How can I gracefully leave my job?

Congrats on the offer! (and sorry about how bad your current team was I guess)

I mean, it seems your goal here is to just... lie? I think my series around communication can help with that alongside the other things mentioned in the question: Alex's Guide To Effective Communication

How do I gracefully communicate that I'm leaving the company? What do I say to my manager when I tell him?

Tell them that you really appreciate everything they did for you, but you found a better opportunity you couldn't pass up.

What should I say to my teammates?

Same thing as above. And if they were genuinely good to you, tell them that.

Who should I connect with before leaving?

Honestly, pretty much everybody probably? LinkedIn connections are cheap. We talk more about this here: [Masterclass] How To Build Deep Relationships Quickly In Tech

How should I handle the exit interview?

It depends on whether you want to help the company:

1. If so, be honest (but communicate with empathy of course like outlined in my communication series)
2. If not, just lie and say it was great but this new opportunity was too good

What can I do to leave in a manner where I'm welcome to come in case things go south at the new place?

Feign extreme gratitude towards your entire team and make them feel awesome. 😂

Adding on to that, your performance is a big factor as well (and this is something you can't change anymore as you're on your way out). For example, Meta labels every departing employee as "regretful" or "non-regretful" exit:

• Regretful means that the company was sorry to see you go and these folks are generally high performers
• Non-regretful means that the company doesn't care that this person is leaving and they were probably a very average to low performer

You mentioned that you were a strong performer, so there's a good chance you'll be in the "regretful" bucket for your company (if it exists). All the more reason to make the effort to preserve bridges (and maybe even try to extend them).

Keep it simple and don't overthink it. In all my previous jobs, I didn't let how I felt about any of those places / people affect what I do in terms of ensuring there is a good transition and clean handoff. Maintain a high professional standard when doing this and trust me, people notice and remember, especially if it's done poorly.

In terms of what feedback to give, you'll know best who will take the feedback in a constructive manner vs. those that see it as offensive, which will lead to an unproductive outcome. I usually refrain from going too deep into the weeds, especially when feeling strong emotions (e.g. resentment for current place/people and/or excitement for new job). I've had some success with giving feedback to certain people I keep in touch with after I've left the job for a few months (those are usually worthwhile connection and good investments of time to offer feedback).

Bound the time and energy you spend on the above. Don't linger on it for too long, you've got an exciting journey awaiting you in your new role. Good luck!