Signals model state, RxJS models events over time — when to use each, performance numbers, and the interop pattern that uses both at the right boundary.
The MLOps playbook: deploying models (REST/batch/streaming), versioning + registry + CI/CD, drift monitoring, cloud strategies, and a full end-to-end app.
A system design walkthrough of YouTube: resumable upload, the transcoding pipeline, blob storage, CDN delivery, and adaptive bitrate streaming at scale.
A system design walkthrough of Uber: geospatial indexing (geohash/quadtree/H3), finding nearby drivers, rider matching, live location, and surge pricing.