Notes from https://www.hellointerview.com/learn/system-design/in-a-hurry/core-concepts

• Need to sketch out APIs that clients use to interact with the system in interview

• Default to REST for 90% of cases

  REST API

  • Maps resources to URLs and uses HTTPS methods to manipulate them

• Common mistake

  • Spending too much time designing APIs
  • Sketch out 4-5 key endpoints in couple mins (no longer than 10 mins)

• Concepts worth mentioning

  • Need pagination when returning large result sets

  • Cursor-based works better for real-time data where new items get added frequently

  • Offset-based is fine for most cases

  • For authentication, use JWT tokens for user sessions and API kets for service-to-service calls

    JWT Tokens

    API keys

  • If the system can be hammered by bots or abuse, mention rate limiting

  • Don’t go deeper on any of these unless the interviewer specifically asks

Notes from https://www.hellointerview.com/learn/system-design/core-concepts/api-design