I've been testing tilemaker with larger extracts to see how RAM usage is with larger extracts

Doing a linear fit gives a RAM requirement for the current planet of 290GB. Sizing for 3 years growth I'd add 40% to the current planet size and a more complex conversion would require more RAM, which I'd put at a 50% growth, for a total estimated RAM need of 600 GB in 3 years. With AWS instances with 1 and 2TB of RAM this isn't impossible, but is expensive, and I'd be reluctant to recommend planning on doing Germany (2.9GB) or Canada (2.1GB) on a machine with 32GB of RAM.

The next steps depend on the intended direction of tilemaker, and what limitations and tradeoffs are acceptable.

The build of tilemaker I used wasn't multithreaded and I didn't get a good fit for conversion times, so I'm not going to focus on that.