All 62 questions

  1. How would you design rate limiting for a public API?

    Asked in 6 of 377 interviews · last asked Oct 16 · Design · Senior

    Show answer

    I would limit requests per API key or user at the API gateway, with IP limits for anonymous traffic. A token bucket allows short bursts while limiting the average rate. Across servers, I would keep shared state in Redis and update it atomically. Rejected requests get HTTP 429 with Retry-After.

    • Set limits by customer plan and endpoint cost.
    • Use atomic updates so concurrent requests cannot bypass the limit.
    • IP limits can affect unrelated users sharing one network.
    • Decide whether to allow or block requests if the rate limiter fails.

    What the interviewer checks: The interviewer checks whether you can enforce fair limits across servers while handling bursts and failures.

    Other ways it was asked
    • “How would you implement a rate limiter for APIs?”
    • “What is API rate limiting, and how would you implement it?”
    • “Imagine you're building an API in Node.js that needs to handle rate limiting for different users. How would you design that solution?”

  2. How do offset pagination and cursor pagination differ?

    Asked in 4 of 377 interviews · last asked Oct 14 · Concept · Mid-level

    Show answer

    Offset pagination skips a set number of rows, then returns a page. Cursor pagination uses a token to continue from a known position in the result order. Offset makes page jumps easy but can slow down at large offsets. Cursor pagination is usually faster for deep pages, but arbitrary page jumps are harder.

    • Both need a stable sort order, with a unique field to break ties.
    • Inserts or deletes can make offset pagination skip or repeat items between requests.
    • Position-based cursors handle those shifts better, but do not guarantee an unchanged view of the data.
    • Efficient cursor queries need indexes that support the sort order.

    What the interviewer checks: The interviewer checks whether you understand navigation, performance, and what happens when data changes between requests.

    Other ways it was asked
    • “What is the difference between using an offset and a cursor for database pagination?”
    • “Explain the trade-offs between offset pagination and cursor pagination.”
    • “What is the difference between page-based pagination and cursor-based pagination?”

  3. What is pagination?

    Asked in 3 of 377 interviews · last asked Sep 18 · Concept · Junior

    Other ways it was asked
    • “What do you mean by pagination?”
    • “What is pagination, and when would you use it?”

  4. How would you design an API to efficiently retrieve data from millions of database records?

    Asked in 2 of 377 interviews · last asked Sep 30 · Design · Senior

    Other ways it was asked
    • “How would you design an API to handle millions of records?”
    • “How would you design pagination for an API that needs to handle millions of records?”
    • “How would you efficiently handle an API that needs to return data from 10,000,000 student records in a Postgres database?”

  5. What do you mean by rate limiting?

    Asked in 2 of 377 interviews · last asked Sep 12 · Concept · Junior

    Other ways it was asked
    • “What is rate limiting?”

  6. How can you reduce API response time?

    Asked in 2 of 377 interviews · last asked Oct 7 · Scenario · Mid-level

    Other ways it was asked
    • “How would you reduce average API response time by 30%?”

  7. Where would you implement rate limiting—within the API endpoints or in another component?

    Asked once · last asked Feb 11 · Design · Mid-level

  8. What rate-limiting patterns are available, and how can they be set up?

    Asked once · last asked Feb 11 · Concept · Senior

  9. Do GraphQL and REST require different API optimization strategies?

    Asked once · last asked Feb 23 · Concept · Senior

  10. When you're creating a REST API, how do you ensure it efficiently handles high traffic and scales as needed?

    Asked once · last asked Feb 25 · Design · Senior

  11. How would you optimize transaction-history retrieval if the system has been running for 20 years but the account is only one year old?

    Asked once · last asked Mar 5 · Scenario · Senior

  12. How can you implement pagination in Spring Boot?

    Asked once · last asked Mar 10 · Tooling · Mid-level

  13. How would you design a rate limiter for an API allowing 50 requests per second per user across multiple stateless application servers? What components and data stores would you use, and how would you enforce consistency?

    Asked once · last asked Mar 16 · Design · Senior

  14. When redesigning a REST API to handle higher traffic, what database query challenges might arise, and how would you address them?

