Such a great opportunity to get in as an engineer and make a difference. The good news is the code is running in production and generates revenue! From here you

Such a great opportunity to get in as an engineer and make a difference. The good news is the code is running in production and generates revenue! From here you can start making small incremental changes. I would start in this order. 1. Make it script version controlled. 2. modularise the code. This will help in understanding the structure. 3. Add the dependency management. 4. improve the code deployment process. CI/CD etc.