Legacy code. The sheer mention strikes fear into the hearts of C++ developers. Whether you are a veteran or a newcomer to the language, the idea of grappling with an outdated, convoluted codebase full of outdated practices and C-style implementations can be daunting indeed. Many would prefer the allure of building something new and exciting, free from the constraints of a legacy system.

Yet, what if you do not have this luxury? Legacy code is valuable and remains the backbone of countless living and breathing applications. Simply keeping these applications alive is not good enough. Their code needs to be understood, future-proofed, updated to new language standards, and made less brittle if the application is to survive.

But how you can even begin to understand and modify code without any existing tests? In this talk we will explore practical strategies for confidently working on large legacy C++ codebases and getting them shipshape. Who knows, you might even find using these actionable approaches enjoyable.