0110B redirects/day · read-heavy
URL Shortener
Resolve compact links with low latency while creating globally unique aliases.
- Consistent hashing
- Replication
- Failure and retries
System design
walkthroughs.
Move from individual concepts to complete systems. Each walkthrough starts with the request path, makes the important trade-offs explicit, and stress-tests the design with failures.
02Millions of decisions/second
Distributed Rate Limiter
Enforce fair request budgets across many stateless service instances.
- Consistent hashing
- Load shedding
- Replication
03Sub-millisecond reads · high churn
Distributed Cache
Serve hot data quickly while controlling staleness, skew, and stampedes.
- Consistent hashing
- Backpressure
- Failure and retries
04Billions of notifications/day
Notification Platform
Deliver user notifications across channels with preferences, retries, and auditability.
- Delivery semantics
- Backpressure
- Idempotent workflows
05Hundreds of millions of concurrent users
Chat System
Preserve conversation order and deliver messages across connected and offline devices.
- Distributed logs
- Delivery semantics
- Replication
06High-throughput asynchronous work
Distributed Queue
Buffer work durably while coordinating ownership, retries, and poison messages.
- Distributed logs
- Delivery semantics
- Backpressure
07Exabytes · eleven-nines durability target
Object Storage
Store enormous immutable blobs durably with metadata, multipart upload, and repair.
- Replication
- Quorums
- Geo replication
08Tens of milliseconds · read-heavy
Search Autocomplete
Return useful ranked suggestions within a keystroke-scale latency budget.
- LSM trees
- Load shedding
- Replication
09Millions of samples/second
Metrics Platform
Ingest, aggregate, retain, and query high-cardinality time-series data.
- Distributed logs
- LSM trees
- Load shedding
10Elastic data and transaction throughput
Distributed Database
Provide a coherent data model across partitions, replicas, transactions, and failures.
- Quorums
- Replication
- LSM trees
11Gigabytes/second · long retention
Kafka-like Event Platform
Retain ordered event streams for independent consumers and replayable processing.
- Distributed logs
- Delivery semantics
- Backpressure
12Multi-region · low-latency reads and writes
Global Key-Value Store
Serve keys near users while balancing consistency, conflicts, and regional failure.
- Consistent hashing
- Geo replication
- Conflict resolution