Completing the Rewrite from Hell: Five Years of Technical Debt and How We Escaped - Aaron Stannard

This talk was recorded at NDC Copenhagen in Copenhagen, Denmark. #ndccopenhagen #ndcconferences #developer #softwaredeveloper Attend the next NDC conference near you: https://ndcconferences.com https://ndccopenhagen.com/ Subscribe to our YouTube channel and learn every day: / ‪@NDC‬ Follow our Social Media!   / ndcconferences     / ndc_conferences     / ndc_conferences   #architecture #dotnet #continuousdelivery #genai #data Bad architecture decisions don't just slow you down - they destroy business value. Poor coupling means you can't add the features customers are asking for. Data model mistakes mean you don't have the information to answer your questions, and a lot of your decisions can't be easily reversed. You know the problems are there. You've known for years. But there's never time to fix it properly - you're too busy keeping the lights on. Then one day, the stars align. You finally have time to tackle it. You open the codebase, ready to make things right - and realize you have no idea where to start. Everything is wrong. Every fix breaks something else. The whole thing feels impossible. I'm a business owner. I had full authority to prioritize this rewrite. No one to convince, no budget to fight for. I still couldn't make it happen for five years - even while watching money walk out the door. This is the story of how we finally completed that rewrite. You'll learn: Why we abandoned a full rewrite and pivoted to strategic refactoring instead How to assess whether your legacy system is salvageable (ours barely was) The architectural patterns - including the actor model - that would have prevented this mess How we used AI to accelerate the work (spoiler: it wasn't vibe coding) The management failures that let this happen, and how to avoid them This isn't a talk about how smart we are. It's about how we recovered from one of my biggest failures as an engineering leader - and what you can learn from our five-year journey through hell.