As a consultant, you get tasked with a variety of stuff. Last few weeks been struggling to maintain an old C++ application that was written by a complete tool of an a$$hole with zero knowledge on how to write maintainable and production quality code. It would hardly run without a crash. First it was a challenge I had to accept, but as I stabilized the code and just fell over even more traps, I had to admit defeat and review my approach.

Rewrite is something I would choose last, but this one ticked all the marks worthy of a rewrite. So, the customer is a very friendly researcher and gladly spent 15 hours with me explaining all the math and concepts - just a delight for a programmer to have such a customer. Two days in, with a DDD approach - a functional, more precise, faster and stable application.

Sometimes there is no rant to share, it's rare to have that perfect communication with a customer that is so dedicated that he spends so much time teaching you his speciality and actually understand your approach. DDD was really a lifesaver here, by using it's key concepts and ubiquitous language. The program is essentially 8000 lines of math, but wrapping it up with value objects and strong domain models made me understand his domain and him mine. It also allowed me to parallelize the computations, giving me a huge performance boost. Textbook approach, there will not be many like this!