Got an offer from Airbnb for a senior mobile role (iOS) in January and negotiated it a little, so here's the honest version of what worked.
Starting offer: Base: $200k RSU: $230k over 4 years Bonus target: 15% No signing
After negotiation: Base: $205k RSU: $270k over 4 years Bonus target: 15% (unchanged) Signing: $25k
So I moved base $5k, equity $40k, and added a signing bonus. Not a massive swing but meaningful over the 4-year window.
What worked: I had a real competing offer, an iOS role at another company with slightly higher base but no RSU (pre-Series B startup). I was transparent with the recruiter that I was genuinely weighing them. She didn't lowball me on that offer being "not comparable" which I appreciated. The competing offer gave her something to bring back to the comp team.
On the RSU bump: I just asked. Specifically said something like "base is close but the equity makes more of a difference over the vest period. Can you see if there's flexibility there?" They came back with the $40k bump within 2 days.
The signing bonus I asked for last, after everything else was settled. Framed it as bridging unvested equity I was leaving behind at my current company. That framing was useful because it gave them a justification in their internal system.
What didn't work: Asking to move bonus target. They said that's fixed by level and non-negotiable. Maybe true, maybe just harder to move. Didn't push.
Asking for front-loading the RSU vest. They said no.
One thing I'd do differently: I asked for everything in one email and might have had more success going one lever at a time. You lose the ability to declare victory and move on when you batch the requests.