# Software Engineer
**Role:** Software Engineer · **Level:** P7.1
**Company:** [OKX](https://scaleengineer.com/companies/okx)
**Difficulty:** High
**Salary:** US$150000 - US$200000
**Experience:** 7 - 10
**Timeline:** ~14 days
This interview process is for a Software Engineer position at OKX, specifically at the P7.1 level. It is designed to assess a candidate's technical proficiency, problem-solving skills, system design capabilities, and cultural fit within the company.
Canonical: https://scaleengineer.com/interviews/okx/p7.1-software-engineer
---
## Overall evaluation

- Technical Skills
- Problem Solving
- System Design
- Behavioral & Communication

## Questions asked

- Tell me about a time you had to deal with a difficult stakeholder. How did you manage the situation?
- Design a URL shortening service like bit.ly.
- What are the trade-offs between SQL and NoSQL databases?
- How would you optimize the performance of a web application?
- Describe a situation where you disagreed with your manager. What did you do?
- Design a system to handle real-time stock price updates for a trading platform.
- What is your experience with asynchronous programming?
- How do you stay updated with the latest technologies?
- Tell me about a project you are particularly proud of and why.
- How would you design a distributed rate limiter?

## Preparation tips

### lists

- Review core computer science fundamentals (data structures, algorithms, operating systems, databases).
- Practice coding problems on platforms like LeetCode, HackerRank, focusing on medium to hard difficulty.
- Study system design principles and common patterns for scalable applications.
- Prepare to discuss your past projects in detail, focusing on your contributions and technical challenges.
- Research OKX's business, products, and recent news to understand our context.
- Prepare questions to ask the interviewer about the role, team, and company culture.
- Brush up on behavioral interview techniques using the STAR method (Situation, Task, Action, Result).

### studyPlan

- {"title":"Data Structures and Algorithms","longDescription":"Weeks 1-2: Focus on Data Structures and Algorithms. Cover arrays, linked lists, trees, graphs, hash tables, heaps, sorting, searching, dynamic programming, and greedy algorithms. Practice implementing these and analyzing their time and space complexity. Aim for 5-7 problems per day.","shortDescription":"Weeks 1-2: Data Structures & Algorithms (DSA). Practice 5-7 problems daily."}
- {"title":"System Design","longDescription":"Weeks 3-4: Dive into System Design. Study concepts like load balancing, caching, database sharding, message queues, CAP theorem, microservices architecture, API design, and concurrency. Review common system design interview questions and practice designing systems.","shortDescription":"Weeks 3-4: System Design. Study core concepts and practice designing systems."}
- {"title":"Behavioral Preparation","longDescription":"Week 5: Behavioral and Behavioral Questions. Prepare stories using the STAR method for common behavioral questions related to teamwork, leadership, conflict resolution, and handling failure. Reflect on your career experiences and identify key achievements.","shortDescription":"Week 5: Behavioral Prep. Use STAR method for common questions."}
- {"title":"Final Preparation","longDescription":"Week 6: Company Research and Mock Interviews. Research OKX's mission, values, products, and recent news. Conduct mock interviews (technical and behavioral) with peers or mentors to simulate the interview environment and get feedback.","shortDescription":"Week 6: Research OKX & Mock Interviews."}

## Location differences

- {"location":"Singapore","differences":{"tips":["Be prepared to discuss specific examples of systems you've designed or significantly contributed to.","Familiarize yourself with OKX's tech stack and recent projects.","Showcase your ability to think about trade-offs in system design.","Highlight any experience with financial technology or blockchain-related systems."],"interviewFocus":["Deep dive into distributed systems and microservices architecture.","Emphasis on practical experience with large-scale systems.","Assessment of leadership potential and team collaboration.","Understanding of operational excellence and SRE principles."],"commonQuestions":["How would you design a distributed caching system for a high-traffic e-commerce platform?","Describe a challenging technical problem you solved recently and the impact it had.","How do you ensure the scalability and reliability of microservices?","What are your strategies for mentoring junior engineers?","Discuss your experience with cloud-native architectures (e.g., Kubernetes, Docker)."]}}
- {"location":"Remote","differences":{"tips":["Prepare to discuss your understanding of financial markets and trading systems.","Be ready to explain complex algorithms and data structures relevant to finance.","Demonstrate a strong grasp of security principles and their application.","Showcase any contributions to open-source projects in the FinTech domain."],"interviewFocus":["Focus on real-time data processing and low-latency systems.","Evaluation of expertise in financial trading systems and protocols.","Assessment of understanding of security best practices in financial applications.","Exploration of innovative thinking in the FinTech space."],"commonQuestions":["Design an API gateway for a large-scale financial trading platform.","How would you approach performance optimization for a latency-sensitive application?","Discuss your experience with data streaming technologies (e.g., Kafka, Flink).","How do you handle incident management and post-mortems?","What are your thoughts on the future of decentralized finance (DeFi) and its technical implications?"]}}

