Google SDE2 Interview Guide
Published July 22, 2026 · Updated July 22, 2026
Evidence-backed preparation playbook for Google SDE2 interviews. 10 reported questions, top topics, difficulty breakdown, and a free assessment.
3-6 years
Most reported exp
Rounds reported
Technical 4qSystem Design 3qScreening 2qScenario 1q
Topics most frequently reported
✓System Design
2 questions · 20%
✓DSA / Trie
2 questions · 20%
✓DSA / Trees
1 question · 10%
·DSA / Graphs
1 question · 10%
·Domain
1 question · 10%
·React / Internals
1 question · 10%
Free · 10 minutes
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Top Questions — Ranked by Community Votes
These 6 questions appeared most in Google SDE2 reports. Master these first.
Google
Medium
Technical round
JavaC++Python
Given a binary tree, return the boundary of the tree in anti-clockwise direction starting from the root. The boundary consists of the left boundary, leaves, and the right boundary in reverse.
↑ 96 upvotes · 31 engineers asked this · SDE2
Google
Hard
System Design round
Distributed SystemsRedis
Design Google Search autocomplete. As a user types "wea", suggest "weather", "weather today", "weather London".
Cover: trie vs inverted index, personalisation, freshness, latency budget (<100ms), and how you handle offensive query suggestions.
↑ 79 upvotes · 55 engineers asked this · SDE2
Google
Hard
System Design round
Distributed SystemsKafkaGCP
Design Google Maps ETA calculation.
How do you compute the fastest route for 1B+ users in real time? Cover: graph representation of road network, Dijkstra vs A* vs Contraction Hierarchies, live traffic data ingestion, and how you handle road closures.
↑ 72 upvotes · 48 engineers asked this · SDE2
Google
Hard
Screening round
5-8 years
Explain how React's reconciliation algorithm decides what to re-render. A senior dev claims 'adding a key prop always makes things faster.' Is he right?
↑ 62 upvotes · 30 engineers asked this · SDE2
Google
Medium
Screening round
3-6 years
Explain gRPC vs REST API. When would you choose gRPC?
↑ 62 upvotes · 10 engineers asked this · SDE2
Google
Hard
Technical round
JavaPythonGo
Implement a topological sort for a directed acyclic graph. Then extend it to detect cycles and explain how this maps to dependency resolution in build systems like Bazel.
↑ 61 upvotes · 38 engineers asked this · SDE2
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Frequently asked questions
How hard is the Google SDE2 interview?
Mostly Hard difficulty based on 10 reported questions. Most questions cover System Design, DSA / Trie, DSA / Trees.
What topics does Google ask SDE2s?
Top reported topics: System Design (2 questions), DSA / Trie (2 questions), DSA / Trees (1 questions), DSA / Graphs (1 questions), Domain (1 questions).
How many rounds does Google have for SDE2?
Reported rounds: Technical, System Design, Screening, Scenario.
What experience level does Google hire SDE2s at?
Most reported: 3-6 years and 5-8 years.