Presenting to Engineers
Presenting a design at the level of mechanism, including the alternatives rejected and the parts you are still unsure about.
This audience is evaluating whether the design is correct and buildable, so they need the things an executive summary deliberately removes: component boundaries and why they fall there, the data model, the failure modes and what happens in each, and the alternatives you considered and why they lost.
The counter-intuitive part is the last item on the list: say what you are unsure about. Presenting a design as settled when it is not invites the room to find the flaw during review and lose confidence in the whole thing. Presenting the open questions honestly recruits them into solving those questions, which is both better engineering and better politics.
Expect and welcome challenge. A design review where nobody pushes back has not reviewed anything, and the silence usually means the audience has stopped believing the outcome is influenceable.