at what point do you get written offers?

That's all you know how to do and think a tech company needs you?

You can shop around verbal offers. Some might want proof. But most not. You will get a written offer generally after u have verbally accepted. For some good tips on negotiating: https://haseebq.com/my-ten-rules-for-negotiating-a-job-offer/

In my experience these companies will not issue a written offer until either you’ve agreed on a number or they’ve reached their ‘final’ offer. Before that most recruiters will do it verbally because there are a bunch of approval steps to both approve comp and issue the written offer. It’s pretty easy to negotiate based on verbal offers, especially if you e been transparent that you’re interviewing elsewhere from the start. In my case they did not ask for written verification, but if an offer is way out of band they may request proof. If only do that to get to a ‘final’ offer, not early in negotiations.

You get a verbal offer but do not accept it until you see it in writing. Best practices is that you get a written offer so you can review it and all the benefits, package, etc. at that point you can formally accept. If you get a verbal you could tell the other companies but as already stated, if it’s outrageous or you risk increasing it to seek more, the company may say “congrats on that offer, bye ” and you are out. so be truthful for best outcome. FAANG recruiters are aware of market pay.