01Ask who owns the result
Code, infrastructure accounts, domains and data should be in your name from the start. A partner who resists this is selling you dependency.
Get the handover terms in writing before the first invoice, not at the end when leverage has moved.
02Probe the failure stories
Every real delivery team has a project that slipped. The useful question is what they changed afterwards — that answer reveals more than any case study.
Ask to speak to a client from a finished engagement, not only the flagship one.
03Check how they scope
A partner who quotes a fixed price for a vague brief is either padding heavily or planning to argue later. Look for a discovery step that produces a written scope you could hand to someone else.
Insist on knowing what is explicitly out of scope. That list is where budget disputes come from.
04Agree what happens after launch
Support hours, response times, who holds on-call and how changes are priced should be settled before go-live. Software without an owner degrades quickly.