An in-house team gives you long-term retention of knowledge. The developers learn the business domain over time, and that knowledge remains in the building. The catch comes in the form of time and rigidity: filling a senior role is slow, getting someone productive adds several more weeks, and the cost keeps running regardless of workload.
Project outsourcing implies the vendor owns delivery: they staff the team, the partner manages the plan, and they absorb the risk of missing the date. This fits well when the scope is reasonably clear and there is a decision maker with time for it. It breaks down when there which is better flutter or react native no one to answer questions, as the provider will not invent your business rules.
Team extension falls in the middle: you add engineers but keep the management in-house. It moves quickly — a matching profile can start almost immediately — and it winds down as quickly as it ramped up. The condition is that your own leads have to have time for code review and planning. Without that, you are paying for hours, not results.
In the real world, companies blend them. A common pattern puts the architecture and the core domain inside the company, while an outside vendor handles peaks, well-defined modules or platform work. The rule is easy to state: keep what defines your product, and contract out what is well understood.
Three questions usually settle it. To begin with: is this edtech software development the product itself, or a supporting tool? Next: how long will you need this capacity — months or years? Third: who will maintain it in two years? Work through them with real answers and the model is normally clear.