What is the L4 position in Google?

At Google, an L4 position refers to a Software Engineer II role. This is a mid-level engineering position typically offered to candidates with 2 to 5 years of experience, depending on their technical skills and background. An L4 engineer is expected to have strong coding abilities, a good understanding of data structures and algorithms, and some exposure to system design and collaborative engineering work.

Here’s a breakdown of what the L4 role entails at Google:

1. Responsibilities at L4 (Software Engineer II)

a. Ownership of Projects

• Independent Problem Solving: L4 engineers are expected to take ownership of medium-sized features or components within a project. While they may work under the guidance of more senior engineers, they are expected to implement, test, and maintain parts of the system on their own.
• Contribution to Codebase: L4 engineers contribute meaningfully to the codebase, writing high-quality, maintainable code, and implementing solutions to problems that may span several components.

b. Collaboration with Other Engineers

• Code Reviews: At L4, engineers are often involved in code reviews, ensuring the quality of code written by peers and more junior engineers. They give and receive feedback to improve the overall development process.
• Teamwork: L4 engineers are typically part of a larger team and collaborate closely with Product Managers, Designers, and other Engineers to implement new features and resolve bugs.

c. System Design (Basic Level)

• While system design isn’t the primary focus for L4 engineers, they may be involved in designing smaller systems or components, especially as part of a team. For example:
  • Database schema design for small-scale projects.
  • API design and the integration of backend services.

L4 engineers may not be responsible for designing complex distributed systems yet, but they begin to develop their system design skills through mentoring and collaboration with more senior engineers.

2. Expectations and Skills for an L4 Engineer

a. Strong Coding and Problem-Solving Skills

• Coding Proficiency: L4 engineers are expected to be very strong in at least one programming language (e.g., Python, Java, C++, or Go).
• Algorithms and Data Structures: They should be proficient in solving algorithmic problems and have a strong grasp of data structures like arrays, trees, hashmaps, and graphs. Google’s technical interviews for L4 roles focus heavily on these topics.

b. Familiarity with Development Practices

• Version Control and Testing: L4 engineers should be comfortable using tools like Git for version control, writing unit tests, and practicing continuous integration (CI) and continuous deployment (CD).
• Debugging and Optimization: L4 engineers should be capable of debugging complex issues and optimizing their code for performance and scalability.

c. Collaboration and Mentorship

• Working with Teams: Collaboration is key at L4. Engineers at this level work closely with teammates, product managers, and UX designers to understand requirements and deliver solutions.
• Mentoring: L4 engineers may begin to mentor junior engineers (L3), helping them grow in their roles and offering feedback during code reviews.

3. Experience and Career Progression

a. Entry-Level to Mid-Level Engineer

• L4 is considered the entry point to a mid-level engineering role at Google. Many engineers progress to L4 after working for a couple of years as an L3 (entry-level software engineer), or they may join directly as an L4 if they have 2-5 years of relevant experience from other companies.

b. Path to L5 (Senior Software Engineer)

• To move from L4 to L5 (Senior Software Engineer), an engineer needs to demonstrate:
  • Technical leadership on projects.
  • The ability to design and implement larger systems or projects with minimal guidance.
  • Consistently strong performance in both coding and system design, along with more ownership and influence on team decisions.

L5 engineers are responsible for larger-scale projects and are expected to mentor other engineers and contribute to the overall technical strategy of their teams.

4. Compensation for L4 Engineers

a. Base Salary

• The base salary for an L4 engineer at Google typically ranges from 120,000 to 160,000 per year, depending on the location, market conditions, and candidate experience.

b. Stock and Bonus

• In addition to the base salary, Google provides equity (stock options) in the form of RSUs (Restricted Stock Units). L4 engineers typically receive stock grants, which can significantly increase total compensation.
• Performance bonuses of around 10-15% of the base salary are also common for L4 engineers.

c. Total Compensation

• The total compensation package (base salary + RSUs + bonus) for an L4 engineer can range from 150,000 to 250,000 or more, depending on factors like location and performance.

5. Key Differences Between L3 and L4

a. Scope of Work

• L3 Engineers (entry-level) typically work on smaller tasks and features under the guidance of more senior engineers.
• L4 Engineers are expected to handle more complex tasks independently and may be responsible for entire features or components of a project. They start to take on more ownership and leadership in delivering features.

b. System Design

• L4 engineers are expected to have a stronger understanding of basic system design compared to L3 engineers, though they still mostly work on smaller systems or components rather than entire large-scale distributed systems.

6. Transitioning to an L4 Role at Google

a. Internal Promotions

• If you’re an L3 at Google, you can transition to L4 through strong performance in your role, contributing to projects, mentoring, and showing growth in your technical and collaboration skills.

b. External Hires

• For external candidates, you can be hired directly into an L4 role if you have 2-5 years of experience in software engineering and demonstrate strong coding, problem-solving, and basic system design skills during interviews.

c. Interview Process for L4

• Google’s interview process for L4 positions includes:
  • Coding interviews: Focused on data structures, algorithms, and problem-solving.
  • System design interviews: At the L4 level, system design interviews may be simpler, focusing on designing basic components or services.
  • Behavioral interviews: Google also assesses collaboration, communication, and cultural fit through behavioral questions.

Conclusion

An L4 position at Google (Software Engineer II) is a mid-level engineering role for individuals with 2-5 years of experience. L4 engineers are expected to be strong coders, contribute independently to projects, and collaborate with teams on design and implementation. It’s a stepping stone toward more senior positions like L5 (Senior Software Engineer), where engineers take on larger, more complex projects and leadership responsibilities.

Key Takeaways:

• L4 engineers handle more complex projects and begin taking ownership of features.
• They contribute to code reviews, collaborate with other teams, and mentor junior engineers.
• Compensation for L4 engineers includes a competitive base salary, RSUs, and performance bonuses, with total compensation ranging from 150,000 to 250,000 or more.
• Career growth from L4 involves expanding technical skills, system design abilities, and leadership.