My project has 17k lines of Scala code (no whitespace). I don't have a SSD. It takes 10 minutes to perform SBT Assembly from a cold start, 40 seconds afterwards

My project has 17k lines of Scala code (no whitespace). I don't have a SSD. It takes 10 minutes to perform SBT Assembly from a cold start, 40 seconds afterwards. And about 1-3 seconds to compile and run locally within IDEA.