Frontend Engineer Interview Questions
Practice 55 real Frontend Engineer interview questions for 2026 — real interview questions from actual interviews with detailed solutions. This collection targets Frontend Engineer interview questions and practical interview preparation across companies currently hiring heavily for frontend talent, including Toma, Uber, Coinbase, and Robinhood. Expect live React/TypeScript coding, component-level problems, and end-to-end tasks that prove you can ship resilient UI under constraints. What makes frontend loops distinctive is their emphasis on product-quality engineering: component design and state management, DOM and asynchronous behavior, and performance/accessibility under load. At Uber interviews you’ll see DOM-manipulation and async-pattern scenarios and large-scale UI performance tradeoffs; Coinbase favors pixel-perfect implementations, robust form/state synchronization, and edge-case handling; Robinhood tests real-time UI consistency and performance at scale; Toma and other early-stage teams focus on rapid prototyping and full-stack integration. Prep by building expressive, testable components, mastering React patterns and TypeScript typings, profiling and accessibility checks, and rehearsing clear trade-off explanations for design decisions.
"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."
Explain React classes, lifecycle, and hooks
This question evaluates understanding of React class and function components, lifecycle phases, Hooks (including state and effect handling), code reus...
Build a Race-Free Memory Card Game in React
Build a Race-Free Memory Card Game in React Implement the interaction logic for a React memory-card game. Every card has a stable ID and a match value...
Present a Previous Project Deep Dive
Prepare a technical deep-dive presentation about a previous project you worked on. Choose a project with enough scope and complexity to support a Staf...
Design Frontend Architecture for Trading UI
Design the frontend architecture for a production trading system UI. Assume the product is a web trading interface with areas such as a market chart, ...
Approximate Pi from Random Points
This question evaluates a candidate's ability to implement array-processing logic and apply probabilistic numerical methods, combining basic geometric...
Field Layout: getOffset and insert
An object's binary layout is defined by an ordered list of fields. Each field has a unique name and a size in bytes. Fields are packed contiguously st...
Deduplicate an Array in Linear Time
This question evaluates a candidate's ability to implement linear-time deduplication of primitive arrays, understand hash-based membership tracking, a...
Implement a recency cache and min-coins DP
This question evaluates data structure design and algorithmic problem-solving skills, focusing on an LRU-style recency cache and a dynamic programming...
Implement a Reusable Dropdown Component
Implement a reusable dropdown component for a production frontend application using a modern framework such as React. The component should support a c...
Filter Matching Subtrees from an N-Ary Tree
Filter Matching Subtrees from an N-Ary Tree Remove every node whose string value contains a given substring. Removing a node also removes its entire d...
Identify the CSS color function
In CSS, which color function accepts red, green, and blue channel values and can also include an optional opacity value?
Build a Stateful Calculator
This question evaluates a candidate's ability to model and manage UI state, handle event-driven input, and implement correct operator chaining in a ca...
Implement an event emitter
This question evaluates understanding of event-driven programming and API design in a frontend environment, specifically the ability to manage event l...
Implement a Constant-Time Random Pool
This question evaluates a candidate's ability to design and implement an efficient data structure supporting average O(1) add, remove, and uniform ran...
Simulate a Rank-Based Tournament
This question evaluates ability to simulate tournament pairing and single-elimination progression using array manipulation and data structures while p...