Distributed Transactions in 2026 — Sagas, 2PC, and What Actually Works
Practical distributed transactions: why 2PC rarely fits, sagas (orchestration vs choreography), outbox + CDC, idempotency, and the operational tradeoffs.
Distributed Systems
Design a URL Shortener — From One Box to a Billion Redirects
URL shortener design: base62 keys, ID generation strategies, caching, analytics fanout, and how to handle a viral link gracefully.
Design a Distributed Counter — From 100 to 100M Updates per Second
Distributed counter at every scale. Postgres single-row up to ~10k updates/sec. Redis sharded counters up to ~1M. Async aggregation patterns for billions.
Designing a Multi-Region SaaS in 2026 — Patterns That Actually Work
Multi-region patterns: per-tenant region pinning, read replicas everywhere, write to home region, eventual consistency on the global plane, and the operational realities.
Distributed Locks in 2026 — Redis, Postgres, Zookeeper
Designing distributed locks. Redlock vs Redis SET NX, Postgres advisory locks, ZooKeeper / etcd, fencing tokens, and the patterns that prevent split-brain.
Design a Distributed Cache — Memcached Successor Patterns in 2026
End-to-end design for a distributed cache. Consistent hashing, replication, eviction policies, hot keys, and the operational realities.
Design a Distributed Rate Limiter at Scale — Beyond Single-Redis in 2026
When single-Redis stops being enough. Sharded rate limiters, hybrid local/global counters, sliding-window approximations, fairness, and the patterns from CDN-scale services.
Circuit Breakers, Bulkheads, and Backpressure — Resilience Patterns for 2026
The resilience patterns every backend engineer should reach for: circuit breakers, bulkheads, backpressure, deadlines, jittered retries, and the production tradeoffs.
Design a Distributed Task Queue — Production Patterns That Scale
End-to-end system design for a distributed task queue. Durability, ordering, retries, dedup, fairness, scheduling, dead-letter handling, and the implementation patterns on Postgres, Redis, NATS, or Kafka.
Design Uber — Location Tracking, Dispatch, and Surge in System Design
A complete system design for a ride-hailing platform. Geohash / S2 / H3 indexing, real-time location ingestion, dispatch matching algorithms, ETA prediction, surge pricing, and the operational realities at scale.