Raft or Paxos are used for partition tolerance and there are implementations that you can use. Maybe you will spend more time but you will learn something useful.

You will easily spend 10-20h for "normal" coding interview.

  5h to refresh basic algorithms BFS, DFS, sorts, Trees.
  2h for hackerrank challenge from clueless HR person
  3h for another preparation before whiteboarding on site
  1h whiteboarding before any design question is asked

A benefit of "normal" interview process is that you chase multiple opportunities and your prep time will compound for better results.