Scale Engineer

Software Engineer 2

Software EngineerL5Medium to Hard

The Software Engineer 2 (L5) interview at Affirm is designed to assess a candidate's technical proficiency, problem-solving abilities, system design skills, and cultural fit. This role typically requires 3-5 years of relevant experience. The process involves multiple rounds, including technical interviews, a system design interview, and a behavioral/managerial interview.

Rounds·3

Timeline·~7d

Experience·3 - 5 yrs

Comp band·US$130000 - US$160000

Interview time·150 min

Evaluation

What they measure.

  • Problem-solving skills: Ability to break down complex problems, identify edge cases, and devise efficient solutions.
  • Coding proficiency: Clean, well-structured, and efficient code.
  • Data structures and algorithms: Understanding and application of fundamental CS concepts.
  • System design: Ability to design scalable, reliable, and maintainable systems.
  • Communication: Clarity in explaining technical concepts and thought processes.
  • Collaboration: Ability to work effectively with others and contribute to team goals.
  • Cultural fit: Alignment with Affirm's values and work environment.

Preparation

How to prepare.

Tips

  1. Review fundamental data structures and algorithms (arrays, linked lists, trees, graphs, hash maps, sorting, searching).
  2. Practice coding problems on platforms like LeetCode, HackerRank, or similar.
  3. Study system design principles (scalability, availability, consistency, databases, caching, load balancing, message queues).
  4. Prepare to discuss your past projects in detail, focusing on your contributions and technical challenges.
  5. Understand Affirm's business model, products, and values.
  6. Practice behavioral questions using the STAR method (Situation, Task, Action, Result).
  7. Prepare questions to ask the interviewer about the role, team, and company culture.

Study plan

Fig · Study plan — 05 phases

01 / 05
01

Phase 01 of 05

Data Structures and Algorithms Fundamentals

Weeks 1-2: Data Structures & Algorithms (Easy/Medium)

Week 1-2: Focus on core data structures (arrays, linked lists, stacks, queues, trees, graphs, hash tables) and algorithms (sorting, searching, recursion, dynamic programming). Practice implementing these and solving related problems on platforms like LeetCode (Easy/Medium).

Questions

Commonly asked.

  • Given an array of integers, find the contiguous subarray with the largest sum.
  • Design a system to shorten URLs.
  • Describe a time you had to deal with a difficult stakeholder.
  • How would you implement a cache for a web application?
  • What are the differences between TCP and UDP?
  • Tell me about a project you are particularly proud of.
  • How do you handle production incidents?
  • Design a notification system.
  • Explain the concept of eventual consistency.
  • What are your career goals?

Locations

Regional differences.

Fig · Regions — 02 locations

01 / 02

Location

San Francisco, USA

Interview focus

Emphasis on practical application of data structures and algorithms.Deeper dive into distributed systems concepts relevant to Affirm's platform.Understanding of cloud-native technologies (AWS, Kubernetes).Cultural alignment with Affirm's values (e.g., customer obsession, bias for action).

Common questions

  • Discuss a challenging technical problem you solved at your previous company.
  • How do you approach debugging a complex issue in a distributed system?
  • Describe a time you had to mentor a junior engineer.
  • What are your thoughts on microservices vs. monolith architectures in the context of e-commerce?
  • How do you ensure the scalability and reliability of your code?

Tips

  • Be prepared to discuss specific examples from your experience that demonstrate problem-solving and collaboration.
  • Familiarize yourself with Affirm's business and how technology supports it.
  • Practice explaining complex technical concepts clearly and concisely.
  • Research common interview questions for L5 Software Engineers at similar tech companies.

Rounds

Round-by-round.

Expand a step for evaluation criteria, sample questions, and prep notes.

Med

Technical Interview (Coding) · 45 min · Software Engineer

This round focuses on your fundamental programming skills. You will be asked to solve one or two coding problems, typically involving data structures and algorithms. The interviewer will assess your ability to understand the problem, devise a solution, write clean code, and explain your thought process. Expect to discuss time and space complexity and potential optimizations.

What they look for

Strong problem-solving skills.Proficiency in at least one programming language.Ability to write clean and efficient code.Understanding of time and space complexity.

Evaluation

  • Correctness of the solution.
  • Efficiency of the algorithm (time and space complexity).
  • Code clarity and style.
  • Ability to explain the thought process.
  • Handling of edge cases.

Sample questions

  • Given a binary tree, invert the tree.

    TreeRecursionBinary Tree

  • Find the kth largest element in an unsorted array.

    ArraySortingHeap

Prep for this round

  1. 01Practice coding problems on platforms like LeetCode, focusing on medium-difficulty questions.
  2. 02Be comfortable explaining your approach before you start coding.
  3. 03Write code that is readable and well-commented.
  4. 04Test your code with various inputs, including edge cases.

Common rejection reasons

  • ×Inability to solve coding problems efficiently.
  • ×Poor code quality (not clean, readable, or maintainable).
  • ×Lack of understanding of fundamental data structures and algorithms.
  • ×Failure to consider edge cases or optimize solutions.

DSA

Coding questions at Affirm.

Frequently reported on Affirm loops

View all at Affirm

Other guides

More at Affirm.