Ownership of hard problems
Did you personally do the work? Elon Musk's signature interview question is: tell me about some of the most difficult problems you worked on and how you solved them. It is designed to separate the person who personally solved a problem, and can go deep on the constraints and tradeoffs, from someone who was merely on the team.
In the onsite you present a project where you made the decisions, and interviewers push on the specifics. The person who actually solved it can explain the constraints, the tradeoffs, and why a given value or approach was chosen. Saying I do not remember why I picked X on your own design decision is close to an instant rejection, because it reveals you did not own the call.
Write first-person bullets that name the decision and the tradeoff you made, each tied to a quantified outcome. Make it clear which call was yours and why you made it, so the ownership is isolatable from the team.
Chose a regenerative over ablative cooling design for a test nozzle to cut mass 18 percent, accepting higher manufacturing complexity; validated on 12 hot-fire tests with zero burn-through.
We-heavy bullets that credit the team with no isolatable contribution. If every line reads we built or the team shipped, an interviewer cannot tell what you personally decided, and the hardest-problem question will expose it.
Worked with the team to develop and deliver a range of propulsion and avionics improvements across several vehicle programs.
Ex-SpaceX engineer breakdown (snubber.ai), corroborated by CNBC and Fast Company reporting on Musk's interview question.