Every code base needs to be modernised at some point, either to reduce the technical debt or to migrate to another language. In such complex and challenging projects, automation is a key point to reduce the workload of low added-value tasks as monotonous refactoring or redundant paradigm translation.

To do so with our clients, struggled with deeply in-debt code bases, we built an in-house toolkit to support the developers in modernisation projects from detection to transformation. We created a language-agnostic model to represent code and several engines based on it: code smells and custom pattern detection, quality metrics, automatic refactoring, code generation… With this talk I would like to share what are the steps to build a toolkit to automate code’s transformation and share a few practical use cases.