service needs its own data store.
• Premature decomposition: Not every module needs to be a separate service. Start coarse-grained.
• Ignoring observability: Distributed systems fail in distributed ways. Invest in tracing and centralised logging from day one.

Our Approach

At ViyoraTech, we run a discovery phase before writing any migration code. We map dependencies, measure coupling, and prioritise extraction candidates by business impact and technical risk.

The goal is never microservices for their own sake. It is the right architecture for the problem at hand.