Scale Engineer

Software Engineer I

Software EngineerL3Medium

The Software Engineer I (L3) interview at Circle is designed to assess foundational software engineering skills, problem-solving abilities, and cultural fit. It typically involves multiple rounds focusing on data structures, algorithms, system design basics, and behavioral aspects.

Rounds·4

Timeline·~7d

Experience·0 - 2 yrs

Comp band·US$90000 - US$120000

Interview time·165 min

Evaluation

What they measure.

  • Problem-solving skills
  • Algorithmic thinking
  • Data structure knowledge
  • Coding proficiency
  • Communication skills
  • Teamwork and collaboration
  • Cultural fit

Preparation

How to prepare.

Tips

  1. Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming, recursion).
  2. Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte, focusing on medium-difficulty problems.
  3. Understand basic system design concepts, such as scalability, availability, and common architectural patterns.
  4. Prepare for behavioral questions by thinking about your past experiences using the STAR method (Situation, Task, Action, Result).
  5. Research Circle's products, mission, and recent news to tailor your answers and show genuine interest.
  6. Practice explaining your thought process clearly and concisely, even when you're stuck.
  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 Fundamentals

Weeks 1-2: Data Structures (Arrays, Lists, Trees, Hash Tables). Practice basic operations.

Weeks 1-2: Focus on core data structures like arrays, linked lists, stacks, queues, trees (binary trees, BSTs, heaps), and hash tables. Practice problems related to traversal, insertion, deletion, and searching for each.

Questions

Commonly asked.

  • Given an array of integers, return indices of the two numbers such that they add up to a specific target.
  • Implement a function to reverse a linked list.
  • Design a basic URL shortener.
  • Tell me about a time you had to deal with a difficult stakeholder.
  • How would you approach optimizing a slow database query?
  • What are the differences between TCP and UDP?
  • Describe your experience with version control systems like Git.
  • Explain the concept of Big O notation and its importance.
  • How do you handle constructive criticism?
  • What interests you about working at Circle?

Locations

Regional differences.

Fig · Regions — 03 locations

01 / 03

Location

San Francisco Bay Area

Interview focus

Adaptability to new technologiesTeamwork and collaborationProblem-solving approach

Common questions

  • Tell me about a challenging project you worked on.
  • How do you handle disagreements within a team?
  • Describe a time you had to learn a new technology quickly.

Tips

  • Research common tech stacks used in the region.
  • Be prepared to discuss your contributions to open-source projects if applicable.
  • Highlight any experience with local tech communities or meetups.

Rounds

Round-by-round.

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

DSA

Coding questions at Circle.

Frequently reported on Circle loops

View all at Circle

Other guides

More at Circle.