Twitter / X
Real-time social platform with petabyte-scale data and ML ranking systems.
4 Rounds
~14 Days
Hard
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Frontend Engineer
•
Coding
•
medium
Build a Tweet character counter function that takes a string and returns the count, but URLs should always count as exactly 23 characters regardless of their actual length.
#String Manipulation
#Regex
#Edge Cases
Frontend Engineer
•
Coding
•
medium
Implement a custom `EventEmitter` class in JavaScript with `on`, `off`, `emit`, and `once` methods.
#Design Patterns
#Data Structures
#Closures
Frontend Engineer
•
Coding
•
medium
Implement `Promise.all()` from scratch. It should take an array of promises and return a single promise that resolves with an array of results, or rejects immediately if any promise rejects.
#Asynchronous Programming
#Promises
#Error Handling
Frontend Engineer
•
Coding
•
medium
Write a function to deeply merge two JavaScript objects. If a key contains an array in both objects, concatenate them. If it's an object, merge recursively.
#Recursion
#Object Manipulation
#Type Checking
Frontend Engineer
•
Coding
•
medium
Implement a generic `memoize` function. Add a feature where the memoized values expire after a given Time To Live (TTL) in milliseconds.
#Caching
#Closures
#Time Complexity
Frontend Engineer
•
Coding
•
medium
Write a function that parses a raw tweet string, finds all @handles and #hashtags, and returns an array of objects representing the text segments and their types for rendering.
#Parsing
#Regex
#Data Transformation
Frontend Engineer
•
Coding
•
medium
Implement a rate limiter function in JavaScript. It should take a function, a limit (number of calls), and a time window, and drop any calls that exceed the limit within the window.
#Algorithms
#Time Complexity
#Closures
Frontend Engineer
•
Coding
•
easy
Write a polyfill for `Array.prototype.reduce`.
#Prototypes
#Array Methods
#Functional Programming
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
SimulateUnwritten Rules
Think Out Loud
Always explain your thought process before writing code or drawing architecture.