Valko_Milev:

but for the others the framework is too complex for me to make any meaningful contribution.In this case I will need some one to guide me.


Have you already tried to interact with the team on these specific tickets?
E.g. you could start to discuss your doubts or some rought implementation details there before writing a PR.
For some specific subcomponent you can always try to open a thread here to have some tecnhical clarification (using help_dev and contributing tags).
For large changes we require to submit and discuss an RFC but probably a preliminar general discussion on the forum it is strongly suggested:

  
      

      TensorFlow
  

  
    

The TensorFlow RFC process 1