High-Level Design
System Design › High-Level DesignDesign an E-commerce Platform (High-Level Design)
High-level design of an e-commerce platform (Amazon/Flipkart): decompose into catalog, search, cart, inventory, order and payment services; optimise the read-heavy browse path with CDN, caching and a search index; and solve the overselling problem with reserve-before-charge, idempotent payments and a Saga.
System Design › High-Level DesignDesign a Leaderboard (High-Level Design)
High-level design of a real-time leaderboard: a Redis sorted set giving O(log n) score updates, top-K and exact-rank queries, backed by a durable DB, with time-scoped boards, sharding by score range and approximate rank to scale to tens of millions of players.
System Design › High-Level DesignDesign a Distributed Job Scheduler (High-Level Design)
High-level design of a distributed job scheduler (cron-as-a-service): jobs indexed by nextRunTime, a leader scheduler that enqueues due jobs, stateless workers, and the reliability story — leader election, at-least-once + idempotency, visibility timeouts, retries and sharding.
System Design › High-Level DesignDesign an Ad Click Aggregator (High-Level Design)
High-level design of an ad-click aggregator: ingest millions of click events into Kafka, aggregate over event-time windows in a stream processor, serve rolled-up counts from a fast OLAP store, and reconcile with a nightly batch for billing-grade accuracy.
System Design › High-Level DesignDesign Google Maps (High-Level Design)
High-level design of Google Maps: pre-rendered map tiles served from a CDN, the road network as a weighted graph with precomputed shortcuts for routing, and live traffic/ETA built from aggregated user location pings via a streaming pipeline.
System Design › High-Level DesignDesign Instagram (High-Level Design)
High-level design of Instagram: photos in blob storage behind a CDN, lightweight metadata and follow graph in a database, feeds via fan-out on write with a hybrid pull path for celebrities, plus async like/comment counters.
System Design › High-Level DesignDesign Ticketmaster / BookMyShow — System Design
Design a ticket booking system where the core challenge is concurrency: no double-booking under a flash-sale stampede. The reservation pattern, pessimistic vs optimistic locking, strong consistency, and virtual waiting rooms.
System Design › High-Level DesignDesign Dropbox / Google Drive (File Sync) — System Design
Design a file sync and storage service end to end: chunking files into blocks, content-hash deduplication, block-level delta sync (only upload what changed), metadata vs block storage, notifications, conflicts, and versioning.
System Design › High-Level DesignDesign a Payment System (Stripe) — System Design
Design a payment system where correctness is everything: idempotency keys to prevent double charges, the PSP flow and webhooks, an immutable double-entry ledger, strong consistency, reconciliation, and PCI tokenization.