By default, Unity doesn't cache assets in your project, which means that Unity Editor startup times and build times can be slow because Unity doesn't reuse processing artifacts across projects or teams.

To speed up import and build times, you can install the Unity Accelerator cache server, which keeps copies of a team's imported assets to help reduce development iteration time. Unity Accelerator uses the asset import pipeline to coordinate asset sharing when your team is working on the same local network so that you don’t need to reimport portions of your project.

Solo developers can also install Unity Accelerator and get the benefit of faster build times and Editor startup times if you're reusing assets across projects or regularly performing clean builds.