One mistake I repeatedly see is founders evaluating MVP developers mainly through:
Price
Timeline
Framework experience
Portfolio screenshots
Those things matter, but they do not reveal how the developer will make product and architecture decisions.
I think these questions are more useful:
What would you remove from the MVP?
What technical foundations would you refuse to postpone?
How would you handle multi-tenant authorization?
What happens when a payment or external API fails?
Who controls GitHub, hosting and third-party accounts?
How often will I receive a working demonstration?
What is excluded from the estimate?
What support exists after launch?
A developer who challenges unnecessary scope may be more valuable than someone who immediately agrees to build everything.
The same applies to architecture. Early products often need a clean monolith and reliable deployment—not a collection of microservices created before the product has users.
I wrote a longer guide based on these points, but I am interested in the founder perspective:
What question helped you identify a good—or bad—development partner?
Full guide: