Hiring in-house delivers long-term retention of knowledge. The developers internalise your customers and your data model in a way no external team will match, and this context sits inside the company. The catch shows up as a long ramp-up and fixed costs: hiring well takes months, getting someone productive takes several more weeks, and the payroll carries on whether the roadmap is full or empty.
Project outsourcing is the arrangement where an external team owns the outcome: they staff the roles, the partner manages the plan, microservices vs monolith and the provider carries the staffing risk. This fits well when the outcome can be described and there is an available product owner. It works badly when there is no one to answer questions, since an external team will not invent your business rules.
Staff augmentation sits between the two: you bring in developers while keeping the management yourself. The main advantage is speed — a suitable engineer can join almost immediately — and it scales down as easily as it scales up. The trade-off remains that your own leads need the capacity to direct the work. If that capacity is missing, you are paying hourly for uncoordinated work.
In the real world, these models are combined. A common pattern holds architecture, product decisions and core domain code with permanent staff, while an external team takes on the parts that are bounded and specifiable. The line holds: hold on to what differentiates you, and outsource anything a competent team can specify and deliver.
A few questions resolve most of these debates. Start here: is this software development outsourcing saudi arabia central to how you make money, or a supporting tool? Second: over what horizon will you need this capacity — months or years? Third: who answers the phone at two in the morning when it breaks? Answer those honestly and the appropriate option usually chooses itself.