An in-house team buys you the deepest product knowledge. The offshore node.js developers learn the business domain over time, and that accumulated context stays inside the company. The cost shows up as time and rigidity: recruiting a strong engineer takes months, onboarding adds several more weeks, and the payroll continues regardless of workload.
Full outsourcing is the arrangement where an external team owns the outcome: the provider staffs the project, the partner manages the process, and software development pricing they carry the risk of missing the date. The model works when the outcome can be described and you have someone who can make decisions quickly. It fails when nobody on your side owns the product, since the provider is not able to guess what the business wants.
Team extension falls in the middle: you rent capacity but keep responsibility for delivery on your side. The main advantage is speed — a matching profile can join in weeks rather than months — and the commitment ends when the work does. The catch remains that your engineering managers need the capacity to direct the work. Without strong internal leadership, you are paying for effort with no owner.
In practice, these models are combined. A frequent arrangement puts the architecture and the core domain in-house, while an external team handles peaks, well-defined modules or platform work. The principle holds: hold on to the parts that are hard to re-learn, end to end project development and outsource anything a competent team can specify and deliver.
A few questions usually settle it. To begin with: is the system the product itself, or a cost centre? Then: for how long will the work last — one project or a permanent roadmap? Last: who answers the phone at two in the morning when it breaks? Answer these three honestly and the right arrangement usually chooses itself.