No idea. Where are the bottlenecks? What (more precisely than "medium complexity") is in the job design? Lots of Build or Transformer stages? These take longer to compile because of the need to create C++ source code and compile and link that in a way that is callable from the main step (job) flow. These are all additional operations that take compilation time, but have little impact on execution time, which seems to be what you are observing.
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