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Google·Software Engineer·Onsite - Multi Round·Intermediate

IntermediatePending
Jul 2026

Summary

Went through the full Google software engineer onsite loop, four rounds total, and now I'm sitting in the waiting room refreshing my inbox. Felt pretty solid through the first three rounds but the last one was a mess of brute force and dry runs with no actual code on the board.

Questions Asked (5)

Q1

Implement a solution using a trie data structure (medium difficulty).

Algorithms & Data Structures
Author's notes

Didn't get it to fully run, which still bothers me.

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AI HintsAI Generated

Suggested Approach

First, clarify the problem requirements and constraints, then design a trie with appropriate node structure and operations. Implement the solution step-by-step, explaining time and space complexity, and consider edge cases and potential optimizations.

Pro tip: Demonstrate deep understanding by discussing trade-offs between trie and other data structures (e.g., hash map) and mentioning real-world applications like autocomplete or spell check. Also, proactively handle edge cases such as empty strings or large inputs.

1. Clarify Requirements

Ask clarifying questions to understand the exact operations needed (insert, search, delete, prefix search) and constraints (character set, memory limits).

2. Design Trie Structure

Define the trie node with children (e.g., array or hash map) and a flag for end-of-word. Explain the choice based on character set and memory.

3. Implement Operations

Code the required operations (insert, search, startsWith, etc.) iteratively or recursively, ensuring correctness and efficiency.

4. Analyze Complexity

State time and space complexity for each operation, typically O(m) for time where m is key length, and O(n*m) for space where n is number of keys.

5. Test and Optimize

Walk through examples, test edge cases (empty string, long keys), and discuss possible optimizations like compressed tries or ternary search trees.

Key Points to Mention

  • Trie node structure: children mapping and end-of-word boolean
  • Time complexity: O(m) for insert/search/delete, where m is key length
  • Space complexity: O(n*m) worst case, but can be optimized with shared prefixes
  • Use cases: autocomplete, spell check, IP routing
  • Comparison with hash tables: tries offer ordered traversal and prefix search
  • Handling edge cases: empty strings, non-alphabetic characters, memory constraints

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

Q2

How would you handle various hypothetical workplace situations? (Behavioral / Googleyness round)

Adaptability & AmbiguityConflict Resolution
Author's notes

These rounds always feel like a vibe check more than anything.

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AI HintsAI Generated

Suggested Approach

Use the STAR method (Situation, Task, Action, Result) to structure your answers, focusing on your thought process and actions. Emphasize how you navigate ambiguity, collaborate with others, and drive towards a solution while demonstrating Google's values like user focus and teamwork.

Pro tip: Show self-awareness by acknowledging trade-offs and what you learned from the experience, and tailor your examples to Google's culture of innovation and user-centricity.

1. Understand the Scenario

Clarify the hypothetical situation by asking questions if needed, and identify the key challenges and stakeholders involved.

2. Outline Your Approach

Describe the steps you would take, emphasizing data-driven decision making, collaboration, and user impact.

3. Provide a Concrete Example

If possible, relate it to a past experience using the STAR method to demonstrate your skills in action.

4. Highlight Adaptability and Conflict Resolution

Explain how you would adjust to changing circumstances and resolve disagreements constructively.

5. Summarize and Reflect

Conclude with the outcome, what you learned, and how it aligns with Google's values and the role.

Key Points to Mention

  • Prioritizing user needs and Google's mission
  • Data-driven decision making and experimentation
  • Collaboration and communication with cross-functional teams
  • Adaptability to changing requirements and ambiguity
  • Constructive conflict resolution and consensus building
  • Ownership and accountability for outcomes

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

Q3

Solve an array and binary search problem (medium difficulty).

Algorithms & Data Structures
Author's notes

Finished in about 20 minutes, gave complexity, and had time to spare.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem and constraints, then discuss potential approaches including brute force and optimized binary search. Explain the binary search logic step-by-step, handle edge cases, and analyze time and space complexity.

Pro tip: At Google, interviewers value clear communication and the ability to derive the solution from first principles. Walk through your thought process, even if you get stuck, and always test your solution with examples.

1. Understand the Problem

Ask clarifying questions to confirm the input, output, constraints, and edge cases. Restate the problem in your own words to ensure alignment.

2. Explore Approaches

Discuss a brute-force solution first, then identify inefficiencies and propose a binary search approach. Explain why binary search is applicable (e.g., sorted array or monotonic property).

