The truth is many product managers are hired exclusively for their domain experience, and I do think that there a few products where domain experience is truly essential. However, this is an exception than the rule.

Marty Cagan in his book says that it can be dangerous for a product management to have too much domain experience. According to him people who have spent a long time building their mastery over one domain often fall into another product management trap: they believe they can speak for the target customer, and that they are more like their target customer than they really are. The product manager needs to constantly revisit assumptions about the domain and the customers. It’s not impossible for people with deep domain expertise to do this, but they have to work harder at it to remain open-minded to new developments and options.

This is not to say that you do not need good domain experience in order to do a good job with your product–in fact understanding your product domain is absolutely essential, and not superficial knowledge either. However, strong product managers can come up to speed on most new product domains very quickly if they approach the education process aggressively. In general it takes one one to three months to come up to speed on a domain that you haven’t worked on before, to the point where you feel confident charting a product strategy. Some people can probably learn faster, and others might take a little longer.

However, skills vary for products in different industry: leading enterprise products versus infrastructure, versus consumer services, versus consumer electronics.

Overall, about 80% of the skills and talents of a product manager are applicable across the different types of products.

Most valuable experience is not what you learn about some product domain or technology, but rather what you have learnt about the process of creating great products, leading a product team, and managing growth. It’s also about what you have learnt about yourself and how to improve the next time.

Technologies change so fast that product managers must be skilled at quickly learning new technologies and solving problems in new domains. When you interview prospective product managers,  don’t look for what they already know, but for each of their products, what did they need to learn, how long did it take them, and how did they apply that knowledge?

Last week I had a chance to meet Adrienne Tan, CEO of BrainMates, a popular product management consultancy based out of Australia. I posed the same question her and this is what she had to say. “As a product management consultancy we work with varied domains everyday. Product Management as a practice is domain agnostic. The principles are so robust and unfailing that they apply to every industry sphere and benefit it. Product Management is no rocket science.  All it needs is practice.”