Hiring in-house delivers long-term retention of knowledge. The developers learn the business domain in a way no external team will match, software development company in moscow and that accumulated context remains with you. The price is slow hiring and fixed overhead: recruiting a strong engineer takes months, onboarding adds several more weeks, and the cost carries on through the quiet quarters.
Handing a project to a vendor means an external team owns the outcome: they staff the team, the partner manages the plan, and the provider carries the risk of missing the date. This fits well when the work is a defined project and your side has someone who can make decisions quickly. It works badly when nobody on your side owns the product, because a vendor cannot fill that gap for you.
Team extension falls in the middle: difference between rest and graphql you bring in developers while keeping the planning and the management in-house. The main advantage is speed — the right specialist can join almost immediately — and it scales down as easily as it scales up. The trade-off remains that your engineering managers have to have the bandwidth to manage them. If that capacity is missing, you are paying for effort with no owner.
Most of the time, the models mix. A common pattern puts the architecture and the core domain in-house, while a partner covers the parts that are bounded and specifiable. The line holds: llm application development keep the parts that are hard to re-learn, and delegate the well-trodden work.
Three questions resolve most of these debates. To begin with: is this software central to how you make money, or a supporting tool? Second: how long will the work last — one project or a permanent roadmap? Finally: who owns it once the vendor top aso agencies leaves? Answer these three honestly and the model usually chooses itself.