I'm preparing the resume for a big agency, they want the resume in their own format, however their format does not allow to add hobbyst/opensource experience (just jobs). Since I have almost 10 years in C++ opensource development is it ok mentioning it anyway? As I understand, from the interview call there was some pressure for hire me as Java developer, even if they gave me a C++ online quiz and have open C++ positions in the company.
I developed over small 10 C++ projects on my own, plus various contributions to several OpenSource projects. It happened to me few times also in helping a friend to resolve some difficult task in C/C++ (friends that are regularly employed and working with C++). It looks to me that hobbyst experience is totally discarded by interviewers, and it is a pity since I did a lot of nice projects.