Picking a development partner is a high-stakes decision that’s hard to reverse once a codebase and a working relationship exist. After being on both sides of hundreds of these evaluations, here’s the framework we’d recommend to anyone vetting a partner right now.

Vetting Frameworks That Actually Predict Delivery

Portfolios and case studies tell you what a team has shipped, not how they’ll behave on your project. Ask for a reference client in a similar domain and industry, and ask that reference specifically about what went wrong and how it was handled - every real project has friction, and how a partner responds to it is the signal that matters. A short, paid discovery sprint (one to two weeks) is the single best predictor we know of: it shows you their communication cadence, code quality, and estimation accuracy before you’ve committed to a multi-month engagement.

IP Ownership

This should never be ambiguous. Your contract should state in plain language that you own all code, designs, and derivative work product from day one - not upon final payment, and not with the vendor retaining a license to reuse it. Watch for vendors who build on a proprietary internal framework or boilerplate they won’t hand over; if the code you own can’t run without their private tooling, you don’t fully own it.

SLAs That Protect You After Launch

A development contract that ends at launch leaves you exposed. Look for explicit SLAs covering post-launch bug response times (critical vs. minor severity), uptime commitments if they’re hosting anything, and a defined warranty period for defects introduced during the build. Vague language like "reasonable support" is a red flag - ask for numbers: hours to first response, hours to resolution, and what happens if they’re missed.

Sprint Communication

The best predictor of a healthy engagement isn’t the tech stack - it’s the rhythm of communication. You should expect a working demo at the end of every sprint (not just a status report), a shared backlog you can see and reprioritize in real time, and direct access to the engineers, not just an account manager relaying messages. If a vendor can’t show you a working increment every one to two weeks, you’re buying a black box, not a partnership.

None of these questions are exotic - they’re the ones every experienced CTO ends up asking the hard way, usually on their second vendor. Ask them on the first call instead.