Dear all,

I am going to apply to some of the major MBA programs in the US and have an issue with the choice of the “right” recommender.

My first recommendation will be from my current supervisor from a company where I work full-time. This is clear.

As I have cofounded an NGO for a couple of years ago, I would like to get my second recommendation from the other cofounder. In fact, he is the core cofounder, more senior to me in any dimensions (age, position: Executive Officer, while I am his deputy). Still, he is not my relative or something like that. 

Thus questions arise.

1. Will admissions committees really trust my second recommendation? (I mean the conflict of interest due to opinion from other cofounder)
2. Is it enough to explain that the co-founder is the chief executive and I am his deputy and another co-founder, so that there is no doubt?
3. We are a non-profit organization and the title co-founder does not play such a role as in the business environment. So, I can simply avoid mention the fact that that I am a co-founder at all.

Many thanks in advance!

There's no single answer to this, but you are grappling with the right questions. You'll need to check the targeted school's requirements because they will differ. In practice, when you have read a few hundred of these letters, it's very easy to see that most are just bland, overly positive and not highly useful. A recommendation letter that takes a supportive but helpful approach towards your goals and development needs will be taken more seriously. 

Admissions teams will have no trouble understanding what a co-founder is. However, a co-founder can found something and then walk away. You need to be able to explain what you did, how that fit into the division of labour and how you were held accountable.