Compensate for lack of experience?

We are a junior dev team (4 people) working on a prototype in javascript (node/angular/mongodb).

We often have troubles with the testability and modularity of our code base (on top of that we're based in distant time zones). This is something that an experienced mentor/advisor would help with a lot. However, experienced team leaders willing to mentor young teams are hard to find.

If someone had this problem before, how did you overcome this? How do you find or motivate mentors to help you at this stage?