The Medium article says to visit the site for the standards.[1] That yields: MAX.gov Application Unavailable If you are seeing this message and it is not Sunday 2AM-8AM ET then please contact MAX Support by clicking here. If you’re trying to access MAX Community, please use our snapshot site: MAX Snapshot Community Site "MAX.gov" appears to be some kind of in-house cloud service for the Federal government. [1] https:…
It's not fully in house. The idea is to centralize management of services (both in-house and external) for budgeting reasons, since MAX is part of GSA which is part of the OMB (Office of Management and Budget).
Btw, GSA and OMB aren't connected the way you describe. They just happen to be the respective parent agencies of 18F and USDS-HQ. Here's a tree.
POTUS
├── GSA
│ └── 18F
└── OMB
├── USDS-HQ
└── MAX