The L4 Software Engineer role at Google is a mid-level position for engineers with 3 to 6 years of experience. It's the entry point for engineers who are expected to contribute autonomously, drive technical discussions, and own features end-to-end.

This guide breaks down every step of the Google L4 interview process with tactical content — including interview structure, preparation plans, system design expectations, and high-signal questions reported by real candidates.

Table of Contents

1. Understanding Google’s L4 Role
2. Interview Process Overview
3. Phone Screen(s)
4. Onsite Interviews
   • Advanced Coding Rounds
   • System Design Interview
   • Behavioral & Leadership Interviews
5. Preparation Strategy
6. L4 vs. L5 Career Track
7. FAQs
8. Resources

Understanding Google’s L4 Role

L4 Responsibilities

Google’s L4 engineers are expected to:

• Own Features: Design, build, and maintain significant product features or services.
• Collaborate Cross-Functionally: Work with designers, PMs, and engineers across teams.
• Deliver Quality: Write scalable, maintainable, testable code.
• Mentor: Provide technical guidance to L3s or interns.
• Design Systems: Create design docs, propose architecture changes, and justify tradeoffs.

What L4 Means at Google

Interview Process Overview

The L4 interview process is rigorous and designed to assess your:

• Technical depth
• Design thinking
• Problem-solving
• Communication and leadership skills

PRO TIP: Browse phone screen and onsite interview experiences from Google on Onsites.fyi. Efficiently prepare by reading past interview experiences, understanding the interview process, and applying the right strategies.

Process Timeline

1. Recruiter Screen
2. Technical Phone Screen(s) (1–2)
3. Onsite Loop (4–5 Rounds)
   • 2 Coding Interviews
   • 1 System Design Interview
   • 1 Behavioral / Leadership Interview
   • (Optional) Role-Related Knowledge / Domain Round

Onsite can be virtual (Google Meet + Docs/CoderPad) or in-person.

Phone Screens

Structure

• 45 minutes
• 1 medium-to-hard algorithm question
• Conducted on Google Docs with video call
• Followed by clarification and edge case discussion

Sample Questions

• "Design a scheduler that executes tasks with cooldown periods."
• "Return the minimum spanning tree of a weighted undirected graph."
• "Given a string, return all possible palindromic partitions."

Evaluation Criteria

• Problem-solving clarity
• Data structure choice
• Clean, readable, modular code
• Thoughtful tradeoffs and testing

Onsite Interviews

Advanced Coding Rounds

Rounds: 2
Time: 45 minutes each
Focus: Optimized problem-solving, large input handling, space-time tradeoffs

Common Topics

• Segment Trees, Tries
• Advanced DP (State compression, memoization)
• Graph Algorithms (Dijkstra, Union-Find, Topological sort)
• K-way merge, Sliding window with monotonic queues
• Binary Search on Answer (e.g. capacity to ship packages)

Sample Questions

• “Find the median of two sorted arrays in O(log n)”
• “Implement autocomplete using a Trie and frequency ranking.”
• “Schedule maximum number of non-overlapping meetings.”
• “Detect cycle in a graph with colored nodes (DFS + backtracking).”

You’re expected to talk through your approach, handle input/output edge cases, and suggest optimizations.

System Design Interview

Round: 1
Time: 45 minutes
Goal: Assess your ability to design scalable, maintainable systems that solve real-world problems.

Expectation at L4

• Decompose complex systems into components
• Model APIs and data flows
• Make reasonable scalability assumptions
• Justify tradeoffs (SQL vs NoSQL, monolith vs microservices)

Common L4 System Design Prompts

• “Design Google Calendar’s event scheduling backend.”
• “Build a rate-limiting service for an API gateway.”
• “Design a URL shortener service with analytics and expiration.”
• “Design a file storage system (like Google Drive).”

Key Dimensions

🛠 Pro Tip: Use Google Docs as a whiteboard substitute. Structure your ideas clearly. Think aloud.

Behavioral & Leadership Interviews

Round: 1
Time: 45 minutes
Style: STAR framework preferred

Google expects L4s to demonstrate leadership without authority, autonomy, and collaboration.

Googleyness Traits

• Intellectual humility
• Comfort with ambiguity
• Growth mindset
• Bias for action
• Inclusion and respect

Common Behavioral Questions

• “Tell me about a time you took ownership of a failing project.”
• “Describe a disagreement with a coworker and how you resolved it.”
• “Have you ever led without formal authority?”
• “How do you ensure inclusivity in technical discussions?”

STAR Story Examples

Situation: Critical outage during product launch
Task: Identify root cause, coordinate response, restore service
Action: Created an incident playbook, delegated responsibilities
Result: Resolved issue within 45 mins and improved incident response SOP

🛑 Avoid: Rambling, vagueness, blaming others

✅ Include: Measurable impact, your unique contribution, what you learned

Preparation Strategy

✅ Phase 1: DSA Mastery (4–6 weeks)

• Topics: Trees, DP, Graphs, Bitmasks, Tries, Sliding Window
• Tools: LeetCode (Hard filter + Google tag), AlgoExpert, NeetCode
• Targets: Solve 150+ problems, review common patterns

✅ Phase 2: System Design Deep Dive (2–3 weeks)

• Books: Designing Data-Intensive Applications (Kleppmann), Grokking System Design
• Mock Designs: Do 5+ mock sessions (e.g., Rate limiter, Uber dispatch, Doc editor)
• Diagrams: Practice drawing clean component outlines on Google Docs

✅ Phase 3: Behavioral + Googliness

• Prepare 5–7 STAR stories from different angles:
  • Conflict resolution
  • Mentoring a peer
  • Taking initiative
  • Dealing with failure
  • Cross-team project leadership

L4 vs. L5 Career Track

Promotions to L5 require consistently demonstrating L5-level performance across multiple quarters.

FAQs

How hard is the L4 interview compared to L3?

Significantly harder — more autonomy expected, more real-world scenarios, deeper design and communication.

Can I apply directly to L4 without being an L3?

Yes, especially with 3+ years of experience. You'll be evaluated during interviews and may be down-leveled or up-leveled based on performance.

Will I be asked low-level system design?

At L4, yes. Expect object modeling, service decomposition, and limited distributed systems exposure.

What’s the compensation for Google L4 in 2025?

• Base: $160–180K
• Bonus: ~15%
• Equity (RSUs): $60K–$120K over 4 years
• TC (Bay Area): $240K–300K+

For more detailed insights and recent interview experiences, review Onsites.fyi. Browse hundreds of detailed Google interview experiences, helping you understand exactly what to expect and how to prepare effectively for the phone screen and onsite rounds at Google.

Want to dive deeper? Check out the complete guide to Google's Software Engineer High Level Interview Process for a comprehensive overview on all aspects of interviewing at Google.

Additional Resources

• Company Specific Interview Guides
  • The Comprehensive Guide to Big Tech Interviews: Proven Strategies for Every Stage of the Process
  • Meta Software Engineer Interview Questions: An In-Depth Guide to Success
  • Microsoft Software Engineering Interview Questions and Process: A Complete Guide
  • Meta Behavioral Interview Guide: A Comprehensive Guide
  • Mastering the Google Software Engineer Interview: A Detailed Step-by-Step Guide
  • Apple Phone Screen CoderPad Interview for Software Engineers in 2025
  • Cracking the Amazon Software Development Engineer (SDE) Interview Process: A Comprehensive 2025 Guide
  • Meta Software Engineer Phone Screen and Onsite Technical Interview Questions 2025

Note: This guide is based on publicly available information and insights from candidates who have undergone the Google interview process.