An in-house team delivers the deepest product knowledge. The developers internalise the business domain outsourcing vs in house development a way no external team will match, and that knowledge remains inside the company. The catch shows up as time and rigidity: filling a senior role routinely takes several months, ramping up takes several more weeks, and the cost carries on through the quiet quarters.
Handing a project to a vendor is the arrangement where someone else is accountable for shipping: they staff the team, they manage the plan, and the provider carries the staffing risk. This fits well when the scope is reasonably clear and your side has a decision maker with time for it. It breaks down when the requirements change weekly, because a vendor is not able to guess what the business wants.
Team extension falls in the middle: you add engineers but keep responsibility for delivery yourself. The main advantage is speed — a matching profile is often available almost immediately — and it winds down as quickly as it ramped up. The trade-off is that your engineering managers must have time for code review and planning. If that capacity is missing, you end up paying for hours, not results.
In practice, these models are combined. One durable pattern keeps the critical decisions and the core system inside the vuejs company, while an outside vendor takes on the parts that are bounded and specifiable. The principle is simple enough: retain the parts that are hard to re-learn, and enterprise php contract out what is well understood.
A few questions usually settle it. Start here: is this software central to how you make money, laravel or node js internal plumbing? Next: how long does the work continue — a quarter or a decade? Finally: who answers the phone at two in the morning when it breaks? Work through them with real answers and the right arrangement is normally clear.