3. Design the Algorithm

Outline the binary search steps: initialize low and high pointers, compute mid, compare with target, and adjust pointers. Handle duplicates or boundary conditions as needed.

4. Analyze Complexity

State the time complexity (O(log n)) and space complexity (O(1) for iterative). Compare with brute force to highlight improvement.

5. Test and Validate

Walk through the algorithm with sample inputs, including edge cases like empty array, single element, target not present, and duplicates. Write pseudocode or actual code if required.

Key Points to Mention

  • Binary search requires a sorted array or a monotonic condition.
  • Use mid = low + (high - low) / 2 to avoid overflow.
  • Handle edge cases: empty array, target smaller than first element, target larger than last element.
  • Consider variations: finding first/last occurrence, rotated sorted array, or search in a 2D matrix.
  • Time complexity: O(log n) for binary search, O(1) space for iterative implementation.
  • Communicate clearly and test with examples to catch off-by-one errors.

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

Q4

Solve a graph or matrix traversal problem (medium difficulty, given as a follow-up after finishing the first problem early).

Algorithms & Data Structures
Author's notes

Came out of nowhere since I'd already solved the first one.

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AI HintsAI Generated

Suggested Approach

First, clarify the problem constraints and edge cases, then choose the appropriate traversal algorithm (BFS, DFS, or topological sort) based on the graph/matrix properties. Implement the solution with clean code, analyze time and space complexity, and test with examples to ensure correctness.

Pro tip: Since this is a follow-up, the interviewer expects you to handle it efficiently; demonstrate strong communication by thinking aloud and proactively discussing trade-offs between different traversal methods.

1. Clarify the problem

Ask questions to understand the input format, output requirements, constraints, and edge cases (e.g., disconnected graphs, cycles, empty inputs).

2. Choose the right traversal

Decide between BFS, DFS, or topological sort based on whether you need shortest paths, cycle detection, or ordering. Consider iterative vs recursive implementations.

3. Implement and optimize

Write clean, modular code. Use appropriate data structures (queues, stacks, visited sets) and optimize for time and space complexity.

4. Test and validate

Walk through test cases, including edge cases, and verify the solution. Discuss potential pitfalls and how to handle them.

5. Analyze complexity

Clearly state the time and space complexity, and explain how the chosen approach affects performance.

Key Points to Mention

  • Time and space complexity analysis (e.g., O(V+E) for graph traversal)
  • Handling of edge cases such as disconnected components, cycles, and empty inputs
  • Choice of data structures (queue for BFS, stack/recursion for DFS, visited set)
  • Trade-offs between iterative and recursive approaches (stack overflow, readability)
  • Potential optimizations like bidirectional search or early termination
  • Real-world applications or variations of the problem (e.g., shortest path, connected components)

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

Q5

Solve a hard graph problem involving a modified shortest-path algorithm (not the standard textbook version).

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

This one hurt.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the problem constraints and the exact modification to the shortest-path algorithm. Then, break down the problem into smaller subproblems, discuss potential approaches (e.g., Dijkstra with modifications, dynamic programming), and analyze their time/space complexity. Finally, code a clean solution and test with edge cases.

Pro tip: Demonstrate strong communication by thinking aloud and explaining your reasoning at each step. Google values how you approach problems, not just the final answer, so show your thought process and consider trade-offs between different solutions.

1. Clarify the problem

Ask questions to fully understand the problem: What is the exact modification? What are the constraints on graph size, edge weights, etc.? Are there any special cases?

2. Discuss potential approaches

Brainstorm possible algorithms (e.g., modified Dijkstra, Bellman-Ford, A*, dynamic programming) and discuss their applicability and trade-offs.

3. Choose and justify an approach

Select the most efficient approach based on constraints, and explain why it works and its time/space complexity.

4. Implement the solution

Write clean, modular code, explaining each part as you go. Handle edge cases and test with examples.

5. Analyze and optimize

Review the solution for correctness and efficiency. Discuss potential optimizations or alternative approaches if time permits.

Key Points to Mention

  • Time and space complexity analysis of the chosen algorithm
  • Correctness proof or invariant of the modified algorithm
  • Handling of edge cases (e.g., negative weights, disconnected graphs, cycles)
  • Trade-offs between different approaches (e.g., Dijkstra vs. Bellman-Ford)
  • Use of appropriate data structures (e.g., priority queue, adjacency list)
  • Testing strategy and validation with sample inputs

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