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Google·Software Engineer·Onsite - Multi Round·Junior

JuniorRejected
Jun 2026

Summary

Three rounds of technical interviews at Google for a new grad software engineering role, covering graphs, trees, and matrix problems. The coding went fine but the behavioral portions tripped me up more than expected, and the recruiter feedback confirmed what I already suspected.

Questions Asked (4)

Q1

Solve a hard graph problem, starting with a brute-force approach and then optimizing it.

Algorithms & Data Structures
Author's notes

Managed to get through both the naive and optimized versions, and the follow-ups weren't too bad.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem and constraints, then propose a brute-force solution with its time/space complexity. Next, identify bottlenecks and optimize using appropriate data structures or algorithms, explaining trade-offs and edge cases.

Pro tip: Always discuss the brute-force first to show you can reason from first principles, then optimize incrementally while communicating your thought process. This demonstrates structured problem-solving and collaboration, which Google values.

1. Clarify the problem

Ask clarifying questions to understand input size, edge cases, and constraints. Confirm the expected output and any assumptions.

2. Brute-force solution

Propose a straightforward approach, even if inefficient. Analyze its time and space complexity to establish a baseline.

3. Identify bottlenecks

Pinpoint inefficiencies in the brute-force method, such as repeated computations or unnecessary traversals.

4. Optimize

Apply algorithmic techniques (e.g., BFS/DFS, Dijkstra, Union-Find, DP) or data structures (heaps, hash maps) to improve complexity. Explain why the optimization works.

5. Test and discuss trade-offs

Walk through edge cases, verify correctness, and compare the optimized solution with the brute-force in terms of time, space, and readability.

Key Points to Mention

  • Time and space complexity analysis for both brute-force and optimized solutions
  • Graph traversal algorithms (BFS, DFS) and their appropriate use cases
  • Shortest path algorithms (Dijkstra, Bellman-Ford) and their constraints
  • Union-Find (Disjoint Set Union) for connectivity problems
  • Dynamic programming on graphs (e.g., for DAGs or state-based problems)
  • Edge cases: disconnected graphs, cycles, negative weights, large input sizes

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

Q2

Work through a challenging tree or graph problem, again presenting a brute-force solution before arriving at an optimized one.

Algorithms & Data Structures
Author's notes

Similar structure to the first round so I felt more settled going in.

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AI HintsAI Generated

Suggested Approach

Start by restating the problem and clarifying constraints, then propose a brute-force solution with its time/space complexity. Identify inefficiencies and iteratively optimize using appropriate data structures or algorithmic paradigms (e.g., BFS/DFS, dynamic programming, union-find), explaining trade-offs at each step.

Pro tip: Verbalize your thought process and explicitly state why the brute-force is insufficient, then connect the optimization to a known pattern (e.g., 'this is a shortest path problem, so BFS is optimal'). This shows structured problem-solving and deep understanding.

1. Clarify the problem

Ask questions to confirm input/output, edge cases, and constraints (e.g., graph size, tree properties). Restate the problem in your own words to ensure alignment.

2. Brute-force solution

Describe a straightforward approach (e.g., exhaustive search, recursion without memoization) and analyze its time and space complexity. Acknowledge its limitations.

3. Identify bottlenecks

Point out inefficiencies in the brute-force (e.g., repeated computations, unnecessary traversals) and suggest potential optimizations.

4. Optimized solution

Propose an improved algorithm using appropriate techniques (e.g., BFS/DFS with visited set, dynamic programming, union-find) and explain why it's better. Analyze the new complexity.

5. Test and discuss trade-offs

Walk through a small example to verify correctness, consider edge cases, and discuss trade-offs between different optimized approaches (e.g., time vs. space).

Key Points to Mention

  • Time and space complexity analysis for both brute-force and optimized solutions
  • Choice of data structures (e.g., adjacency list vs. matrix, queue for BFS, stack for DFS)
  • Handling of edge cases (e.g., empty graph, disconnected components, cycles)
  • Correctness argument for the optimized solution (e.g., why BFS guarantees shortest path in unweighted graphs)
  • Potential follow-up optimizations or alternative approaches (e.g., bidirectional search, A*)
  • Real-world applications or similar problems to demonstrate broader understanding

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

Q3

Solve a matrix operation problem with multiple follow-up questions, aiming for an optimal solution.

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

Actually felt good about this one.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem constraints and expected input/output, then propose a brute-force solution and iteratively optimize it using appropriate data structures or algorithms. Discuss trade-offs between time and space complexity, and be prepared to handle follow-up questions by extending your solution or considering edge cases.

Pro tip: Demonstrate structured thinking by explicitly stating your assumptions and walking through a small example before coding. This shows clarity and helps catch misunderstandings early.

1. Clarify the Problem

Ask questions to understand the matrix dimensions, operation type, constraints, and expected output format. Confirm edge cases like empty matrices or non-square matrices.

2. Propose a Brute-Force Solution

Outline a straightforward approach, even if inefficient, to establish a baseline. Discuss its time and space complexity.

3. Optimize the Solution

Identify bottlenecks and suggest improvements using better algorithms or data structures. Explain how the optimization reduces complexity.

4. Analyze Trade-offs

Compare the brute-force and optimized solutions in terms of time, space, and code complexity. Discuss scenarios where each might be preferable.

5. Handle Follow-ups and Edge Cases

Anticipate follow-up questions by considering variations like different matrix operations, larger inputs, or memory constraints. Test your solution with edge cases.

Key Points to Mention

  • Time and space complexity analysis for each approach
  • Use of appropriate data structures (e.g., arrays, hash maps) for optimization
  • Trade-offs between different algorithms (e.g., dynamic programming vs. greedy)
  • Handling of edge cases such as empty matrices, non-square matrices, or integer overflow
  • Scalability considerations for large matrices
  • Clear communication of thought process and assumptions

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

Q4

Describe how you collaborate with others and demonstrate the mindset and values you'd bring to a team environment.

Adaptability & AmbiguityCross-functional Alignment
Author's notes

This is what sank me.

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AI HintsAI Generated

Suggested Approach

Use the STAR method to describe a specific cross-functional collaboration, emphasizing how you navigated ambiguity and aligned diverse stakeholders. Highlight the mindset and values you brought, such as humility, user-focus, and proactive communication, and connect them to Google's collaborative culture.

Pro tip: Show how you turned a disagreement into a better outcome by actively seeking input and iterating—Google values intellectual humility and data-driven decisions over being right.

1. Set the Context

Briefly describe the project, your role, and the cross-functional team involved, including any ambiguity or conflicting priorities.

2. Describe Your Actions

Explain how you proactively communicated, sought diverse perspectives, and adapted your approach to align the team and drive progress.

3. Highlight the Mindset

Articulate the values and mindset you demonstrated, such as user-first thinking, humility, and a bias for action, and why they mattered.

4. Share the Outcome

Quantify the results (e.g., improved efficiency, successful launch) and reflect on what you learned about effective collaboration.

5. Connect to Google

Tie your experience to Google's collaborative culture and the role, showing how you'd contribute to and learn from the team.

Key Points to Mention

  • Cross-functional collaboration with PM, UX, and other engineers
  • Navigating ambiguity by breaking down problems and aligning on goals
  • Active listening and incorporating diverse perspectives
  • Proactive communication and transparency
  • User-first mindset and data-driven decision making
  • Humility and willingness to learn from others

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