The way you contract a software project shapes everything from budget certainty to product quality. Here's how to pick the model that fits.
Choosing a development partner is only half the decision. The engagement model you agree on decides who carries the risk, how you handle change, and how much control you have over the team.
Fixed price: certainty for well-defined scope
A fixed-price project works best when requirements are stable and can be written down in detail: a marketing website, a clearly specified integration, or phase one of a product with a validated prototype.
- Pros: predictable budget and timeline, minimal management overhead.
- Cons: change requests add cost and friction, and vendors pad estimates to cover uncertainty.
Time & materials: flexibility for evolving products
With time and materials (T&M) you pay for the effort actually spent. It suits products where you expect to learn as you go, such as new SaaS platforms, MVPs and AI features where the right approach emerges through experiments.
- Pros: you can re-prioritise every sprint, with no change-request overhead.
- Cons: requires active product ownership and trust, built through transparent reporting.
Dedicated team: an extension of your company
A dedicated team works exclusively on your product for months or years, following your roadmap and rituals. It's ideal when you need to scale engineering capacity without the hiring overhead.
Our recommendation
Many successful projects combine models: a fixed-price discovery phase to define scope and architecture, followed by T&M or a dedicated team for delivery. Whatever you choose, insist on working software every sprint. It's the single best indicator that a project is on track.