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Interview questions from top companies, mapped to the exact round they show up in. Prep for what you will actually face.

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Online AssessmentDSA / CodingMachine CodingLow-Level Design

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The Loop aggregates publicly shared interview experiences and curated commonly-asked questions, each labeled with its source. Not affiliated with any company listed.

CC BY-NC 4.0 · © 2026

← Optum

Senior Frontend at Optum

FrontendSeniorOffer◆ Commonly asked· 2023

A senior frontend loop. Pragmatic questions — more real-world than pure puzzles.

The loop · 6 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • Construct binary tree from preorder and inorder traversal.
    SeniorMedium◆ Commonly asked
    #tree#recursion
    PracticeLeetCode↗GeeksforGeeks↗
  • Sliding window maximum.
    SeniorHard◆ Commonly asked
    #deque#sliding-window
    PracticeLeetCode↗GeeksforGeeks↗
  • Jump game.
    SeniorMedium◆ Commonly asked
    #greedy#dp
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 2 questions

Machine Coding

Build a working component or service under time pressure.

  • Build a to-do app with filters and localStorage persistence.
    SeniorEasy◆ Commonly asked
    #react#state
    PracticeGeeksforGeeks↗Search↗
  • Build a kanban board with drag and drop.
    SeniorHard◆ Commonly asked
    #react#dnd
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 2 questions

System Design

High-level architecture of a large-scale system.

  • Design a search autocomplete at Google scale.
    SeniorHard◆ Commonly asked
    #trie#ranking#cache
    PracticeGeeksforGeeks↗Search↗
  • Design a scalable frontend for an infinite feed (data, caching, rendering).
    SeniorHard◆ Commonly asked
    #frontend#virtualization#cache
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • Explain how CSS-in-JS differs from utility CSS.
    SeniorEasy◆ Commonly asked
    #css
    PracticeGeeksforGeeks↗Search↗
  • Explain memoization: useMemo, useCallback and React.memo.
    SeniorMedium◆ Commonly asked
    #react#perf
    PracticeGeeksforGeeks↗Search↗
  • Explain server components vs client components.
    SeniorHard◆ Commonly asked
    #react#ssr
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 1 question

Hiring Manager

Scope, ownership, and role-fit discussion with the manager.

  • How do you handle an underperforming teammate?
    Senior◆ Commonly asked
    #leadership
06

Round 06 · 2 questions

Behavioral / HR

Values, collaboration, and past-experience (STAR) questions.

  • Tell me about the most impactful project of your career.
    Senior◆ Commonly asked
    #impact#star
  • Describe a conflict with your manager and the outcome.
    Senior◆ Commonly asked
    #conflict#star

Practice each round across every company

  • DSA / Coding
  • Machine Coding
  • System Design
  • Tech Deep-Dive
  • Hiring Manager
  • Behavioral / HR

◆ This experience is composed from commonly reported questions for this role and level. Real, individually-shared interviews will be layered in over time.