# Software Engineer II
**Role:** Software Engineer · **Level:** L3
**Company:** [Chime](https://scaleengineer.com/companies/chime)
**Difficulty:** Medium
**Salary:** US$100000 - US$130000
**Experience:** 2 - 5
**Timeline:** ~7 days
The Software Engineer II (L3) interview at Chime is designed to assess a candidate's technical proficiency, problem-solving abilities, and cultural fit within the company. This role typically requires 2-5 years of relevant experience. The interview process is structured to evaluate a candidate's ability to design, develop, and maintain scalable software solutions, collaborate effectively with team members, and contribute to Chime's mission of building innovative financial products.
Canonical: https://scaleengineer.com/interviews/chime/l3-software-engineer
---
## Overall evaluation

- Technical Skills
- Communication Skills
- Experience and Aptitude

## Questions asked

- Given an array of integers, find the contiguous subarray with the largest sum.
- Design a system to store and retrieve user profiles for a large-scale social media platform.
- Tell me about a time you disagreed with a team member. How did you resolve it?
- Implement a function to reverse a linked list.
- How would you design a rate limiter for an API?
- Describe a situation where you had to deal with ambiguity. How did you approach it?
- Write a function to find the kth smallest element in a binary search tree.
- Explain the difference between a process and a thread.
- How do you handle errors in a distributed system?
- What are your career goals for the next 3-5 years?

## Preparation tips

### lists

- Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming, recursion).
- Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte, focusing on medium-difficulty problems.
- Study system design concepts, including scalability, availability, reliability, and common design patterns.
- Prepare to discuss your past projects in detail, focusing on your contributions, challenges, and learnings.
- Understand Chime's products and mission to better align your answers with the company's goals.
- Practice behavioral questions using the STAR method (Situation, Task, Action, Result).
- Research common interview questions for Software Engineer roles at similar companies.

### studyPlan

- {"title":"Data Structures and Algorithms","longDescription":"Weeks 1-2: Focus on core data structures and algorithms. Cover arrays, linked lists, stacks, queues, trees (binary trees, BSTs, heaps), graphs, and hash tables. Practice common algorithms like sorting (quicksort, mergesort), searching (binary search), recursion, and basic dynamic programming. Aim to solve 2-3 medium problems daily.","shortDescription":"Weeks 1-2: Data Structures & Algorithms fundamentals. Practice 2-3 medium problems daily."}
- {"title":"System Design","longDescription":"Weeks 3-4: Dive into system design. Understand concepts like load balancing, caching, database sharding, message queues, and API design. Study common design patterns and architectural styles (e.g., microservices). Practice designing scalable systems like a URL shortener or a social media feed.","shortDescription":"Weeks 3-4: System Design concepts. Practice designing scalable systems."}
- {"title":"Behavioral and Cultural Fit","longDescription":"Week 5: Prepare for behavioral and situational questions. Reflect on past experiences and prepare stories using the STAR method for common questions related to teamwork, problem-solving, leadership, and handling conflict. Also, research Chime's values and mission.","shortDescription":"Week 5: Behavioral questions (STAR method) and Chime's values."}
- {"title":"Mock Interviews","longDescription":"Week 6: Mock interviews. Conduct mock interviews with peers or mentors to simulate the actual interview environment. Focus on receiving and incorporating feedback on both technical and communication aspects.","shortDescription":"Week 6: Mock interviews for practice and feedback."}

## Location differences

- {"location":"Remote","differences":{"tips":["Familiarize yourself with common cloud platforms (AWS, Azure, GCP) and their services.","Be prepared to discuss your experience with CI/CD pipelines and automated testing.","Highlight any experience with financial technologies or regulated industries.","Practice explaining technical concepts clearly and concisely, especially for remote interviews."],"interviewFocus":["Emphasis on practical application of data structures and algorithms in real-world scenarios.","Deeper dive into system design principles relevant to fintech applications.","Assessment of communication and collaboration skills in a remote or hybrid work environment."],"commonQuestions":["Describe a challenging technical problem you solved at your previous role.","How do you approach debugging a complex issue in a distributed system?","Tell me about a time you had to work with a difficult stakeholder.","What are your thoughts on microservices vs. monolith architecture?","How do you ensure the quality and reliability of your code?"]}}
- {"location":"On-site (e.g., San Francisco)","differences":{"tips":["Research Chime's specific office culture and values.","Be ready to discuss your contributions to team projects and how you foster collaboration.","Prepare examples that demonstrate your ability to learn quickly and adapt to new environments.","Understand the local tech landscape and how Chime fits into it."],"interviewFocus":["Focus on collaborative problem-solving and in-person team dynamics.","Assessment of adaptability to office environment and company culture.","Technical questions may be more tailored to specific team needs within the office location."],"commonQuestions":["Walk me through a project you are particularly proud of.","How do you handle conflicting priorities within a team?","Describe your experience with agile development methodologies.","What are the trade-offs between different database technologies (SQL vs. NoSQL)?","How do you stay updated with the latest technology trends?"]}}

