My name is Martin Fowler: I’m an author, speaker, and loud-mouth on the design of enterprise software. This site is dedicated to improving the profession of software development, with a focus on skills and techniques that will last a developer for most of their career. I’m the editor of the site and the most prolific writer. It was originally just my personal site, but over the last few years many colleagues have written excellent material that I’ve been happy to host here. I work for ThoughtWorks, a really rather good software delivery and consulting company. To find your way around this site, go to the intro guide.
News and Updates
My atom feed (RSS) announces any updates to this site, as well as various news about my activities and other things I think you may be interested in. I also make regular announcements via my twitter feed, which I copy to my facebook page.
Wed 23 Aug 2017 14:46 EDT
ThoughtWorks, my employer, had some big news to share today. Our founder and owner, Roy Singham, has decided to sell ThoughtWorks to Apax - a private equity firm based in London. Apax wishes the current management team to continue running and growing ThoughtWorks, using the same model that's driven our growth and success for the last twenty-odd years.
Mon 07 Aug 2017 11:57 EDT
Paul Hammant shines a light on Test Impact Analysis: a modern way of speeding up the test automation phase of a build. It works by analyzing the call-graph of the source code to work out which tests should be run after a change to production code. Microsoft has done some extensive work on this approach, but it's also possible for development teams to implement something useful quite cheaply.
Sat 10 Jun 2017 09:48 EDT
Wed 24 May 2017 13:22 EDT
Gregor Hohpe has taken his experience with ThoughtWorks and Google to a traditional insurance company. As an enterprise architect he sees his role as riding the elevator between the executive penthouse and the IT engine room and passes on his advice for architects to bring modern digital practices to traditional enterprises.
Mon 15 May 2017 09:32 EDT
Ryan Lockard (Agile Uprising) invited me to join Rebecca Wirfs-Brock for a podcast conversation on architecture on agile projects. Rebecca developed Responsibility-Driven Design, which was a big influence for me when I started my career. We talked about how we define architecture, the impact of tests on architecture, the role of domain models, what kind of documentation to prepare, and how much architecture needs to be done up-front.
Thu 11 May 2017 15:00 EDT
Last week I gave the opening keynote at goto Chicago. For a topic, I decided to go into the results of ThoughtWorks's Event-Driven architecture summit that I wrote some notes on earlier this year. The talk expands on those, explaining the four patterns that we felt were a better way of talking about these architectures.
Refactoring has become a core skill for software developers, it is the foundation behind evolutionary architecture and modern agile software development. I wrote the original book on refactoring in 2000, and it continues to be an interest of mine.
I’ve recently posted several essays on refactoring here:
- While most of our logic is written directly in an imperative language, it is sometimes very useful to represent such logic in a data structure. Refactoring to an Adaptive Model describes this refactoring, which produces an adaptive model interpreted by generic code.
- When I write code that deals with external services, I find it valuable to separate that access code into separate objects. Refactoring code that accesses external services shows how I would refactor some congealed code into a common pattern for this.
- Modern languages give us the opportunity go beyond the loop as a way of handling repetitive behavior. Refactoring with Loops and Collection Pipelines provides a series of small examples of refactoring loops into my preferred approach.
- Refactoring Code to Load a Document looks at how manipulating large JSON documents can often be made easier by encapsulating a combination of loading strategies.
I discovered ThoughtWorks in 2000: then a small American company whose philosphy of software development was remarkably similar to my own. Now we’ve grown to around 4000 people world-wide, but kept the values that make us special. My colleagues have built critical systems for many clients in that time, and I’ve learned many lessons from them. While doing this, we found we often didn’t have the tools we needed, so we started to build them. This led to open-source tools such as CruiseControl, Selenium, Frank, and Moco as well as commercial products.
I have many opportunities, but I’ve stayed at ThoughtWorks because of the quality of my colleagues, who include both well-known speakers and those who may not be famous names but do an excellent job of software delivery (and feed me the information to write about). We are inspired by working with each other and our unusual three-pillar philosophy that raises professional excellence and social justice to the same level as financial performance.
And we are always looking for more great people to join our curious company. Maybe I’ll see you in one of our offices some day.
Continuous Integration and Delivery
For a long time I’ve been a champion of Continuous Integration which reduces integration risk by integrating early and often, an application of the principle of Frequency Reduces Difficulty. We’ve found CI to be a core technique at ThoughtWorks and use it almost all the time. At the heart of this is a style of development that minimizes long feature branches with techniques like Branch By Abstraction and Feature Toggles.
While this is useful, there was still risk present from software that works in the development environment to getting it to work in production. As a result we developed Deployment Pipelines to reduce this risk, moving closer to our aim of Continuous Delivery: building software in such a way that we confidently deploy the latest builds into production whenever there is a business need. We find this improves feedback, reduces risk, and increases the visibility of project progress.
For more information: take a look at my guide page on Continuous Delivery.