# Software Engineer
**Role:** Software Engineer · **Level:** L6
**Company:** [Optiver](https://scaleengineer.com/companies/optiver)
**Difficulty:** Hard
**Salary:** US$180000 - US$250000
**Experience:** 5 - 10
**Timeline:** ~14 days
The Software Engineer L6 interview at Optiver is a rigorous process designed to assess candidates' technical expertise, problem-solving abilities, and cultural fit for a senior role. It typically involves multiple rounds focusing on data structures, algorithms, system design, and behavioral aspects, with a strong emphasis on practical application and real-world scenarios.
Canonical: https://scaleengineer.com/interviews/optiver/l6-software-engineer
---
## Overall evaluation

- Technical Proficiency
- System Design & Architecture
- Behavioral & Cultural Fit

## Questions asked

- Design a system to handle real-time stock price updates for millions of users.
- Implement a function to find the k-th largest element in an unsorted array.
- Discuss a time you had to deal with a production issue and how you resolved it.
- How would you design a distributed rate limiter?
- Explain the CAP theorem and its implications for distributed systems.
- What are the differences between processes and threads?
- Describe a challenging technical decision you made and the outcome.
- How do you approach testing complex software systems?
- Design an algorithm to detect cycles in a directed graph.
- What are the trade-offs between monolithic and microservices architectures?

## Preparation tips

### lists

- Thoroughly review data structures and algorithms, focusing on efficiency and common use cases.
- Practice system design problems, considering scalability, reliability, and trade-offs.
- Prepare for behavioral questions by reflecting on past experiences and aligning them with Optiver's values.
- Understand Optiver's business and the specific challenges of the trading industry.
- Practice coding on a whiteboard or in a shared editor to simulate the interview environment.
- Research common interview questions for senior software engineering roles at trading firms.
- Be prepared to discuss your resume in detail, highlighting relevant projects and achievements.

### studyPlan

- {"title":"Data Structures and Algorithms","longDescription":"Weeks 1-2: Focus on core data structures (arrays, linked lists, trees, graphs, hash tables) and algorithms (sorting, searching, dynamic programming, graph traversal). Practice implementing these and analyzing their time/space complexity. Solve LeetCode problems tagged 'Medium' and 'Hard'.","shortDescription":"Weeks 1-2: Data Structures & Algorithms (LeetCode Medium/Hard)."}
- {"title":"System Design","longDescription":"Weeks 3-4: Dive into system design concepts. Study distributed systems, databases (SQL/NoSQL), caching, load balancing, message queues, and microservices. Practice designing common systems like Twitter feed, URL shortener, or a distributed cache. Focus on trade-offs and scalability.","shortDescription":"Weeks 3-4: System Design (Distributed Systems, Databases, Caching)."}
- {"title":"Behavioral Preparation","longDescription":"Week 5: Prepare for behavioral questions. Reflect on your career, identify key projects, leadership experiences, and challenging situations. Use the STAR method (Situation, Task, Action, Result) to structure your answers. Research Optiver's culture and values.","shortDescription":"Week 5: Behavioral Preparation (STAR method, Optiver values)."}
- {"title":"Specialized Topics (if applicable)","longDescription":"Week 6: Focus on low-latency and high-frequency trading concepts if applicable to the specific role or location. Review concurrency, multithreading, and performance optimization techniques. Practice coding problems related to these areas.","shortDescription":"Week 6: Low-Latency & Concurrency (Performance, Multithreading)."}

