Warner Bros Discovery

Large Enterprises

Warner Bros. Discovery is a multinational mass media and entertainment conglomerate formed by the merger of WarnerMedia and Discovery, Inc. It produces and distributes film, television, and streaming content through brands like Warner Bros., HBO, CNN, and the Max streaming service.

5 interview notes · updated Jul 2026

Warner Bros Discovery·Software Engineer·Technical Phone Screen

Jul 2026

Did a technical screen for a Software Engineer role at Warner Bros Discovery. Two coding problems, nothing crazy hard but the second one had a follow-up I wasn't fully prepared for.

Implement left and right rotation of an array by k positions, where k can exceed the array length.
Given a CSV string, find all occurrences of a keyword and return the row, column, and character position within the cell for each match.

“Felt pretty solid on this one.”

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Warner Bros Discovery·Software Engineer·Onsite - System Design / Architecture

Jun 2026

System design round at Warner Bros Discovery for what seemed like a senior backend or platform engineering role. The problem was a targeted ad delivery system with A/B testing baked in, which sounds manageable until you start pulling on the real-time selection and metrics collection threads at the same time.

Design a targeted ad delivery system that supports A/B testing, handles high traffic, selects ads in real time, and collects metrics for analysis.

“I started with the ad selection service and worked outward, which in retrospect was a mistake.”

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Warner Bros Discovery·Software Engineer·Technical Phone Screen

Jun 2026

Got a coding problem at Warner Bros Discovery that started simple but had a real sting in the tail. CSV parsing with keyword search, then they asked you to scale it up for multiple keywords, which is where things got interesting.

Given a CSV file and a keyword, find all occurrences of that keyword and return the line numbers and character positions. Then extend your solution to handle multiple keywords efficiently.

“The first part felt manageable.”

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Warner Bros Discovery·Software Engineer·Technical Phone Screen

Jun 2026

Got a coding question at Warner Bros Discovery that looked straightforward on the surface but had a subtle twist baked in. The in-place constraint is what makes it interesting.

Given an array, rotate it left by k positions and then rotate it back right by k positions. Both operations must be done in-place using O(1) extra space.

“The left-then-right thing felt redundant at first and I almost said so out loud.”

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Warner Bros Discovery·Software Engineer·Onsite - System Design / Architecture

Apr 2026

System design round at Warner Bros Discovery for a software engineer role. The whole thing was centered on ad serving infrastructure, which I wasn't expecting to go as deep on experimentation as it did.

Design an ad content delivery system that selects and serves ads to users and supports A/B testing and experimentation.
How would you handle targeting logic (country, device, placement, user segments) efficiently at high throughput?
Walk me through your event logging pipeline for impressions and clicks, and how you'd separate what needs to be real-time versus eventually consistent.
How would you design the A/B testing assignment and exposure logging to ensure deterministic bucketing and avoid experiment contamination?
What delivery controls would you implement, and how do you handle frequency capping and deduplication under high concurrency?
What are the main failure modes in this system and how would you design around them?

“This is a beast of a question.”

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