Scale Engineer

Software Engineer

Software EngineerL2Medium

This interview process is for a Software Engineer (L2) position at Citadel. It is designed to assess a candidate's technical skills, problem-solving abilities, and cultural fit within the company.

Rounds·3

Timeline·~14d

Experience·2 - 5 yrs

Comp band·US$110000 - US$140000

Interview time·150 min

Evaluation

What they measure.

  • Technical proficiency in relevant programming languages and frameworks.
  • Ability to design and implement efficient algorithms.
  • Understanding of software development best practices.
  • Problem-solving and analytical skills.
  • Communication and collaboration abilities.
  • Cultural fit and alignment with Citadel's values.

Preparation

How to prepare.

Tips

  1. Review fundamental computer science concepts, including data structures, algorithms, and operating systems.
  2. Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium-difficulty problems.
  3. Study system design principles and common architectural patterns.
  4. Prepare to discuss your past projects and technical experiences in detail.
  5. Research Citadel's business, culture, and recent news.
  6. Prepare thoughtful questions to ask the interviewer.
  7. Practice behavioral questions using the STAR method (Situation, Task, Action, Result).

Study plan

Fig · Study plan — 04 phases

01 / 04
01

Phase 01 of 04

Data Structures and Algorithms

Weeks 1-2: Data Structures & Algorithms fundamentals. Practice implementations and complexity analysis.

Weeks 1-2: Focus on Data Structures (Arrays, Linked Lists, Stacks, Queues, Trees, Graphs, Hash Tables) and their common algorithms (Sorting, Searching, Graph Traversal). Practice implementing these from scratch and analyze their time and space complexity.

Questions

Commonly asked.

  • Write a function to find the kth smallest element in a sorted matrix.
  • Design a rate limiter for an API.
  • Tell me about a time you had to deal with a production issue.
  • What are the differences between TCP and UDP?
  • How would you optimize a slow database query?
  • Describe your experience with cloud platforms (AWS, Azure, GCP).
  • What is object-oriented programming and its principles?
  • Explain the concept of recursion with an example.
  • How do you ensure code quality in a team project?
  • What are your strengths and weaknesses as a software engineer?

Locations

Regional differences.

Fig · Regions — 02 locations

01 / 02

Location

New York

Interview focus

Problem-solving methodologiesCode quality and best practicesCollaboration and communication

Common questions

  • Discuss a challenging technical problem you solved in your previous role.
  • How do you approach debugging complex issues?
  • Describe a time you had to work with a difficult stakeholder.

Tips

  • Be prepared to discuss specific examples from your experience.
  • Emphasize your thought process when solving problems.
  • Showcase your ability to work effectively in a team.

Rounds

Round-by-round.

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

Med

Technical Interview - Data Structures And Algorithms · 45 min · Software Engineer / Senior Software Engineer

This round focuses on your core technical skills, primarily data structures and algorithms. You will be asked to solve one or two coding problems on a whiteboard or shared coding environment. The interviewer will assess your ability to understand the problem, devise an efficient solution, implement it correctly, and explain your reasoning. Be prepared to discuss time and space complexity.

What they look for

Strong understanding of data structures and algorithms.Ability to write clean, efficient, and well-structured code.Logical thinking and systematic problem-solving.Communication of thought process.

Evaluation

  • Correctness of the solution.
  • Efficiency of the algorithm (time and space complexity).
  • Code clarity and readability.
  • Ability to handle edge cases.
  • Problem-solving approach.

Sample questions

  • Given an array of integers, find the contiguous subarray with the largest sum.

    ArrayDynamic Programming

  • Implement a function to reverse a linked list.

    Linked List

  • Find the lowest common ancestor of two nodes in a binary tree.

    TreeRecursion

Prep for this round

  1. 01Practice coding problems on platforms like LeetCode, focusing on medium difficulty.
  2. 02Understand the time and space complexity of your solutions.
  3. 03Practice explaining your thought process out loud.
  4. 04Be comfortable with common data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming).

Common rejection reasons

  • ×Inability to articulate thought process clearly.
  • ×Lack of fundamental data structures and algorithms knowledge.
  • ×Poor coding style or inefficient solutions.
  • ×Failure to consider edge cases.

DSA

Coding questions at Citadel.

Frequently reported on Citadel loops

View all at Citadel

Other guides

More at Citadel.