Vatra

The core challenge was geospatial querying at scale. Events are queryable by bounding box, radius, or city polygon using PostGIS on Postgres 17, with spatial indexes keeping query times flat as data grows.

Event moderation runs asynchronously through BullMQ: submissions drop into a queue, and a Telegram bot serves as the admin interface — moderators approve or reject directly from chat, no dashboard. Logto handles OIDC for end users; Redis backs caching and the queue. Everything runs in Docker and deploys via GitHub Actions.

Built solo, backend and frontend in parallel, from an empty repo.