## Location differences

- {"location":"Amsterdam","differences":{"tips":["Familiarize yourself with common cloud services and their use cases.","Practice designing scalable and resilient systems, considering various failure scenarios.","Be prepared to discuss your experience with leading technical projects and mentoring junior engineers.","Understand the trade-offs involved in different architectural decisions.","Research Optiver's specific technology stack and business domain."],"interviewFocus":["System design and architecture for large-scale, distributed systems.","Deep understanding of distributed systems concepts (consistency, availability, partitioning).","Experience with cloud-native technologies and practices.","Leadership and mentorship capabilities.","Ability to drive technical strategy and decision-making."],"commonQuestions":["How would you design a distributed caching system for a high-traffic e-commerce platform?","Discuss a challenging technical problem you solved in a previous role and your approach.","Explain the trade-offs between different database technologies (SQL vs. NoSQL) for a specific use case.","How do you ensure the scalability and reliability of a microservices architecture?","Describe your experience with cloud platforms (AWS, Azure, GCP) and their services."]}}
- {"location":"Chicago","differences":{"tips":["Master common algorithms and data structures, and be able to analyze their time and space complexity.","Practice coding problems that involve optimization and performance considerations.","Review concepts related to concurrency, threading, and synchronization.","Be prepared to explain your thought process clearly and concisely.","Understand the importance of testing and debugging strategies."],"interviewFocus":["Advanced data structures and algorithms, with a focus on efficiency and complexity.","Performance optimization and low-level system understanding.","Concurrency and multithreading.","Problem-solving and analytical skills.","Ability to write clean, efficient, and maintainable code."],"commonQuestions":["Design an algorithm to detect duplicate files in a large file system.","How would you optimize a slow-performing database query?","Discuss your experience with performance tuning and profiling.","Explain the principles of concurrent programming and common pitfalls.","How do you approach debugging complex issues in a production environment?"]}}
- {"location":"Singapore","differences":{"tips":["Deep dive into low-latency programming techniques and data structures.","Understand the fundamentals of financial markets and trading protocols.","Practice problems related to real-time data processing and event-driven architectures.","Be prepared to discuss your experience with performance-critical applications.","Research Optiver's trading strategies and technology stack."],"interviewFocus":["Low-latency system design and optimization.","Understanding of financial markets and trading systems.","Concurrency and parallelism in high-throughput environments.","Data structures and algorithms optimized for speed.","Risk management and system stability."],"commonQuestions":["How would you design a real-time trading system's matching engine?","Discuss the challenges of low-latency systems and how you've addressed them.","Explain the concepts of market data processing and order management.","How do you ensure data integrity and accuracy in a financial trading environment?","Describe your experience with high-frequency trading (HFT) technologies."]}}

## Round 1: Technical Coding Round 1
**Type:** Data Structures and Algorithms Interview · **Difficulty:** Hard · **Duration:** 45 min
Coding challenge focused on data structures and algorithms.
This round focuses on assessing your core computer science fundamentals. You will be presented with one or two coding problems that require you to implement algorithms and use appropriate data structures. The interviewer will evaluate your ability to understand the problem, devise a solution, write clean code, and analyze its time and space complexity. Expect to code on a whiteboard or a shared online editor.
**Interviewers look for:** Strong analytical and problem-solving skills.; Proficiency in data structures and algorithms.; Ability to write clean, efficient, and bug-free code.; Clear communication of thought process.
**Evaluation criteria:** Problem-solving approach.; Correctness and efficiency of the solution.; Coding style and clarity.; Ability to handle follow-up questions and edge cases.
**Common rejection reasons:** Inability to articulate thought process clearly.; Lack of fundamental data structure and algorithm knowledge.; Poor coding practices (e.g., unreadable code, no error handling).; Difficulty in breaking down complex problems.; Not considering edge cases or constraints.
## Questions

- Given a binary tree, find its inorder traversal.
- Implement a function to find the median of a stream of numbers.
- Find the longest substring without repeating characters.

## Preparation tips

- Practice coding problems on platforms like LeetCode, HackerRank, or Coderbyte.
- Focus on understanding the time and space complexity of your solutions.
- Be prepared to explain your approach and justify your choices.
- Practice coding without an IDE to simulate the interview environment.

