Architecture

Cheatsheet: repository classes, unit-of-work, generic base repo, service-layer separation.

Practical EDA: when async events fit, outbox patterns, idempotency, dead letters, and an honest take on EDA’s costs vs benefits.

RTB system design. Latency budget breakdown, candidate generation, ranking, fraud, billing, and the operational realities of a sub-100ms decisioning pipeline.

End-to-end design for sending newsletters / transactional email at scale. Sender reputation, bounce / complaint handling, suppression lists, throttling per provider, and the patterns from real ESPs.

Leaderboards and live counters at scale. Redis sorted sets, counter sharding for hot keys, eventual consistency tradeoffs, and the production realities.

When gRPC actually wins for service-to-service traffic. Performance numbers, the ergonomics gap, debugging tradeoffs, and how to mix gRPC inside with REST at the edge.

End-to-end design for a collaborative editing system. Operational Transformation vs CRDTs, presence, cursors, persistence, conflict resolution, and the realities at scale.

How to design a photo-sharing platform: media upload pipeline, image processing, feeds (timelines), follow graph, search, and the operational realities.

Why most products should start with a modular monolith, when microservices earn their cost, the modular monolith pattern, and the modern split decision.

End-to-end notification system design. Channels, templates, preferences, fan-out, batching, deduplication, observability, and the patterns from production.