| Who you talk to weekly | The person writing the code. | An account manager relaying to whoever is free on the bench. | A partner at the pitch, then a delivery manager and a changing team. | A senior tech lead who knows the code, plus a recorded demo every week. |
| What you are buying | One person's hours. | Hours from a pool, usually billed per head. | A programme, with governance, change management and on-site presence. | A fixed bid after discovery, or a monthly team with a named lead. |
| If a key person leaves | The work stops until you find someone new. | A replacement arrives; your context often does not. | Continuity holds, and you pay for the layers that provide it. | Decision records, runbooks and a repository in your account let the next engineer start from documents. |
| Best fit | One bounded job in a single discipline. | Tightly specified tickets reviewed by your own senior engineers. | Multi-year transformation with a large bench and heavy procurement. | A defined build or roadmap needing engineering and design owned end to end, with Eastern Time overlap. |
| Does not fit | Projects needing backend, design, QA and delivery management in parallel. | Buyers with no engineer of their own to check the output. | Budgets where the overhead would outweigh the build. | Scopes below one senior engineer plus one designer, ideas without validated demand, or teams that need every engineer in a US office. |