1p3a Question · Oct 2025

Uber L4 Frontend Engineer Interview Experience: Detailed Process

SWE coding Mid

Question Details

Candidate Profile *

Role: Front End Engineer *

Experience: 4.5 Years

Screening Round: Voting Poll Component Design and implement a voting poll UI using a front-end framework (React, Vu

Full Details

Candidate Profile *

Role: Front End Engineer *

Experience: 4.5 Years

Screening Round: Voting Poll Component Design and implement a voting poll UI using a front-end framework (React, Vue, or Angular). *

Core Logic: Display four voting buttons. Clicking a button increments the vote count and dynamically recalculates the percentage distribution. *

Visualization: Each option must feature a colored progress bar that reflects its percentage of total votes. The bars must update in real-time with smooth transitions. *

Enhancements: Include distinct colors for each option, animations, and numeric labels for vote totals or percentages.

Coding Round 1 (DSA): Concurrent Task Queue Implement a task queue in TypeScript that manages concurrency limits. *

Requirements: Execute up to K tasks in parallel; additional tasks must wait in the queue until a slot is available. *

Task Structure: Each task requires a unique ID and must support success and error callbacks. *

Customization: The system must allow a custom executor to define specific execution logic, such as logging, retries, or rate limiting.

Coding Round 2 (UI Coding): Prioritized Modal System Develop a modal component using a UI framework. *

UI Elements: Include primary/secondary action buttons (e.g., Save/Cancel) and an optional close icon. *

Priority Logic: Implement a priority level configuration. The system must automatically close all currently open modals if a new modal with a higher priority is triggered.

**UI

System Design Calendar Application** Design a Google Calendar-style application. *

Authentication: Secure flows for signup, login, and logout. *

Event Management: Capabilities to create, edit, and delete events, as well as accept invitations. Events must store title, time, date, participants, and descriptions. *

Views: Support seamless switching between Month, Week, and Day views.

Manager Round Focus on leadership and collaboration skills based on past professional experience.

About This Question

This is a reported interview question from a uber interview for a swe role (mid level) during the coding round reported in 2025.

It covers the following topics: Os, Concurrency, System Design, Queue, Behavioral, Probability Stats, Stack .