    Asked once · last asked Mar 25 · Scenario · Senior

  15. How can rate limits on metasearch platforms affect an integration, and how would you handle them?

    Asked once · last asked Apr 27 · Scenario · Mid-level

  16. How would you design an API endpoint that returns paginated results from a large dataset? How would you address performance and user experience concerns?

    Asked once · last asked May 8 · Design · Mid-level

  17. Where does an API gateway fit, and is it more suitable for monolithic or microservice-based systems?

    Asked once · last asked May 22 · Concept · Senior

  18. How would you improve a Telegram bot's reliability when a currency API enforces rate limits?

    Asked once · last asked Jun 6 · Scenario · Mid-level

  19. When ensuring that the UI correctly uses data fields from a back-end API, how do you typically make sure performance isn't compromised?

    Asked once · last asked Jul 11 · Scenario · Mid-level

  20. What do the search term, page, page size, and cancellation token parameters do in a repository method?

    Asked once · last asked Jul 20 · Concept · Mid-level

  21. How does a repository retrieve users when given a search term, page number, and page size instead of a specific user ID or email?

    Asked once · last asked Jul 20 · Concept · Mid-level

  22. When you don't know the image dimensions upfront and want to avoid a full download, how do you design the API/client flow to get dimensions efficiently and still handle failures or slow networks?

    Asked once · last asked Jul 20 · Design · Senior

  23. Create an endpoint for a global rate limiter service that accepts a request containing a user ID, name, and timestamp.

    Asked once · last asked Jul 22 · Write code · Senior

  24. How would you fix a slow API when many requests have the same inputs and return the same output?

    Asked once · last asked Jul 27 · Scenario · Mid-level

  25. What concerns would you consider when constructing cache keys for an application-level API cache?

    Asked once · last asked Jul 27 · Scenario · Mid-level

  26. You are defining a new high-performance gRPC microservice with large datasets and huge unary payloads. What strategies and best practices would you use for protobuf messages and RPC protocols?

    Asked once · last asked Aug 5 · Design · Senior

  27. How would you design an API integration to transfer three billion rows of daily production data to an insurance information center?

    Asked once · last asked Aug 22 · Design · Senior

  28. How would you design an AI integration and an API processing architecture for one million incoming records?

    Asked once · last asked Aug 25 · Design · Senior

  29. How would you implement filtering bookmarks by their stored tags?

    Asked once · last asked Aug 28 · Scenario · Mid-level

  30. How would you page through a very large dataset efficiently?

    Asked once · last asked Sep 1 · Concept · Mid-level

  31. How does a file get uploaded from a frontend to a backend?

    Asked once · last asked Sep 8 · Design · Mid-level

  32. How does a 10 GB file get uploaded to the backend?

    Asked once · last asked Sep 8 · Design · Mid-level

  33. What information do you need to implement pagination at scale and render it in a user interface?

    Asked once · last asked Sep 9 · Scenario · Mid-level

  34. How would you design an API to return a very large list of employees?

    Asked once · last asked Sep 10 · Design · Senior

  35. What kind of SQL query would a paginated API use to retrieve results?

    Asked once · last asked Sep 10 · Concept · Mid-level

  36. How would you optimize a large-list API if 1,000 users accessed it at the same time?

    Asked once · last asked Sep 10 · Design · Senior

  37. Besides rate limiting, how would you manage high demand for a large-list API while still allowing users to query it?

    Asked once · last asked Sep 10 · Design · Senior

  38. How would you design APIs in a full-stack application to scale under increased load?

    Asked once · last asked Sep 17 · Design · Senior

  39. If an external API suddenly cuts its rate limit in half, what would you change first in an export process?

    Asked once · last asked Sep 18 · Scenario · Senior

  40. How would you return thousands of database records to a user interface without overwhelming it?

    Asked once · last asked Sep 19 · Scenario · Mid-level

  41. How would you prevent records from being skipped or retrieved twice when records are added or updated during pagination?

    Asked once · last asked Sep 21 · Scenario · Senior

  42. How would you design data access for a search feature, including tables, indexes, query strategy, and consistent pagination as data changes?

