Cool stuff! We actually built a similar system to analyze the NYC taxi dataset (or any other geospatial dataset). We use the (PostgreSQL wire protocol compliant) HyPerSpace database in the backend [1]. Let us know if you're ever experiencing performance problems with PostGIS.
[1] https://db.in.tum.de/downloads/publications/hyperspace.pdf
Very nice visualization and write-up! The tech details are pretty interesting. In particular, noting the back-end was done up in PostgREST. I've been itching for a project to kick the tires on that for a while.
Any more you can add about the experience of "writing" the back-end in PostgREST if you're hanging out in this thread, Billy?
Can you share what parts of PostgREST way of doing things you found nice and what parts are lacking?
Sure - PostgREST provides a RESTful API endpoint for any PostgreSQL database. It's kinda magic.
It's an interesting beast: it has almost no configuration at all, you just point it to one database schema, and it then uses the postgres permissions system to decide what tables & views to expose, and who gets to see them.
The only part of it that was a little tricky was creating multiple database users for anonymous views off the internet vs. internal staff who would want to do more than just select some rows.