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
Cloud Engineer
•
Coding
•
medium
Implement a function that takes an IPv4 address string and a CIDR block string (e.g., '192.168.1.5', '192.168.1.0/24') and returns a boolean indicating if the IP belongs to the CIDR block.
#Networking
#Bit Manipulation
#Python
#Go
Cloud Engineer
•
Technical
•
medium
Walk me through the lifecycle of a DNS query when a user types x.com, focusing specifically on how global load balancing and Anycast routing are involved.
#DNS
#Load Balancing
#Anycast
#BGP
Cloud Engineer
•
Technical
•
easy
Explain the difference between an Application Load Balancer (ALB) and a Network Load Balancer (NLB). When would you explicitly choose an NLB for a service at X?
#Load Balancing
#AWS
#OSI Model
Cloud Engineer
•
Technical
•
hard
Explain BGP routing. How does X use BGP to announce IP prefixes for its global CDN network?
#BGP
#CDN
#Routing
#Networking
DevOps Engineer
•
Technical
•
medium
A user complains that images on X are loading slowly in a specific geographic region (e.g., Southeast Asia). How do you troubleshoot this?
#CDN
#DNS
#Latency
#BGP
#Traceroute
DevOps Engineer
•
Technical
•
medium
How does DNS resolution work? Walk me through the steps, and explain how you would configure DNS failover for a global service.
#DNS
#Failover
#Routing
DevOps Engineer
•
Technical
•
hard
Explain the TCP 3-way handshake. How would you tune TCP parameters on a Linux kernel to handle millions of high-throughput, low-latency connections?
#TCP/IP
#Linux Kernel
#Sysctl
#Networking
Full Stack Engineer
•
Technical
•
medium
Describe the differences between Server-Sent Events (SSE) and WebSockets. Which would you choose for streaming new tweets to the client and why?
#WebSockets
#SSE
#HTTP
Software Engineer
•
Technical
•
medium
Explain how a reverse proxy works. How does it help in load balancing and securing X's API traffic?
#Load Balancing
#Security
#Architecture
Software Engineer
•
Technical
•
easy
Describe the differences between TCP and UDP. Why might X use UDP for its Spaces live audio feature?
#Protocols
#Networking
#Streaming
Difficulty Radar
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Senior EngineerFocuses on core competencies, system constraints, and clear communication.
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