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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

← Mercado Libre

Senior Frontend at Mercado Libre

FrontendSeniorOffer◆ Commonly asked· 2023

6-round senior frontend process. 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.

  • Product of array except self.
    SeniorMedium◆ Commonly asked
    #array#prefix-sum
    PracticeLeetCode↗GeeksforGeeks↗
  • Invert a binary tree.
    SeniorEasy◆ Commonly asked
    #tree
    PracticeLeetCode↗GeeksforGeeks↗
  • Sliding window maximum.
    SeniorHard◆ Commonly asked
    #deque#sliding-window
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 2 questions

Machine Coding

Build a working component or service under time pressure.

  • Build a nested, collapsible comment thread.
    SeniorMedium◆ Commonly asked
    #react#recursion
    PracticeGeeksforGeeks↗Search↗
  • Build a color-picker with hex/rgb sync.
    SeniorMedium◆ Commonly asked
    #react#ui
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 2 questions

System Design

High-level architecture of a large-scale system.

  • Design an online code judge / evaluator.
    SeniorHard◆ Commonly asked
    #sandboxing#queues
    PracticeGeeksforGeeks↗Search↗
  • Design a content delivery network (CDN).
    SeniorHard◆ Commonly asked
    #cdn#cache#edge
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • What is the difference between var, let and const?
    SeniorEasy◆ Commonly asked
    #javascript
    PracticeGeeksforGeeks↗Search↗
  • localStorage vs sessionStorage vs cookies — when to use each?
    SeniorEasy◆ Commonly asked
    #browser
    PracticeGeeksforGeeks↗Search↗
  • Explain how Promises work and implement Promise.all.
    SeniorMedium◆ Commonly asked
    #javascript#async
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 1 question

Hiring Manager

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

  • What is the biggest system you have designed, and why those choices?
    Senior◆ Commonly asked
    #architecture
06

Round 06 · 2 questions

Behavioral / HR

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

  • Describe a time you had to deliver bad news.
    Senior◆ Commonly asked
    #communication#star
  • Tell me about receiving hard feedback and acting on it.
    Senior◆ Commonly asked
    #feedback#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.