Definitions

Monolith: one codebase, one deployment.

Microservices: many small services.

Modular monolith: separated internally, deployed together.

Different tradeoffs.

Monolith Advantages

Simple deployment.

Easy debugging.

Fast development.

Simple transactions.

One database.

Perfect for MVP and early stage.

Monolith Disadvantages

Scaling: whole thing scales together.

Team coordination as size grows.

Technology lock-in.

Deployment risk grows.

Compile/build times increase.

Microservices Advantages

Independent scaling.

Technology diversity.

Team autonomy.

Fault isolation.

Continuous deployment.

Microservices Disadvantages

Distributed system complexity.

Network latency.

Debugging harder.

Deployment orchestration.

Data consistency challenges.

Infrastructure cost.

The Modular Monolith Middle Ground

Well-structured internal modules.

Clear boundaries.

Same deployment.

Can extract to services later if needed.

Best of both for many cases.

When Monolith Works

Team under 20.

Product under 1M users.

Traffic under 10K requests/sec.

Simple domain.

Startup or growth stage.

When Microservices Make Sense

Team over 50.

Different domains/teams.

Different scaling needs.

Different technology needs.

Enterprise scale.

The Coordination Cost

Microservices: services communicate.

Network calls have latency.

Failures cascade.

Circuit breakers, retries needed.

Every call has cost.

Data Consistency

Monolith: transactions across data.

Microservices: distributed transactions hard.

Saga pattern for workflows.

Eventual consistency common.

Deployment Complexity

Monolith: deploy one thing.

Microservices: deploy 20+ services.

Coordination.

Versioning.

Rollback strategies.

Observability

Monolith: usually simpler.

Microservices: distributed tracing needed.

Log correlation.

Service dependency mapping.

Migration Path

Monolith → Microservices painful.

Extract one service at a time.

Strangler pattern.

Years, not months.

Don’t do prematurely.

Common Mistakes

Microservices from day 1 (over-engineering).

Breaking monolith too early.

Microservices without proper infra.

Nano-services (too small).

Not aligned with team structure.

Conway’s Law

Software mirrors organization.

Team structure = architecture.

5-person team + microservices = disaster.

Consider org before architecture.

The Netflix Story

Netflix microservices success is exception.

Also: hundreds of engineers, unique scale.

Not applicable to most.

Cargo culting harmful.

Our Recommendation

MVP and early stage: monolith.

Growth stage: modular monolith.

Scale + organization complexity: consider services.

Never microservices before need.

Never break monolith prematurely.

Based on Real Projects

This guide is based on our work with:

• Platforma365
• Nasca

Further Reading

If this guide helped you, you might also want to read our comprehensive guide on Custom SaaS Development.