What's the best way to prepare 'before' joining the next team/company?

I'm thinking to glance over some materials about the tech stack that the new team uses before joining them.

I think this makes sense, but I have a couple thoughts here (including a potential caveat):

• Databricks is huge. This means that their stack is almost certainly quite different from the vanilla books/tutorials out there as every big company does custom stuff. I would consume some basic resources (especially if it's a new language/stack), but I wouldn't spend more than a week on it. You're going to hit huge diminishing returns.
• Ideally, ask your manager for what they think will be helpful. Maybe they have some recommendations on what things out there are actually applicable to the team's system.

The main thing you should do to prepare is to figure out the people side. Here's a checklist:

• Talk to the manager - Here's a Q&A going over good questions to ask: "What questions can I ask to my to-be manager about the team I'll be joining?"
• Ask for a dedicated onboarding mentor - Do this when you have that call with the manager - If they don't have time for a call, do it through email. You can phrase it as something like, "I'm really excited to make an impact on your team and hit the ground running as soon as possible. Could I have a dedicated onboarding mentor during my first month at the company?" Worst case, the manager just says "No", but I think this has a good chance of working out. It shows you're really passionate about the team, and the incentives align (what kind of manager wouldn't want their new hire to just start crushing it?). I had a dedicated onboarding buddy at Robinhood, and they were so helpful - This practice really should be standardized to every company ever.
• Talk to other engineers on the team - You can also ask for this during the meeting with the manager; either the manager can set it up for you, but if they're too busy, just try to get their emails and set it up yourself. The tech lead is the most important person here. Relationship-building is so important, and there's no reason you can't start it before you join the company if you already are tied a certain team (the tricky part is you probably can't discuss company-specific stuff until you actually start). Again, this shows that you're super excited about the team, and it should be perceived as positive energy. Onboarding is so much easier when people like you, so why not start planting those seeds now? For tactics on how to do this, check out this discussion: "How do you network effectively within a company?"