← Google Interview Insights

Google·Software Engineer·Onsite - Multi Round·Junior

JuniorPending
Sep 2026

Summary

Two rounds of coding interviews at Google for a SWE intern role. Both interviewers were relaxed and the problems felt manageable, though the second one had a weird moment where we were basically solving two different questions until I caught on.

Questions Asked (2)

Q1

Given a coding problem related to video platform infrastructure, solve it and then optimize for better time complexity as the constraints are modified.

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

The interview ran way over time, like 25 minutes over, because the interviewer kept adding new scenarios.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

Start by clarifying the problem, constraints, and expected input/output. Then, propose a straightforward solution, analyze its time and space complexity, and systematically optimize it by identifying bottlenecks and applying appropriate data structures or algorithms. Finally, discuss trade-offs and test with edge cases.

Pro tip: Always verbalize your thought process and consider multiple optimization paths; Google values how you approach problems more than just the final answer. Also, proactively discuss how you would handle scale, as video platform infrastructure often involves large datasets.

1. Clarify the Problem

Ask questions to fully understand the problem, including input format, output requirements, constraints, and edge cases. Confirm assumptions with the interviewer.

2. Propose a Baseline Solution

Outline a simple, correct solution (e.g., brute force) and analyze its time and space complexity. This establishes a foundation for optimization.

3. Identify Bottlenecks and Optimize

Determine the limiting factors (e.g., time, space) and propose improvements using better data structures, algorithms, or mathematical insights. Explain how the new approach reduces complexity.

4. Discuss Trade-offs and Constraints

Compare the optimized solution with alternatives, highlighting trade-offs in time, space, readability, and scalability. Address how changes in constraints affect the choice.

5. Test and Validate

Walk through the solution with sample inputs, including edge cases, to verify correctness and performance. Mention potential pitfalls and how to handle them.

Key Points to Mention

  • Time and space complexity analysis (Big O notation) for each proposed solution.
  • Use of appropriate data structures (e.g., hash maps, heaps, trees) to optimize operations.
  • Trade-offs between different approaches (e.g., precomputation vs. on-the-fly, memory vs. speed).
  • Scalability considerations for video platform infrastructure (e.g., handling large streams, distributed systems).
  • Edge cases and how to handle them (e.g., empty input, large values, concurrency).
  • Clear communication of thought process and willingness to adapt based on interviewer feedback.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q2

Solve a coding problem efficiently, then determine whether the time complexity can be further improved.

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

Embarrassingly, we spent a chunk of time solving slightly different problems because I misread what he was asking.

Create a free account to read the full note

AI HintsAI Generated

Suggested Approach

Start by clarifying the problem requirements and constraints, then propose a straightforward solution with its time and space complexity. After implementing, systematically analyze whether the complexity can be improved by considering alternative data structures or algorithmic paradigms, and discuss trade-offs.

Pro tip: Always state the complexity of your initial solution before optimizing, and when suggesting improvements, quantify the potential gain and any added implementation complexity. This shows you can balance performance with maintainability.

1. Understand and Clarify

Restate the problem in your own words, ask clarifying questions about input size, edge cases, and expected output. Confirm the constraints to guide your solution's efficiency.

2. Propose a Baseline Solution

Describe a simple, correct approach (e.g., brute force) and analyze its time and space complexity. This establishes a starting point for optimization.

3. Implement and Test

Write clean, modular code for the baseline solution, then test with examples and edge cases to ensure correctness before optimizing.

4. Analyze and Optimize

Identify bottlenecks in the baseline solution and propose improvements using better data structures, algorithms, or mathematical insights. Compare the new complexity with the old one.

5. Discuss Trade-offs and Finalize

Explain the trade-offs between the optimized and baseline solutions (e.g., time vs. space, readability vs. performance) and justify your final choice based on the context.

Key Points to Mention

  • Time and space complexity analysis (Big O notation) for each proposed solution
  • Common optimization techniques: using hash maps, two pointers, dynamic programming, greedy algorithms, etc.
  • Trade-offs between different approaches (e.g., time vs. space, simplicity vs. performance)
  • Edge cases and constraints that might affect the choice of algorithm
  • The importance of code readability and maintainability in production environments
  • How to validate the optimized solution with test cases and performance benchmarks

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.