## Round 2: System Design Round
**Type:** System Design Interview · **Difficulty:** Hard · **Duration:** 60 min
Design a complex software system, focusing on scalability and reliability.
This round assesses your ability to design and architect complex software systems. You'll be given a high-level problem (e.g., design a social media feed, a URL shortener, or a distributed key-value store) and expected to propose a robust and scalable solution. The focus is on your understanding of distributed systems, databases, caching, APIs, and trade-offs involved in system design.
**Interviewers look for:** Ability to design complex, scalable, and distributed systems.; Deep understanding of system components and their interactions.; Knowledge of various architectural patterns.; Ability to articulate design decisions and trade-offs.
**Evaluation criteria:** System design approach.; Scalability and performance considerations.; Reliability and fault tolerance.; Choice of technologies and justification.; Understanding of trade-offs.
**Common rejection reasons:** Lack of understanding of distributed systems principles.; Inability to design scalable and resilient systems.; Poor consideration of trade-offs.; Not addressing potential failure points.; Vague or incomplete system design.
## Questions

- Design a distributed caching system.
- Design a rate limiter for an API.
- Design a system to process and store real-time sensor data.

## Preparation tips

- Study common system design patterns and architectures.
- Practice designing various systems, focusing on scalability, availability, and performance.
- Understand the strengths and weaknesses of different database technologies.
- Be prepared to discuss trade-offs and justify your design choices.
- Read system design case studies and blogs.

## Round 3: Behavioral and Fit Round
**Type:** Behavioral Interview · **Difficulty:** Medium · **Duration:** 45 min
Behavioral questions to assess cultural fit and past experiences.
This round focuses on your behavioral and cultural fit. You'll be asked questions about your past experiences, how you handle specific situations (e.g., conflicts, failures, successes), your motivations, and your career goals. The interviewer wants to understand how you work in a team, your leadership potential, and whether you align with Optiver's values.
**Interviewers look for:** Evidence of collaboration and teamwork.; Examples of leadership and initiative.; Ability to handle challenging situations and conflicts.; Adaptability and learning mindset.; Passion for technology and the company.
**Evaluation criteria:** Past experiences and accomplishments.; Teamwork and collaboration skills.; Leadership potential.; Problem-solving approach in non-technical contexts.; Cultural fit and alignment with Optiver's values.
**Common rejection reasons:** Lack of clear communication.; Inability to provide specific examples.; Not demonstrating alignment with company values.; Appearing unenthusiastic or disengaged.; Poor conflict resolution or teamwork examples.
## Questions

- Tell me about a time you faced a significant technical challenge and how you overcame it.
- Describe a situation where you had a conflict with a colleague and how you resolved it.
- What are your strengths and weaknesses as a software engineer?
- Why are you interested in working at Optiver?

## Preparation tips

- Prepare specific examples using the STAR method (Situation, Task, Action, Result).
- Reflect on your strengths, weaknesses, and career aspirations.
- Research Optiver's company culture, mission, and values.
- Be ready to discuss why you are interested in Optiver and this specific role.
- Practice articulating your experiences clearly and concisely.

## Round 4: Managerial Round
**Type:** Managerial / Leadership Interview · **Difficulty:** Hard · **Duration:** 60 min
Discuss leadership, strategy, and career goals with the hiring manager.
This final round is typically with the hiring manager or a senior leader. It focuses on your overall experience, leadership potential, strategic thinking, and how you can contribute to the team and company at a senior level. Expect questions about your career goals, how you approach technical leadership, and your vision for software development.
**Interviewers look for:** Ability to lead technical initiatives.; Mentorship and guidance for junior engineers.; Strategic thinking about technology and product.; Strong communication and collaboration skills.; Ownership and accountability.
**Evaluation criteria:** Technical depth and breadth.; Strategic thinking and long-term vision.; Leadership and mentorship capabilities.; Communication and influence.; Alignment with senior engineering expectations.
**Common rejection reasons:** Lack of strategic thinking.; Inability to connect technical solutions to business goals.; Poor communication with stakeholders.; Resistance to feedback or new ideas.; Not demonstrating leadership or ownership.
## Questions

- How would you mentor junior engineers on your team?
- Describe a time you had to influence a technical decision across multiple teams.
- What is your vision for a high-performing engineering team?
- How do you stay updated with the latest technologies and trends?

## Preparation tips

- Think about your career aspirations and how this role aligns with them.
- Prepare examples of leadership, mentorship, and strategic decision-making.
- Be ready to discuss your views on software development best practices and team dynamics.
- Show enthusiasm for the role and the company.
- Ask thoughtful questions about the team, the role, and the company's direction.