Microservices Migration Consulting

Before planning a microservices migration, Martin Fowler's 2015 observation is the published starting point: almost all the successful microservice stories started with a monolith that got too big and was broken up.

A microservices migration moves an existing application into separately deployed services. Fowler reports that systems built as microservices from the start have usually run into trouble, and he advises a monolith-first approach even for systems expected to grow large.

He also describes the advice as tentative and says some colleagues favor starting with microservices, especially teams with prior experience.

The pattern Fowler describes starts with a monolith that works and has grown too large. A migration plan for an application that is unstable starts with stabilizing it. In Company A, a month of bug fixing and an Angular upgrade came before any change to structure, and engineering cost fell from $48K to $8.7K a month.

Company B's first version cost about $15K but was so buggy it could not deliver key features, so a team of American contractors rewrote it. That second version cost about $37K a month for three years, about $1.3M in total, and was still unstable and unmaintainable. Both versions had no proper application architecture.

Both versions had the same underlying problem: no proper application architecture. The rebuild over 14 months fixed that, and maintenance fell to under $2K a month.