Building your own team delivers the deepest product knowledge. The developers internalise your customers and your data model over time, and that accumulated context stays in the building. The cost is time and rigidity: recruiting a strong engineer is slow, getting someone productive adds several more weeks, and the payroll keeps running through the quiet quarters.
Full outsourcing software development process is the arrangement where an external team owns the outcome: the provider staffs the roles, they manage the day-to-day work, and they carry the staffing risk. The model works when the work is a defined project and you have an available product owner. It works badly when there is no one to answer questions, as an external team is not able to invent your business rules.
Staff augmentation falls in the middle: you rent capacity while keeping the management on your side. The main advantage is speed — a matching profile is often available far sooner than a new hire — and it scales down as easily as it scales up. The trade-off remains that your own leads need time for code review and planning. Without strong internal leadership, the result is paying for hours, not results.
Most of the time, these models are combined. A common pattern holds architecture, swift development company product decisions and core domain code in-house, while an external team takes on the parts that are bounded and specifiable. The principle is easy to state: retain what defines your product, and outsource what is well understood.
A few questions generally decide the matter. To begin with: is this real estate software development the product itself, or internal plumbing? Next: for how long will you need this capacity — one project or a permanent roadmap? Third: who will maintain it in two years? Answer those honestly and the appropriate option becomes obvious.