What is more important, domain or functional skills in a Product Manager?

I face this questions umpteen number of times as hire Technical Product Managers & Product Managers. As always, there are people (Colleagues, Reference Providers, and Interviewers etc.) who tell me how certain candidate will be a good fit as a Product Manager. And since there are many panel members who interview the prospective Product Management candidate I always hear things like ‘this person would suite well as he/she has lot of domain experience’ or ‘this person won’t be able to do the job as his/her domain experience is not strong’.

I don’t know why but I never understand why people think on those lines. I always feel that Product Manager needs to be a ‘package’ (as shown in the picture below) rather than lump of domain knowledge or few strong skills. Of course among all the required skills, domain (business area) & functional (product management) will typically come out as major requirements but in my opinion having them/not having them shouldn’t dictate the effectiveness of Product Manager.

PM Skills


In my opinion, how much of domain or functional knowledge is important depends a whole lot on the product in question, stage it is in its lifecycle, the industry it serves, and customer problem it solves. If you are supplying in niche business areas then the product manager must be at least understand the business. But if you are supplier of generic products then domain experience should not be the dictator as domain can be quickly learned by a good product management professional.

When hiring domain expert as product manager you are assuming that domain expert can ‘represent the customer’. With all due respect to their domain expertise, generally I have seen that, domain experts will have strong opinions and hence may not be bring in the ‘openness’ required to represent the needs of customer, which is one of the most important attribute of a good Product Manager.

My experience suggests that if you have a good product manager, it is easier for them to gain domain knowledge (most can do that within matter of months), than a domain expert trying to learn how to become a product manager. The main reason for such thing to happen is because domain experience is gained over years of experience (typically 10+ years) and by the time you become domain expert your learning ability to learn product management skills (which are mostly soft skills) will significantly reduce (just plain human physiology & psychology J).

But this is how I think, what do you think?