I don't think Haskell/FP is a solution either... Even if it allows some beautiful straightforward parallelization in Spark for typical cases, more advanced case

I don't think Haskell/FP is a solution either... Even if it allows some beautiful straightforward parallelization in Spark for typical cases, more advanced cases become convoluted, require explicit caching, and decrease performance significantly, unless some nasty hacks are involved (resembling cut operator in Prolog). I guess bleeding edge will be always difficult and one should not restrict their choices to a single paradigm.