Microservices vs. Modular Monolith: What's Right for Your Business in 2025?

The Microservices Backlash Is Real

After years of unbridled enthusiasm, engineering teams are quietly migrating back to simpler architectures. The operational overhead of managing dozens of services — each with its own deployment pipeline, monitoring, and failure modes — has proven too costly for many organizations.

The Case for the Modular Monolith

A well-structured modular monolith provides most of the benefits of microservices (clear domain boundaries, team autonomy) without the distributed systems complexity. Companies like Shopify have famously championed this approach.

When Microservices Still Make Sense

True microservices shine when you have: independent scaling requirements per service, large teams (50+ engineers) that need autonomous deployment, or genuinely different technology stacks for different domains (ML inference alongside CRUD operations).

The Decision Framework

Start with a modular monolith. When a specific module needs independent scaling or a separate team, extract it into a service. This "strangler fig" approach lets you evolve your architecture based on actual constraints rather than anticipated ones.

FBG's Approach

For our clients with teams under 20 engineers, we nearly always recommend starting with a well-structured modular monolith using domain-driven design principles. We've helped several companies successfully extract services from their monolith when genuine scaling needs emerged.