Design paginated list UI and pagination API
Company: DocuSign
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Technical Screen
## Scenario
You are building a web page that displays a list of items (e.g., posts, products, or users). The list must be **paginated**, and users can click page numbers / Next / Prev to navigate.
## Requirements
1. **Frontend UI**
- Display a list of items for the current page.
- Provide pagination controls: page numbers (optional), **Next/Prev**, and current page indicator.
- Handle loading states and empty states.
2. **Backend API** (you may write pseudocode)
- Design an API to fetch a page of results.
- Support stable ordering (e.g., newest-first by `created_at`, tie-break by `id`).
- Include any metadata the UI needs (e.g., whether there is a next page; optionally total count).
3. **Data model**
- Propose a minimal data model for the listed entity.
- Describe database indexing needed for efficient pagination.
4. **Corner cases to consider**
- Items inserted/deleted while the user is paging.
- Very large datasets (cannot scan all rows).
- Out-of-range pages, empty results.
- Changing sort/filter while paging.
## Deliverables
- High-level architecture for frontend ↔ API ↔ database.
- API request/response design.
- Data model + indexes.
- Discussion of tradeoffs (e.g., offset vs cursor pagination).
Quick Answer: This question evaluates skills in designing paginated user interfaces and pagination APIs, covering frontend-backend integration, stable ordering, data modeling, database indexing, and handling consistency and edge cases such as concurrent inserts/deletes and out-of-range pages.