I run an AI Discord bot builder that's deployed 500+ live bots over the last year. The service takes a plain-English description, generates discord.js code, and ships the container to production in under 30 seconds.
That sounds clean. It is not clean.
Most of what I learned came from logs at 3am after someone's bot stopped responding to messages, or a community went silent because of an undocumented Discord behavior. Here's the list I wish I'd had on day one.
Missing Permissions (50013) is usually about role position, not permissions
The first time I hit this I spent two hours auditing the bot's permission integer. It was correct. The bot still couldn't kick anyone.
