# Junior Software Engineer
**Role:** Software Engineer · **Level:** L1
**Company:** [Hudson River Trading](https://scaleengineer.com/companies/hudson-river-trading)
**Difficulty:** Medium
**Salary:** US$75000 - US$95000
**Experience:** 0 - 2
**Timeline:** ~14 days
The Junior Software Engineer (L1) interview at Hudson River Trading is designed to assess foundational programming skills, problem-solving abilities, and a candidate's potential for growth within the company. It focuses on core computer science concepts and practical application.
Canonical: https://scaleengineer.com/interviews/hudson-river-trading/l1-software-engineer
---
## Overall evaluation

- Technical Skills
- Soft Skills and Potential

## Questions asked

- Write a function to reverse a linked list.
- Given an array of integers, find the two numbers that add up to a specific target.
- Explain the difference between a stack and a queue.
- What is recursion? Provide an example.
- How would you find the most frequent element in an array?
- Describe a time you faced a technical challenge and how you overcame it.
- Why are you interested in working at Hudson River Trading?
- Tell me about a project you worked on that you are proud of.
- How do you approach learning a new technology?
- What are your strengths and weaknesses as a software engineer?

## Preparation tips

### lists

- Review fundamental data structures (arrays, linked lists, trees, hash maps) and algorithms (sorting, searching, graph traversal).
- Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte, focusing on easy and medium difficulty.
- Understand Big O notation for time and space complexity.
- Brush up on core programming concepts in your preferred language (e.g., object-oriented programming, memory management).
- Prepare to discuss your past projects in detail, highlighting your contributions and technical challenges.
- Research Hudson River Trading's business and culture to understand our values and mission.
- Practice explaining your thought process out loud as you solve problems.
- Be ready for behavioral questions about teamwork, problem-solving, and learning experiences.

### studyPlan

- {"title":"Data Structures Fundamentals","longDescription":"Weeks 1-2: Focus on foundational data structures like arrays, linked lists, stacks, queues, and hash maps. Practice implementing them and solving problems related to their usage. Understand their time and space complexity. Begin with easy LeetCode problems.","shortDescription":"Weeks 1-2: Data Structures (Arrays, Linked Lists, Stacks, Queues, Hash Maps) & Easy Problems."}
- {"title":"Algorithm Basics","longDescription":"Weeks 3-4: Dive into algorithms, including sorting (bubble, merge, quick), searching (binary search), and basic graph traversal (BFS, DFS). Practice problems that require applying these algorithms. Continue with easy to medium LeetCode problems.","shortDescription":"Weeks 3-4: Algorithms (Sorting, Searching, BFS, DFS) & Easy/Medium Problems."}
- {"title":"Trees and Complexity Analysis","longDescription":"Week 5: Focus on trees (binary trees, BSTs) and more advanced hash map applications. Practice problems involving tree traversals and efficient lookups. Introduce Big O notation for analyzing algorithm efficiency.","shortDescription":"Week 5: Trees, Advanced Hash Maps & Big O Notation."}
- {"title":"Language Proficiency and Behavioral Preparation","longDescription":"Week 6: Review core programming language concepts (e.g., OOP principles, memory management if applicable). Practice coding problems that test these concepts. Prepare behavioral answers by reflecting on past experiences.","shortDescription":"Week 6: Language Fundamentals & Behavioral Prep."}

## Location differences

- {"location":"New York","differences":{"tips":["For New York: Be prepared for a fast-paced environment. Emphasize your ability to learn quickly and contribute to a collaborative team.","For Chicago: Highlight any experience with distributed systems or high-frequency trading concepts, even at a foundational level.","For London: Showcase your understanding of European market structures or any relevant financial technology exposure.","For all locations: Practice explaining your thought process clearly and concisely. Be ready to discuss your resume in detail."],"interviewFocus":["Understanding of fundamental data structures and algorithms.","Ability to write clean, efficient, and well-documented code.","Problem-solving approach and logical thinking.","Communication skills and ability to articulate technical concepts.","Enthusiasm for learning and adapting to new technologies."],"commonQuestions":["Explain the difference between a process and a thread.","Describe a situation where you had to debug a complex issue. How did you approach it?","What are some common data structures you've used, and when would you choose one over another?","How do you ensure the quality of your code?","Tell me about a project you're particularly proud of and your role in it."]}}
- {"location":"Chicago","differences":{"tips":["For New York: Be prepared for a fast-paced environment. Emphasize your ability to learn quickly and contribute to a collaborative team.","For Chicago: Highlight any experience with distributed systems or high-frequency trading concepts, even at a foundational level.","For London: Showcase your understanding of European market structures or any relevant financial technology exposure.","For all locations: Practice explaining your thought process clearly and concisely. Be ready to discuss your resume in detail."],"interviewFocus":["Understanding of fundamental data structures and algorithms.","Ability to write clean, efficient, and well-documented code.","Problem-solving approach and logical thinking.","Communication skills and ability to articulate technical concepts.","Enthusiasm for learning and adapting to new technologies."],"commonQuestions":["Explain the difference between a process and a thread.","Describe a situation where you had to debug a complex issue. How did you approach it?","What are some common data structures you've used, and when would you choose one over another?","How do you ensure the quality of your code?","Tell me about a project you're particularly proud of and your role in it."]}}
- {"location":"London","differences":{"tips":["For New York: Be prepared for a fast-paced environment. Emphasize your ability to learn quickly and contribute to a collaborative team.","For Chicago: Highlight any experience with distributed systems or high-frequency trading concepts, even at a foundational level.","For London: Showcase your understanding of European market structures or any relevant financial technology exposure.","For all locations: Practice explaining your thought process clearly and concisely. Be ready to discuss your resume in detail."],"interviewFocus":["Understanding of fundamental data structures and algorithms.","Ability to write clean, efficient, and well-documented code.","Problem-solving approach and logical thinking.","Communication skills and ability to articulate technical concepts.","Enthusiasm for learning and adapting to new technologies."],"commonQuestions":["Explain the difference between a process and a thread.","Describe a situation where you had to debug a complex issue. How did you approach it?","What are some common data structures you've used, and when would you choose one over another?","How do you ensure the quality of your code?","Tell me about a project you're particularly proud of and your role in it."]}}

