What made it great: the company is 7 years old, I work basically since inception, half year late.
The codebase had some serious problems due to migrating build systems, rapid team growth and lack of proper communication while developing important infrastructure tools, lack of foresight at the start of a crucial requirement for the whole system that became clear 3 years in.
Aaand… Due to unique sequence of events half a year ago we had to start everything from scratch! We could not use a line of code from the old repo !
This brought miracles out! We started designing the right things right. People started talking to each other on the global scale, without the code limiting them!
The old code not only had problems on the engineering level, but it held people and team responsibilities along suboptimal interface boundaries! This is the biggest magic! After the rewrite started, all the people in the team landed exactly where they wanted and their areas of responsibility became clear and highly efficient. Some people started shining like I could not imagine. Because their organizational and communication skills were limited by a huge suboptimal codebase.
Also, it is very empowering to design a system when your whole team has real experience 5 years into the future. Also, everyone turned out to be caring about code simplicity and quality, I finally feel at home.
I could not wish for a better developer experience. The sexiest C++ coding time in my life :)