I'll share a few.
1. Don't get tunnel visioned into the problem you're solving. Prioritize maintaining your professional relationships, especially with your manager, over all else. Prioritize what your manager cares about over whatever you think is more important.
2. Async-communication does not replace real-time communication. People cannot help but reveal more when you're communicating in real-time. This is crucial because of the next point.
3. Do NOT assume good intentions. Sadly, the tech industry is full of backstabbers across organizations of all size. If people have an issue with how you're doing something, no matter how small, no matter how trivial, expect that it'll go directly to your manager and be kept hidden from you.