Roku Interview Questions
Practice 14 real interview questions from Roku. Covers Analytics & Experimentation, Behavioral & Leadership, Coding & Algorithms, System Design. For roles including Data Scientist, Backend Engineer, Software Engineer.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Implement ad filtering and concurrent cache
Two coding tasks were described. 1. Ad candidate filtering: You are given a list of ad candidates. Each ad has ad_id, company, topic, and score. Retur...
Design a high-throughput ad exchange
Design an ad exchange that handles roughly 175,000 bid requests per second. Publishers send impression opportunities to the platform, and demand-side ...
Explain concurrency and distributed fundamentals
A backend fundamentals round covered the following topics: 1. Multithreading in Java: Suppose multiple threads update a shared counter and a shared ma...
Compute longest common subsequence length
Problem You are given two strings s and t. A subsequence of a string is obtained by deleting zero or more characters without changing the order of the...
Design a video-on-demand streaming service
Scenario Design a large-scale video-on-demand (VOD) streaming service similar to a major streaming platform. Users should be able to: - Sign in and br...
Explain and quantify bias-variance tradeoff
Bias–Variance Tradeoff: Intuition, Derivation, and Practical Tuning Task Explain the bias–variance tradeoff at two levels and connect it to model tuni...
Measure speaker impact without A/B testing
Your company launched an optional smart speaker on 2025-01-10. Adoption is voluntary; 6% of existing app users purchase within 60 days, and you cannot...
Write SQL for profit, growth, retention
Write ANSI-SQL (PostgreSQL preferred) for the tasks below. Assume all timestamps are UTC and that "today" = 2025-09-01. Schema: - products(product_id ...
Analyze Profit Decline: Data Collection and Hypothesis Testing
Coffee Shop Profit Drop Diagnostics Scenario You manage a coffee shop and notice profits have declined over a recent period. Task Outline a systematic...
Demonstrate cross-functional collaboration and influence
Behavioral Prompt — Cross-Functional Collaboration (STAR) Provide a specific example of cross-functional collaboration with a Product Manager (PM) and...
Diagnose coffee-shop profit decline
You run a single-location coffee shop. In August 2025, profit dropped 18% vs July while transactions fell 4% and average check rose 2%. You have these...
Explain Bias-Variance Trade-off Simply for Stakeholders
Scenario You are in a technical phone screen for a Data Scientist role. The interviewer asks you to communicate a core modeling concept in plain langu...
Measure Speaker's Impact Using Propensity Score Matching
Causal Impact of Optional Device Ownership on Engagement (Observational Design) Scenario A new, optional smart speaker is released. Some users purchas...
Describe Aligning Goals with Cross-Functional Teams
Behavioral: Cross-Functional Collaboration (Data Scientist Phone Screen) Context You are interviewing for a Data Scientist role where you partner with...