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META · SENIOR SOFTWARE ENGINEER (SDE 3)

Meta senior engineer interview

The senior software engineer (SDE 3) level at Meta is E5 Senior Software Engineer, for senior engineers with about 5 to 10 years of experience. The rounds at this level, how each one is scored, and the questions to practise first.

From public candidate reports and Meta's careers pages, checked November 2026. Processes vary by team. AlgoRung is not affiliated with Meta.

Track my Meta prep
Meta titleE5 Senior Software Engineer
ExperienceSenior engineers with about 5 to 10 years of experience
Interviews after screeningAbout 5
System design roundYes

The Senior Software Engineer (SDE 3) rounds, in order

  1. Phone / recruiter screen · 45 min

    Two easy-to-medium coding problems in about 35 minutes of coding time, with code execution turned off.

    At Senior Software Engineer (SDE 3): Often a coding problem plus questions about your past systems; some companies (Uber) use it to set your level.

  2. Coding (DSA) · 45 min

    One traditional coding round without AI, usually two problems; interviewers expect you to find your own bugs.

    At Senior Software Engineer (SDE 3): Usually two rounds. Same difficulty, but interviewers expect quick, confident problem solving and production-quality code.

  3. AI-assisted coding · 60 min

    Since October 2025 this round gives you a multi-file project with an AI chat assistant, in three phases: fix a bug, build the core feature, then optimize for larger inputs.

    At Senior Software Engineer (SDE 3): Expected to plan the change, use the AI for routine parts, and catch its mistakes.

  4. System design (HLD) × 2 · 45 min

    System design or product design (product architecture), chosen to fit your background; E5+ usually get two design rounds and staff candidates must pass both.

    At Senior Software Engineer (SDE 3): One or two rounds that set your level. Expected to lead, size the system and go deep on two or three hard parts.

  5. Behavioral · 45 min

    Conflict, mistakes, missed deadlines, ambiguity and impact; senior candidates need multi-quarter projects with measurable impact.

    At Senior Software Engineer (SDE 3): Expected scope: projects across quarters, influencing other teams, mentoring.

  6. Team match · 30 min

    After the loop you meet several hiring managers, and the offer depends on a match where both sides opt in.

    At Senior Software Engineer (SDE 3): Down-leveling to SDE 2 is the most common surprise outcome.

  7. Hiring committee

    A review meeting recommends hire or no-hire from the packet; a senior committee mainly confirms level and compensation.

    At Senior Software Engineer (SDE 3): Down-leveling to SDE 2 is the most common surprise outcome.

What Meta interviewers look for

Behavioral rounds are based on the Company values (2022 set): Move Fast, Focus on Long-Term Impact, Build Awesome Things, Live in the Future, Be Direct and Respect Your Colleagues, Meta, Metamates, Me. Questions for each one.

Coding questions to practise for Meta Senior Software Engineer (SDE 3)

Usually two rounds. Same difficulty, but interviewers expect quick, confident problem solving and production-quality code.

Difficulty
Topic
14 questions
  1. Valid Word Abbreviation Easy Arrays & Hashing also LinkedIn
  2. Valid Palindrome II Easy Arrays & Hashing also Apple
  3. Subarray Sum Equals K Medium Arrays & Hashing also PhonePe
  4. Product of Array Except Self Medium Arrays & Hashing also Oracle
  5. Lowest Common Ancestor of a Binary Tree Medium Trees & BST also Google, Netflix, Atlassian +1
  6. Diameter of Binary Tree Easy Trees & BST also Adobe
  7. Copy List with Random Pointer Medium Linked List also Amazon, Microsoft
  8. Minimum Window Substring Hard Arrays & Hashing also Google, LinkedIn, Oracle
  9. Group Anagrams Medium Arrays & Hashing also Amazon, Oracle
  10. Number of Islands Medium Graphs also Amazon, Microsoft, Goldman Sachs +1
  11. Meeting Rooms II Medium Intervals also Amazon
  12. Alien Dictionary Hard Graphs also Amazon, Airbnb
  13. Serialize and Deserialize Binary Tree Hard Trees & BST also Amazon, LinkedIn, Oracle
  14. Basic Calculator Hard Stack

How the coding round is scored · The online assessment

System design at Senior Software Engineer (SDE 3)

E3/E4 design is basic or absent. From E5 there are usually two design rounds and they weigh heavily on level: system design (infrastructure, scale, storage) or product design (APIs, data flow, data models). Prompts are mostly Meta products: Feed, Messenger, Instagram, live comments, typeahead.

All Meta system design questions

Questions people ask

How many rounds are in the Meta Senior Software Engineer (SDE 3) interview?

About 5 interviews after the screening: phone / recruiter screen, coding (dsa), ai-assisted coding, system design (hld), behavioral, team match, hiring committee.

Is there a system design round for Meta Senior Software Engineer (SDE 3)?

Yes. E3/E4 design is basic or absent. From E5 there are usually two design rounds and they weigh heavily on level: system design (infrastructure, scale, storage) or product design (APIs, data flow, data models). Prompts are mostly Meta products: Feed, Messenger, Instagram, live comments, typeahead.

What coding questions does Meta ask at Senior Software Engineer (SDE 3)?

The same question pool is used across levels; the bar rises with level. Most reported: Valid Word Abbreviation, Valid Palindrome II, Subarray Sum Equals K, Product of Array Except Self, Lowest Common Ancestor of a Binary Tree.

What does Meta expect in coding rounds at Senior Software Engineer (SDE 3)?

Usually two rounds. Same difficulty, but interviewers expect quick, confident problem solving and production-quality code.

Senior Software Engineer (SDE 3) interviews at other companies

Senior Software Engineer (SDE 3) interview questions across all companies · Behavioral questions