GSA, Digital Analytics Program: https://analytics.usa.gov/
Huge amounts of data about how government websites are used including: locations (cities, countries), languages, referral sources, media sources, devices, browsers, OS, website destination, and top file accesses.
Treasury, Government Spending Explorer: https://www.usaspending.gov/explorer/budget_function
Really thorough breakdown of government spending from 2017 onward, with per month, per quarter, and year spending totals by budget function and agency. Divable categories so you can look at the $1,400,000,000,000 in National Defense spending, and actually find out a little about where it all goes to each year.
Edit: Here's their Github and 1200 repositories: https://github.com/orgs/18F/repositories
If I had enough money to hire them, I'd snap their employees up quickly.