## Round 1: Data Structures and Algorithms (DSA) Round
**Type:** Technical Interview · **Difficulty:** Medium · **Duration:** 45 min
Coding challenge focused on data structures and algorithms.
This round is a technical screening focused on assessing your core programming and problem-solving skills. You will be asked to solve one or two coding problems, typically involving data structures and algorithms. The interviewer will evaluate your approach, the correctness and efficiency of your code, and your ability to explain your reasoning. Expect to write code in a shared editor or on a whiteboard.
**Interviewers look for:** A systematic approach to problem-solving.; Understanding of basic data structures and algorithms.; Ability to write functional and reasonably efficient code.; Clear communication of thought process.; Potential to learn and grow.
**Evaluation criteria:** Problem-solving approach; Correctness of the solution; Efficiency of the solution (time and space complexity); Code clarity and style; Ability to explain the solution
**Common rejection reasons:** Inability to articulate thought process.; Fundamental misunderstanding of data structures or algorithms.; Code that is incorrect or highly inefficient.; Poor communication skills.; Lack of enthusiasm or curiosity.
## Questions

- Given an array of integers, return indices of the two numbers such that they add up to a specific target.
- Implement a function to check if a binary tree is a Binary Search Tree (BST).
- Find the kth smallest element in an unsorted array.

## Preparation tips

- Practice coding problems on platforms like LeetCode (Easy/Medium).
- Focus on explaining your thought process clearly.
- Be prepared to discuss time and space complexity.
- Review common data structures and algorithms.

## Round 2: Technical Deep Dive and Behavioral Round
**Type:** Technical and Behavioral Interview · **Difficulty:** Medium · **Duration:** 45 min
Discussion on resume, past projects, and behavioral aspects.
This round typically involves a discussion about your resume, past projects, and technical experiences. The interviewer will delve into the details of your projects, asking about your specific contributions, technical challenges faced, and solutions implemented. Behavioral questions related to teamwork, problem-solving, and learning will also be common. The goal is to understand your practical experience and how you approach real-world software development scenarios.
**Interviewers look for:** Clear explanations of technical concepts and projects.; Demonstrated problem-solving skills through past experiences.; Understanding of software development lifecycle.; Ability to work collaboratively.; Genuine interest in the company and the role.
**Evaluation criteria:** Depth of understanding of past projects.; Technical decision-making rationale.; Problem-solving approach in previous experiences.; Communication and articulation skills.; Cultural fit and enthusiasm.
**Common rejection reasons:** Inability to explain past projects or technical decisions.; Lack of clarity on contributions to team projects.; Poor understanding of fundamental computer science concepts.; Difficulty in communicating technical ideas.; Mismatch in expectations regarding role or company culture.
## Questions

- Tell me about a challenging bug you encountered and how you debugged it.
- Describe the architecture of a project you worked on. What were the key components?
- How do you ensure the quality of your code?
- What is your experience with version control systems like Git?

## Preparation tips

- Prepare to discuss 2-3 key projects from your resume in detail.
- Think about the technical challenges you faced and how you solved them.
- Be ready for behavioral questions (STAR method is helpful).
- Research the company and understand our values.
- Prepare questions to ask the interviewer.

## Round 3: HR and Cultural Fit Round
**Type:** HR / Cultural Fit Interview · **Difficulty:** Easy · **Duration:** 30 min
Assessing cultural fit, motivation, and career aspirations.
This is typically the first or last round, conducted by HR. It focuses on your background, motivations, career goals, and cultural fit. They will assess your communication skills, enthusiasm for the role and company, and ensure your expectations align with what Hudson River Trading offers. This is also an opportunity for you to ask questions about the company culture, benefits, and the overall employee experience.
**Interviewers look for:** Positive attitude and enthusiasm.; Good communication and interpersonal skills.; Alignment with company culture.; Clear understanding of the role and career goals.; Willingness to learn and contribute.
**Evaluation criteria:** Cultural fit; Motivation and enthusiasm; Communication skills; Alignment with team and company values; Career aspirations
**Common rejection reasons:** Lack of alignment with company culture or values.; Unrealistic salary expectations.; Poor communication or interpersonal skills.; Lack of enthusiasm for the role or company.; Inability to answer basic behavioral or situational questions.
## Questions

- Why are you interested in this role at Hudson River Trading?
- What are your strengths and weaknesses?
- Where do you see yourself in 5 years?
- How do you handle working under pressure?
- Do you have any questions for me?

## Preparation tips

- Be prepared to talk about why you are interested in Hudson River Trading.
- Think about your career goals and how this role fits into them.
- Practice answering common behavioral questions.
- Prepare thoughtful questions to ask the interviewer about the company culture, team, and work environment.
- Dress professionally and maintain a positive attitude.