System design (HLD, LLD and architecture)
API Design (REST, gRPC, GraphQL, Webhooks)
The planned outline of 19 modules. Lessons are written, run and reviewed before they are published.
Planned outline
- Module 1
Foundations: APIs as contracts
Coming soon - Module 2
Resources, URLs and representations
Coming soon - Module 3
HTTP semantics: methods, status codes and conditional requests
Coming soon - Module 4
Errors and validation
Coming soon - Module 5
Reliability in the contract: idempotency, retries and timeouts
Coming soon - Module 6
Collections: pagination, filtering and bulk work
Coming soon - Module 7
Long-running work, large files and sync
Coming soon - Module 8
Versioning and evolution
Coming soon - Module 9
Authentication, authorisation and abuse
Coming soon - Module 10
Rate limits, quotas and gateways
Coming soon - Module 11
Describing APIs with OpenAPI 3.2
Coming soon - Module 12
Testing and operating APIs
Coming soon - Module 13
Webhooks and event-driven APIs
Coming soon - Module 14
Real-time APIs
Coming soon - Module 15
gRPC and Protocol Buffers
Coming soon - Module 16
GraphQL
Coming soon - Module 17
Other styles, AI-era APIs and choosing a style
Coming soon - Module 18
API design interviews and reviews
Coming soon - Module 19
Case studies: designing whole APIs
Coming soon
Related tools
OpenAPI / Swagger Editor & Validator Paste an API description: see every problem by line, the API reference and curl commands. REST API Tester (Online API Client) A Postman-style API client in this tab — requests go straight from you to the API. HTTP Status Codes Reference Every HTTP status code explained: what it means, why you got it and how to fix it. JSON Schema Validator Check JSON against a schema and get every error with its path, line and a clear fix. JWT Decoder Read any JWT and check its signature — without sending the token anywhere.
Official documentation
- www.rfc-editor.org/rfc/rfc9110.html (rfc-editor.org)
- www.rfc-editor.org/rfc/rfc9457.html (rfc-editor.org)
- spec.openapis.org/oas/latest.html (spec.openapis.org)
- grpc.io/docs (grpc.io)
- datatracker.ietf.org/doc/draft-ietf-httpapi-ratelimit-headers (datatracker.ietf.org)
More in System design (HLD, LLD and architecture)
- System Design (High-Level Design) (coming soon)
- Low-Level Design (Object-Oriented Design) (coming soon)
- Design Patterns (GoF and modern) (coming soon)
- Concurrency & Multithreading (coming soon)
- All System design tracks
- How we make lessons