## Round 1: Coding Challenge
**Type:** Technical Interview (Coding) · **Difficulty:** Medium · **Duration:** 45 min
Solve 1-2 coding problems focusing on data structures and algorithms.
This round focuses on assessing your core coding and problem-solving skills. You will be asked to solve one or two algorithmic problems, typically involving data structures and algorithms. The interviewer will expect you to write clean, efficient, and well-tested code, and to clearly explain your thought process throughout the problem-solving exercise. Be prepared to discuss time and space complexity.
**Interviewers look for:** A candidate who can translate a problem into a working code solution.; Someone who can explain their approach and justify their choices.; Attention to detail and ability to identify potential issues.
**Evaluation criteria:** Correctness of the solution.; Efficiency of the solution (time and space complexity).; Code clarity and readability.; Ability to handle edge cases.; Problem-solving approach.
**Common rejection reasons:** Inability to articulate thought process clearly.; Poor coding practices (e.g., unreadable code, lack of comments).; Failure to consider edge cases or constraints.; Lack of understanding of fundamental data structures and algorithms.
## Questions

- Given a binary tree, determine if it is a valid binary search tree.
- Find the length of the longest substring without repeating characters.

## Preparation tips

- Practice coding on a whiteboard or a shared editor.
- Think out loud and explain your approach before coding.
- Test your code with various inputs, including edge cases.
- Be ready to discuss alternative solutions and their trade-offs.

## Round 2: System Design
**Type:** System Design Interview · **Difficulty:** Medium-Hard · **Duration:** 60 min
Design a scalable software system, discussing architecture, components, and trade-offs.
This round assesses your ability to design and architect software systems. You'll be presented with a high-level problem (e.g., design Twitter's feed, design a URL shortener) and expected to propose a scalable and robust solution. This involves discussing components, data models, APIs, and trade-offs. Focus on clarifying requirements, breaking down the problem, and justifying your design decisions.
**Interviewers look for:** A candidate who can think about system architecture at a high level.; Someone who understands how different components interact.; An individual who can identify potential bottlenecks and propose solutions.; A candidate who can justify their design choices.
**Evaluation criteria:** Scalability of the proposed design.; Reliability and fault tolerance.; Clarity and completeness of the design.; Understanding of trade-offs.; Knowledge of relevant technologies (databases, caching, messaging).; Ability to handle ambiguity and make reasonable assumptions.
**Common rejection reasons:** Lack of understanding of distributed systems principles.; Inability to design scalable and reliable systems.; Poor trade-off analysis.; Not considering failure scenarios or bottlenecks.
## Questions

- Design a system like TinyURL.
- Design a news feed system for a social media platform.

## Preparation tips

- Review common system design concepts (load balancing, caching, databases, queues, APIs).
- Practice designing various systems.
- Be prepared to draw diagrams and explain them.
- Think about scalability, availability, and performance.

## Round 3: Behavioral and Fit
**Type:** Behavioral and Managerial Interview · **Difficulty:** Medium · **Duration:** 30 min
Discuss past experiences, behavioral competencies, and cultural fit using the STAR method.
This round focuses on your past experiences, behavioral competencies, and cultural fit. You'll be asked questions about how you've handled specific situations in previous roles, such as dealing with conflict, overcoming challenges, or working in a team. Use the STAR method (Situation, Task, Action, Result) to structure your answers. Be prepared to discuss your motivations for joining Chime and your career aspirations.
**Interviewers look for:** A candidate who can articulate their experiences effectively.; Someone who demonstrates positive collaboration and problem-solving skills.; An individual who aligns with Chime's culture and values.; Enthusiasm and a proactive attitude.
**Evaluation criteria:** Communication clarity.; Behavioral competencies (teamwork, problem-solving, adaptability).; Cultural fit with Chime's values.; Motivation and enthusiasm for the role and company.; Self-awareness and ability to reflect on past experiences.
**Common rejection reasons:** Poor communication skills.; Inability to provide specific examples.; Lack of self-awareness.; Not demonstrating alignment with company values.; Negative attitude or lack of enthusiasm.
## Questions

- Tell me about a time you failed. What did you learn from it?
- Describe a challenging project you worked on and how you contributed to its success.
- How do you handle constructive criticism?

## Preparation tips

- Prepare examples for common behavioral questions using the STAR method.
- Research Chime's mission, values, and culture.
- Think about why you are interested in this specific role and company.
- Be honest and authentic in your responses.