When It Is Time to Scale the Product Team
The Current Size of the Team Has Become Tight for the Product
It’s quite a run-of-the-mill and natural reason to grow your development crew. You have built software that has found its audience. A number of customers have enrolled for the product and now you need to scope up the project to meet the soaring customers’ demand and to reach the next level.
The reason for the expansion is that you don't have enough human resources to roll out the product. The current team is too busy or does not possess enough competence to size up the product. WhatsApp and Wase followed exactly the same path to scale the product team.
It is worth noting that it is critical to timely pinpoint the need for team expansion and not to put it off until a better day. Delays can come at a high cost. For example, your place will be taken by a competitor who has implemented user demand faster.
The Idea Stretches Beyond One Product
Your ideas go beyond one product and there is a need to develop side projects. In other words, it's time to move from product to platform.
The Facebook platform was once a product. Now Facebook is represented by the web and mobile Facebook applications, Messenger, Ads Manager, and Pages Manager. Each of the products is handled by a separate team and product manager even though they are all working for good of the single platform.
The same growth can take place with your product. So if you decide to move to a platform product and develop one or more backing applications, that's a reason to employ more product developers and generally a whole separate team to create and maintain a sub-product.
The Marketing Campaign Is Way Too Cool
Perhaps you have passionate marketers that overdid it and promoted the app slightly too much. You end up with a situation where user expectations don't match the actual app and the app itself doesn't solve the problem as advertised.
In such a situation, it is necessary to improve the app so that it meets the expectations of users. If this is beyond the capabilities of the current team, then you need to scale the software development team.
The Project Exceeds the Human Resources
As for outsourced software development companies, in addition to the above-mentioned reasons for expanding the software development team in projects, they may also face another quite evident dilemma - a lack of staff to cover all projects.
This problem can be caused by too fast growth in the number of projects or by the lack of skills and experience of current employees to implement customer requests. Scaling the software development team can help solve these problems.

These are the most day-to-day reasons for hire more product developers. Though you may have your own ones, one thing remains important - to not miss the moment when expanding the product team is required.