    Asked once · last asked Sep 22 · Design · Senior

  43. When using keyset pagination with relevance and creation-time sort keys, how would you keep ordering deterministic when relevance scores tie or change between requests?

    Asked once · last asked Sep 22 · Design · Senior

  44. How do you configure and manage an API Gateway for a microservices application?

    Asked once · last asked Sep 23 · Tooling · Senior

  45. How would you design or optimize a challenging RESTful API to address performance and scaling concerns?

    Asked once · last asked Sep 23 · Behavioral · Mid-level

    Other ways it was asked
    • “Can you share an example of a challenging RESTful API you designed or optimized, and how you handled performance or scaling concerns there?”

  46. How would you process 50,000 records faster without overwhelming the external API?

    Asked once · last asked Sep 25 · Scenario · Senior

  47. How would you implement date-based filtering in an application?

    Asked once · last asked Sep 27 · Scenario · Mid-level

  48. How would you design the API and backend system for uploading a video reel larger than 250 MB?

    Asked once · last asked Sep 29 · Design · Senior

  49. How would you retrieve nearby vehicles for a map-based mobile app?

    Asked once · last asked Sep 29 · Scenario · Mid-level

  50. How would you improve a backend API that takes about a minute to import hundreds of thousands of records from a CSV file?

    Asked once · last asked Oct 1 · Scenario · Senior

    Other ways it was asked
    • “How would you address timeouts when a backend API imports hundreds of thousands of records from a CSV file?”

  51. How would you design an architecture to send WhatsApp messages to 10,000 leads under rate limits and track delivery in real time?

    Asked once · last asked Oct 1 · Design · Senior

  52. How would you build a rate limiter shared across multiple API instances?

    Asked once · last asked Oct 5 · Design · Mid-level

  53. How would you address a frontend that sends requests every second instead of every five minutes, making backend operations too costly?

    Asked once · last asked Oct 6 · Scenario · Senior

  54. How can a server control requests when a frontend sends them too frequently?

    Asked once · last asked Oct 6 · Scenario · Senior

  55. How would you design an API for uploading and storing photos?

    Asked once · last asked Oct 7 · Design · Mid-level

    Other ways it was asked
    • “How would you store uploaded photos as files, and how would the API handle them?”

  56. How would you architect product search functionality, including the API call?

    Asked once · last asked Oct 8 · Design · Mid-level

  57. How would you implement infinite scroll from the frontend perspective, and what parameters need to be sent to the backend API?

    Asked once · last asked Oct 8 · Design · Mid-level

  58. Design a rate limiter for an LLM API.

    Asked once · last asked Oct 21 · Design · Senior

  59. How would you diagnose and optimize a slow API query for a leaderboard, and what could cause tasks to block while waiting for an API response?

    Asked once · last asked Oct 22 · Scenario · Mid-level

  60. What does the search term parameter do when fetching users from a repository?

    Asked once · last asked Jul 20 · Concept · Junior

  61. Why do we need an API gateway?

    Asked once · last asked Sep 4 · Concept · Mid-level

  62. What is the purpose of a REST API gateway?

    Asked once · last asked Oct 1 · Concept · Mid-level

More REST API interview questions

How this list is made

Every question here was asked by a real interviewer in a real job interview that a candidate ran MeetAssist in. After the call, the interviewer's questions are pulled from the transcript. Practice sessions, tests, exams and anything that was not a job interview are dropped.

Questions are rewritten so they make sense on their own: names of people, employers and clients are removed, and speech-to-text mistakes are fixed. Small talk, logistics and questions about one candidate's own résumé are left out. Rephrasings of the same question are merged, and the count is the number of different interviews it came up in.

The interviews come from candidates who use MeetAssist, so they lean towards software, data and AI roles: the shares describe these interviews, not every REST API interview. Answers to the most asked questions are written and checked by an editor; a "common mistake" is shown only when reviews of real answers in these interviews show it, with the count.

377 interviews, 243 candidates, Jan 2026 to Oct 2026. Updated every month with new interviews.