Engagement models
Three ways to structure an engagement, and which one fits depends on how well-defined the scope is before work starts — not on project size.
Fixed Price
A defined scope, a defined price, agreed before work starts.
Fits when: The requirements are clear enough to specify upfront — a defined module, a well-scoped integration, or an MVP with a fixed feature list.
Time & Material
Billed for the time and work actually done, on an agreed rate, with regular reporting.
Fits when: The scope is expected to change — an evolving product, a build where priorities shift after early user feedback, or work planned in short iterations.
Retainer
An ongoing arrangement for continuous work — ongoing maintenance, a dedicated team, or recurring support.
Fits when: There's no single fixed-scope project — just ongoing product work, or you need engineering capacity for however long the work continues.