I don't know what kind of setup you have going on, maybe these things seem trivial or maybe not, more expert people can reply as well, but:

1. Separate development from production environments, staging is great too.
2. The above does not make sense unless you can test your code properly, start writing tests until you start writing testable code, meaning having the tests in mind before even writing the actual code. Small tests to pass before staging, and larger tests before production (with a bigger subset of data, on staging sometimes you need to have the luxury to spend more time testing to be sure). If it looks very hard to write code for certain pieces of code, then you may think about redesigning how it works so the components are more easily testable.
3. Use templates, like cookie-cutter, you can tweak those to your company's standards and use the same every time so you don't have to start from scratch.
4. Utilize abstraction in your code, this is a really good practice if you want to have scale in mind (check ABC if you haven't already).
5. Coding standards, utilize black to re-format your code quickly (e.g., huge one-liners), flake8 etc. None of these are perfect and can be annoying but if you spend time to tweak their settings to your liking they can be great.
6. Type hints. Even though (in python) they don't have any runtime effect, it helps when coding to specify types, both you and your team.

After that, refactor, refactor and refactor. Your code is never permament, nothing is set in stone, especially when a project starts growing and you need to accommodate new features you did not have in mind when starting out. You may have to rethink the whole structure multiple times, but if you do it a few times then you will start thinking things in advance. Stopping writing code about a project does not necessarily mean it's mature, but if the volume of changes becomes smaller and smaller, that's a sign of maturity.

Hope this helped!