How many months does it take you to build this?

How many months does it take your team of X developers to build the system described below?

Several micro-services that makeup a Dropbox-like system with no GUI.

1. Service that does basic CRUD on files stored on disk via HTTP GET/POST.
2. Service that manages auth/ownership of files in #1.
3. Service that runs cron jobs to cleanup deleted files in #1.
4. Service that backs up files in #1.

Asking to get some perspective after learning how long it’s taking a team of 8 my client recently hired a few months ago. Should be delivered by early 2022.