An in-house team buys you long-term retention of knowledge. The developers absorb your customers and your data model in a way no external team will match, and this context stays with you. The price comes in the form of time and rigidity: hiring well is slow, ramping up adds several more weeks, and the payroll continues regardless of workload.
Project outsourcing implies someone else is accountable for shipping: they staff the project, the provider manages the plan, and they carry the staffing risk. This works well when the scope is reasonably clear and your side has a decision maker with time for aso services it. It breaks down when the requirements change weekly, since an external team will not invent your business rules.
Staff augmentation is the middle option: you bring in go developers for hire while keeping responsibility for delivery in-house. It is fast — a matching profile can join far sooner than a new hire — and it outsourcing development scales down as easily as it scales up. The trade-off remains that your own leads have to have time for code review and planning. Without strong internal leadership, software development process the result is paying for effort with no owner.
Most of the time, companies blend them. A common pattern keeps architecture, product decisions and core domain code with permanent staff, while an external team handles the parts that are bounded and specifiable. The principle is simple enough: keep what differentiates you, and contract out what is well understood.
Three questions generally decide the matter. Start here: is the system a core competitive asset, or a cost centre? Then: how long will you need this capacity — a quarter or a decade? Third: who owns it once the vendor leaves? Answer those honestly and the right arrangement is normally clear.