An ATS can help any business that is currently hiring or is planning to hire in the future.
However, it can be beneficial for companies who are looking to grow their team significantly. This is due to the fact that when hiring multiple roles at once, without an ATS, the hiring manager's inbox is sure to get messy. Whereas when using an ATS, applications can more easily be collected and sorted.
Using an ATS is also recommended for smaller businesses without a dedicated recruitment or HR team. The ATS can help to simplify the hiring process, by collecting applications and allowing easier collaboration between those involved in hiring.