Choosing a supplier is a hard decision to reverse: you find out it was wrong two months in, when switching is expensive. The questions below reveal more than any portfolio.
Who writes the code?
Projects are often sold by one team and delivered by another. Ask for names, and who reviews before delivery. We put a named human on every delivery — but ask everyone, not just us.
Who owns the code?
You should. Require repository access from day one, not at handover: a repo you only see at the end hides the quality of the work until you have no leverage left.
How is quality reviewed?
Ask about tests, review, and what happens when a defect appears after launch. "We test everything" is not an answer; ask for a real defect and how it was handled.
Why fixed price is a warning sign
A lump sum with no breakdown moves risk to you, not away from you: anything unstated becomes "out of scope" later. Ask for the lines — and see what actually drives the cost.
Start with a small task
The best test is a short, paid, scoped piece of work before any large commitment. You see the code, the responsiveness and how change is handled — for far less than discovering it six months in.