## Round 1: Technical Coding Round 1
**Type:** Data Structures and Algorithms Interview · **Difficulty:** High · **Duration:** 60 min
Assess fundamental coding skills and algorithmic thinking through problem-solving.
This round focuses on your fundamental computer science knowledge, particularly data structures and algorithms. You will be asked to solve coding problems, often involving algorithmic challenges. The interviewer will assess your ability to analyze problems, devise efficient solutions, write clean and maintainable code, and explain your reasoning clearly. Expect questions that test your understanding of time and space complexity.
**Interviewers look for:** Strong grasp of data structures and algorithms.; Ability to translate requirements into working code.; Logical thinking and systematic approach to problem-solving.; Clear communication of thought process.
**Evaluation criteria:** Correctness of the solution; Efficiency of the solution (time and space complexity); Code quality and readability; Ability to test the code; Problem-solving approach
**Common rejection reasons:** Lack of fundamental knowledge in core CS concepts.; Inability to write clean, efficient, and bug-free code.; Poor problem-solving approach.; Difficulty in explaining thought process.
## Questions

- Given an array of integers, find the contiguous subarray with the largest sum.
- Implement a function to reverse a linked list.
- Find the k-th smallest element in a binary search tree.
- Given a string, find the length of the longest substring without repeating characters.

## Preparation tips

- Practice coding problems on platforms like LeetCode, HackerRank, focusing on medium to hard difficulty.
- Review common algorithms and data structures.
- Practice explaining your thought process out loud while coding.
- Be prepared to discuss trade-offs of different approaches.

## Round 2: System Design Round
**Type:** System Design Interview · **Difficulty:** High · **Duration:** 60 min
Assess ability to design scalable and robust systems.
This round evaluates your ability to design and architect complex systems. You will be presented with a high-level problem (e.g., design a social media feed, a ride-sharing service, or a distributed cache) and expected to propose a scalable, reliable, and maintainable solution. Focus on identifying core components, data models, APIs, and addressing potential bottlenecks and failure points.
**Interviewers look for:** Experience in designing complex, large-scale systems.; Knowledge of distributed systems principles.; Ability to think critically about system components and interactions.; Clear communication of design choices and justifications.
**Evaluation criteria:** Scalability of the proposed design; Reliability and fault tolerance; Clarity and completeness of the design; Understanding of trade-offs; Ability to handle various constraints and requirements
**Common rejection reasons:** Inability to design scalable and reliable systems.; Lack of understanding of distributed system concepts.; Poor trade-off analysis.; Not considering edge cases or failure scenarios.
## Questions

- Design a system like Twitter's news feed.
- Design a distributed key-value store.
- How would you design a rate limiter for an API?
- Design a system to process and store real-time analytics data.

## Preparation tips

- Study common system design patterns and architectures.
- Practice designing various types of systems.
- Understand concepts like CAP theorem, load balancing, caching strategies, and database choices.
- Be prepared to discuss trade-offs between different design decisions.

## Round 3: Behavioral and Managerial Round
**Type:** Behavioral Interview · **Difficulty:** Medium · **Duration:** 45 min
Assess cultural fit, teamwork, and past experiences.
This round focuses on your behavioral aspects, past experiences, and how you fit into the team and company culture. You'll be asked questions about your strengths, weaknesses, how you handle specific situations (e.g., conflict, failure, success), and your career aspirations. Use the STAR method (Situation, Task, Action, Result) to provide structured and impactful answers.
**Interviewers look for:** Evidence of collaboration and teamwork.; Ability to handle conflict and challenges constructively.; Proactiveness and ownership.; Alignment with OKX's values.; Passion for technology and the company's mission.
**Evaluation criteria:** Communication clarity; Teamwork and collaboration skills; Problem-solving approach in past experiences; Leadership potential; Cultural fit with OKX
**Common rejection reasons:** Poor communication skills.; Lack of self-awareness.; Inability to provide specific examples.; Not aligning with company values or team dynamics.; Lack of enthusiasm or interest.
## Questions

- Tell me about a time you failed. What did you learn from it?
- Describe a situation where you had to work with a difficult team member. How did you handle it?
- What are your strengths and weaknesses?
- Why are you interested in working at OKX?
- Describe a time you took initiative to improve a process or product.

## Preparation tips

- Prepare specific examples using the STAR method for common behavioral questions.
- Reflect on your career goals and why you are interested in OKX.
- Be ready to discuss your leadership style and how you collaborate.
- Show enthusiasm and genuine interest in the role and company.