Design a Payment System — Stripe-Style Architecture in 2026
Production-grade payment system design. Idempotency keys, double-entry ledger, async fulfillment, webhook handling, PCI scope, fraud rails, and the patterns Stripe-style products use.
Architecture
Design a Search System — Elasticsearch, OpenSearch, and Postgres FTS in 2026
End-to-end search system design. Engine choice, indexing pipeline, ranking, hybrid search with embeddings, multi-tenancy, and the operational realities.
Designing Webhooks That Don't Ruin Anyone's Day in 2026
How to design webhooks producers AND consumers can rely on. Signing, retries, idempotency, ordering, observability, and the patterns from real production webhook systems.
Multi-Tenancy Patterns for SaaS in 2026 — Shared, Pooled, or Per-Tenant
Three multi-tenant patterns: shared (tenant_id everywhere), pooled (schema-per-tenant), per-tenant DB. The decision matrix by scale, isolation, compliance, and cost.
Event Sourcing and CQRS in 2026 — When the Pattern Pays Off
Event sourcing and CQRS without the religion. Where they earn their cost, why most apps don’t need them, and the pragmatic mid-paths.
API Design Patterns 2026 — Resource-Oriented vs Action-Oriented vs RPC
Three API shapes you’ll see in 2026: resource-oriented (REST), action-oriented, and RPC. The strengths of each, when hybrids work, and the design choices that age well.
LLM Cost Optimization in 2026 — Tactics That Cut Bills 50–90%
Production-tested LLM cost optimization tactics. Prompt caching, model routing, semantic caching, batching, fine-tuning small models, output bounds, and the architecture decisions that make the cost line item bearable.
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.
Design YouTube / Video Streaming — A System Design Walkthrough
A complete system design for a YouTube-style platform. Upload, transcoding to HLS/DASH variants, storage at petabyte scale, CDN delivery, adaptive bitrate, recommendations, and the operational realities.