Microservice Architecture

Supported by Kong
application architecture   refactoring to microservices   microservices adoption  

Refactoring a monolith to microservices

Truly greenfield development of microservices-based applications is relatively rare. Many organizations that want to adopt microservices already have a monolithic application. As I describe in chapter 13 of my book, the recommended approach is to use the Strangler application pattern and incrementally migrate function from the monolith into services.

Presentations on refactoring

These presentations are good overviews:

About the FTGO monolith

The FTGO monolith (see source code) is the monolithic version of the microservices-based FTGO application. Its goal is to demonstrate how to refactor a monolithic application into services using the Strangler pattern. It’s used as an example in both my book and in my presentations about refactoring.

Refactoring strategies

Chapter 13 of my book describes how to refactor a monolith to microservices. There are two main refactoring strategies:

  • Implement new functionality as services
  • Extract services from the monolith

Let’s look at each one.

Implement new functionality as services

A good way to begin the migration to microservices is to implement significant new functionality as services. This is sometimes easier than breaking apart of the monolith. It also demonstrates to the business that using microservices significantly accelerates software delivery.

Extract services from the monolith

While implementing new functionality as services is extremely useful, the only way of eliminating the monolith is to incrementally extract modules out of the monolith and convert them into services. Here is an example of extracting a service from a monolith.

Signup to get notified

Signup to get notified when more content is added to this page.

application architecture   refactoring to microservices   microservices adoption  
Copyright © 2025 Chris Richardson • All rights reserved • Supported by Kong.

About Microservices.io

Microservices.io is brought to you by Chris Richardson. Experienced software architect, author of POJOs in Action, the creator of the original CloudFoundry.com, and the author of Microservices patterns.

ASK CHRIS

?

Got a question about microservices?

Fill in this form. If I can, I'll write a blog post that answers your question.

NEED HELP?

I help organizations improve agility and competitiveness through better software architecture.

Learn more about my consulting engagements, and training workshops.

LEARN about microservices

Chris offers numerous other resources for learning the microservice architecture.

Get the book: Microservices Patterns

Read Chris Richardson's book:

Example microservices applications

Want to see an example? Check out Chris Richardson's example applications. See code

Virtual bootcamp: Distributed data patterns in a microservice architecture

My virtual bootcamp, distributed data patterns in a microservice architecture, is now open for enrollment!

It covers the key distributed data management patterns including Saga, API Composition, and CQRS.

It consists of video lectures, code labs, and a weekly ask-me-anything video conference repeated in multiple timezones.

The regular price is $395/person but use coupon JIBFGJFJ to sign up for $95 (valid until May 16th, 2025). There are deeper discounts for buying multiple seats.

Learn more

Learn how to create a service template and microservice chassis

Take a look at my Manning LiveProject that teaches you how to develop a service template and microservice chassis.

Signup for the newsletter


BUILD microservices

Ready to start using the microservice architecture?

Consulting services

Engage Chris to create a microservices adoption roadmap and help you define your microservice architecture,

The Eventuate platform

Use the Eventuate.io platform to tackle distributed data management challenges in your microservices architecture.

Eventuate is Chris's latest startup. It makes it easy to use the Saga pattern to manage transactions and the CQRS pattern to implement queries.

Join the microservices google group

Topics

Note: tagging is work-in-process

Cynefin   ·  DDD   ·  GitOps   ·  Microservices adoption   ·  TODO   ·  ancient lore   ·  anti-patterns   ·  api gateway   ·  application api   ·  application architecture   ·  architecting   ·  architecture   ·  architecture documentation   ·  assemblage   ·  automation   ·  beer   ·  books   ·  build vs buy   ·  containers   ·  culture   ·  dark energy and dark matter   ·  decision making   ·  deliberative design   ·  deployment   ·  deployment pipeline   ·  design-time coupling   ·  developer experience   ·  development   ·  devops   ·  docker   ·  eventuate platform   ·  fast flow   ·  generative AI   ·  glossary   ·  health   ·  hexagonal architecture   ·  implementing commands   ·  implementing queries   ·  inter-service communication   ·  kubernetes   ·  loose coupling   ·  manning publications   ·  microservice architecture   ·  microservice chassis   ·  microservices adoption   ·  microservices platforms   ·  microservices rules   ·  microservicesio updates   ·  modular monolith   ·  multi-architecture docker images   ·  observability   ·  pattern   ·  pattern language   ·  refactoring   ·  refactoring to microservices   ·  resilience   ·  runtime coupling   ·  sagas   ·  scripting   ·  security   ·  service api   ·  service architecture   ·  service blueprint   ·  service collaboration   ·  service design   ·  service discovery   ·  service granularity   ·  service template   ·  software delivery metrics   ·  success triangle   ·  survey   ·  tacos   ·  team topologies   ·  technical debt   ·  testing   ·  transaction management   ·  transactional messaging   ·  wardley mapping

All content

Posts

20 Mar 2024 » A tour of two sagas
21 Dec 2023 » Thoughts about team size
24 Jul 2017 » Revised data patterns