| Engagement structure | Sprint 0 scoping plus a milestone-billed build. One fixed-scope engagement. | Per-engineer hourly placement. You own the deliverable. | Sales-led discovery, then a multi-team build proposal. | Fixed-price build off a brief, no working discovery. | You drive the tool. No team, no engagement. |
| Scope before the build | Two to four weeks of working engineering and product time, six concrete deliverables. | You write the scope. The marketplace places engineers against it. | A discovery deck and a SOW, typically one to two weeks. | A brief from you, then a fixed-price quote. Often missing acceptance criteria. | You scope it yourself in the tool as you go. |
| Team shape | Two to four people: full-time engineers paired with the fractional roles the build actually needs. Lean by design. | One engineer at a time. You assemble the team. | Five to fifteen across multiple practice areas. Partner ladder. | Variable. Often shared across clients. | You are the team. |
| AI fluency | Baseline for every engineer. AI tooling in the build loop comes standard. | Per-individual. You filter for it. | Practice-level, often priced as a premium specialism. | Variable. Often retrofit onto a non-AI process. | AI is the tool itself, not the engineering around it. |
| Pricing shape | Sprint 0 fixed fee, build milestone-billed against acceptance. | Hourly markup per engineer. | Time-and-materials or fixed bid, priced for $200M+ enterprise budgets. | Hourly or fixed-price. Cost-led positioning. | Per-seat subscription. Production-grade work is your problem. |
| Best fit | Startups shipping a new product, or companies commissioning a defined AI product for internal or external use, where milestone-billed economics fit the budget shape. | Teams who want point-and-shoot capacity and will own the build management. | Multi-team initiatives at enterprise budgets. | Cost-led builds where price beats engineering quality. | Founders prototyping solo before the codebase needs production-grade architecture. |
| Where it loses | Teams wanting hourly billing. Multi-month enterprise procurement. Engagements that need point-and-shoot staffing rather than a fixed-scope build. | Sustained team stability. Partnership layer. | Lean-team scope sizes that do not fit enterprise budgets. | Engineering quality. Codebase extensibility after the agency exits. | Production-grade architecture. Integration with existing systems. Codebases that real engineering teams will extend. |