Add storage via good USB hub or use a multi-bay storage box later on. The have built-in hubs. E.g. Terramaster or OWC Mercury Elite Pro.

For the highest possible resource utilization and security support beyond Apple’s, you could try [installing Linux](wiki.debian.org/…/Early-2015-13-inch] and using Docker containers for everything. You should be able to run quite a few services.

The next best option resource-wise is to run a large Linux VM and docker containers inside it. The Docker for Mac setup does exactly that. This is how we solved running a complex and resource hungry tech stack locally for development at a past workplace.

Then come running services in multiple VMs.