When you are beginning to consider refactoring your big legacy codebase towards a new software design, then it is not uncommon to feel helpless after estimating this to be a huge terrifying 2-5 years project. To help solve the problem of not knowing where and how to begin, we have had great success using a decision matrix to decide how each part of the legacy code should be changed in such a refactoring project. Two main factors should influence your refactoring decisions ..read more

Many projects I join - even those that claim to already do dependency injection - suffer from issues that result from mixing injectable and newable classes. Keeping these two appart seems to be challenging for many developers so that I try to give them a handy guide with Do's and Dont's in this blog post ..read more

Setting up a load-test that produces results you can rely on is not that simple. But without realistic test-results you cannot be sure that your application handles sudden increases of traffic, rapid spikes or even the initial go-live. And you cannot estimate at which number of users you should scale up your hardware. Both details are very important to keep the application running at all times and guarantee that no revenue or developer sleep is lost because of outages. We have a large checklist of points we go through when setting up performance tests with customers and I wanted to discuss som ..read more

You are working for months on a new web application or e-commerce system and usually a few weeks or just days before the launch a complete enough feature set is running on a production-like system so that you can run a realistic load-test. Hopefully providing you with accurate picture of the performance of your future system. What should you do, and why is Apache Benchmark usually not sufficient ..read more

There are many different ways to teach topics of software developments. From recorded lectures to pair programming. Over the time we tried many of them with different customers and different topics. I want to provide you with an overview of what worked best for us for which topic ..read more

So your code base is littered with singletons and using them? Don't worry, you can start refactoring them out of your code base class by class and introduce increased testability at every step. This strategy is very simple to implement and the propability of breaking your code is very low, especially when you are becoming more experienced with this technique ..read more

The second version of our book "Crafting Quality Software – Gems From the Qafoo Blog" is ready and available for download from now on. In the recent months we wrote a lot about refactoring techniques, technical patterns and workflows. This is a topic very close to our hearts and we feel that an update of our book was due ..read more

After you got the hang of unit testing there is still so much space for improvement. In this post I want to share five tips with advanced testers I have seen to influence testing in the right direction ..read more

When we join teams to coach them with refactoring their legacy code base, many of them are overwhelmed by the sheer mass of code. That typically results in the request for "some refactoring sprints" or even "a complete rewrite". Both is obviously not a solution from the business perspective - feature development and bug fixing needs to go on and the refactoring should not eat up the larges portion of time. But where and how should the team start and how should? What we call the "Advanced Boy Scout Rule" has helped many teams to come over this staleness and reach fast results while continuing t ..read more

Software systems usually get more complex over time. In the beginning a variable starts out to represent something very simple with very few rules and constraints that can are enforced in a single location of the code. We will show you how you can use value object extraction to avoid spreading logic everywhere ..read more