What is the Ideal Product Team Size?
Another method for deciding how many product managers a company needs is to base it on the number of engineers working on the company’s products. In 2007, Marty Cagan of the Silicon Valley Product Group said you need one product manager for every 6-10 developers, and today the “seven, plus or minus two” mentality is fairly pervasive (which makes sense given the Agile model).
This is really a Goldilocks-style conundrum: if the ratio is too small, the developers won’t be able to code fast enough to keep the product manager busy, and they’ll just be adding items to an ever-increasing backlog; and if the ratio is too large the product manager may not be providing enough details and interaction with the engineering team to properly guide its work.