When you hire a software partner, the engagement model shapes everything that follows: how you budget, how much control you keep, and how the two teams behave when requirements change. There is no universally best model. There is a best fit for your situation.
Here is how we explain the three common models to clients, including the trade-offs that don't make it into sales decks.
Fixed price
You agree a detailed scope, a timeline and a price before work starts. The vendor carries the delivery risk.
Works well when:
- Requirements are clear and unlikely to change.
- The project is small to medium, for example an MVP with a tight feature list.
- You need budget certainty for approval.
Watch out for:
- Time spent writing the specification up front. A vague scope leads to a padded price or painful arguments later.
- Change requests. Every change goes through a formal process, which is healthy but slower.
- Incentives. The vendor is rewarded for doing exactly what was written, not necessarily what turns out to be best.
Time & material
You pay for the actual hours worked, usually invoiced monthly, and you reprioritise as you learn.
Works well when:
- You are building a product and expect to learn from users.
- Scope is uncertain, as in AI and R&D work, integrations with unknown legacy systems, or complex domains.
- You want to be closely involved in sprint planning.
Watch out for:
- Budget discipline. Agree a monthly cap and review burn against progress every sprint.
- Visibility. Insist on working demos, not just timesheets.
Dedicated team
Engineers work full-time on your product, integrated into your processes, tools and rituals. You direct the work; the partner handles hiring, retention and HR.
Works well when:
- You have a long-term roadmap and want stable capacity.
- You already have product and engineering leadership in-house.
- You want to scale faster than local hiring allows.
Watch out for:
- Management load. A dedicated team needs clear priorities from you every week.
- Onboarding. Plan the first month: access, documentation, a buddy on your side.
A quick way to decide
Ask three questions:
- How stable is the scope? Stable points to fixed price. Evolving points to time & material or a dedicated team.
- How long is the horizon? Under six months points to fixed price or T&M. Ongoing points to a dedicated team.
- Who will steer day to day? If the partner will, choose fixed price or T&M. If you will, choose a dedicated team.
You can switch
Many of our clients start with a fixed-price discovery and MVP, move to time & material once real users arrive, and then convert to a dedicated team as the product grows. The right partner should make those transitions easy, keeping the same people and knowledge, rather than locking you into the model you started with.
Not sure which fits your project? Compare the models side by side on our engagement models page, or get a quote and we'll recommend one.