Hi!
I use a custom-built combination of Teams channels, SharePoint Lists, and the Planner app.
Teams: Used to organize relevant files and communications by having a different channel for each major project or overall topic. Under the General channel, there are folders for smaller items/projects that don't require a whole channel.
SharePoint List: Used as a dashboard for new project requests/assignments to be submitted and tracked by everyone, internal and external. Different views are used to help with this.
Planner: Used internally to keep track of workload. It's set up in a Kanban board, and the buckets are loosely based on the Agile PM framework.
I used Power Automate to build workflows that connect all of these so they can better interact with each other. Like, when a new request or assignment is submitted on SharePoint, it creates a Planner card and assigns it, and updates to the Planner card also directly update the SharePoint list.
It took a while to develop and is still a work in progress in some ways while we keep refining things, but the overall structure works very well for us and I loved learning new skills with building automated workflows and List dashboards. I also love how everything has been customized to meet our needs.