Senior C# UI Engineer – Trading Systems

📍 Job Overview

Job Title: Senior C# UI Engineer – Trading Systems Company: Optiver Location: Amsterdam, North Holland, Netherlands Job Type: Full-Time Category: Software Engineering / Trading Systems Development Date Posted: 2025-11-03 Experience Level: Senior (5-10 years estimated) Remote Status: On-site

🚀 Role Summary

• Focus on designing and developing high-performance, real-time User Interfaces (UIs) for global trading and research platforms.
• Leverage and extend an in-house, high-performance C# framework to build robust applications for traders and quantitative researchers.
• Collaborate at the intersection of C#, C++, and real-time data to deliver world-class, low-latency applications.
• Drive technical leadership in UI development, focusing on performance optimization and architectural design.

📝 Enhancement Note: The role is specifically for a Senior C# UI Engineer within the Trading Systems domain. This implies a focus on high-frequency trading environments, demanding exceptional performance, low latency, and robust application architecture. The emphasis on an "in-house, high-performance C# framework" suggests a need for engineers who can not only utilize but also contribute to the evolution of core development tools, requiring a blend of application development and framework extension skills.

📈 Primary Responsibilities

• Design, develop, and implement high-performance UI applications using C# within Optiver’s proprietary in-house framework.
• Extend and enhance the core UI framework to improve usability, performance, and flexibility for a broader development team.
• Integrate seamlessly with complex C++ backend microservices, ensuring efficient data flow, real-time updates, and API consistency.
• Architect scalable, modular UI components capable of handling large data volumes and real-time updates effectively.
• Collaborate closely with traders, quantitative researchers, and fellow engineers to translate user needs into effective, reliable, and fast solutions.
• Provide technical leadership, mentor junior engineers, conduct code reviews, and champion engineering best practices within the UI development team.
• Innovate and drive improvements in performance optimization, system architecture, and development tooling to scale the UI ecosystem.

📝 Enhancement Note: The responsibilities highlight a dual focus: direct application development using the existing framework and contributing to the framework itself. This indicates a senior-level role requiring not just coding proficiency but also architectural vision and leadership. The integration with C++ backend microservices is a critical aspect, implying a need for strong inter-process communication (IPC) and interop understanding.

🎓 Skills & Qualifications

Education: While not explicitly stated, a Bachelor's or Master's degree in Computer Science, Software Engineering, or a related technical field is generally expected for senior engineering roles in quantitative finance.

Experience: 5-10 years of professional software development experience, with a significant focus on C# UI development and system architecture.

Required Skills:

• Expert proficiency in C# and the .NET ecosystem, with a proven track record of building high-performance desktop applications (e.g., WPF, WinForms, or custom frameworks).
• Strong understanding of C++ and the ability to effectively interoperate with C++ services and APIs.
• Demonstrated experience in designing, building, and maintaining complex software frameworks and modular UI systems.
• Deep knowledge of multithreading, concurrency patterns, and real-time data processing techniques.
• Proven ability to lead technical initiatives, guide other developers, and make sound architectural decisions.
• Excellent problem-solving skills, with the capacity to operate effectively in a fast-paced, highly collaborative environment.

Preferred Skills:

• Experience contributing to internal developer tools, frameworks, or Software Development Kits (SDKs) used across multiple teams.
• Experience designing low-latency data visualizations or working with distributed systems and networked applications.
• Hands-on experience with C++/CLI, inter-process communication (IPC), or native interop between C# and C++.
• Familiarity with financial trading systems, quantitative research platforms, or real-time analytics applications.

📝 Enhancement Note: The distinction between required and preferred skills emphasizes the core need for C#/.NET expertise and C++ interoperability, while suggesting that domain-specific financial experience is a bonus rather than a prerequisite. The emphasis on framework development and technical leadership points towards candidates with a strong architectural background.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• Demonstrations of complex C# desktop applications with a focus on performance, responsiveness, and efficient data handling.
• Examples of contributions to software frameworks, libraries, or internal tools that improved developer productivity or system capabilities.
• Case studies detailing how you architected or significantly improved modular UI systems, highlighting scalability and maintainability.
• Evidence of experience with real-time data processing, multithreading, and concurrency management in practical applications.

Process Documentation:

• Ability to document complex UI architectures, framework designs, and integration patterns with backend services.
• Experience in creating and maintaining technical specifications for UI components and framework extensions.
• Proficiency in outlining development workflows, testing strategies, and performance tuning methodologies for UI applications.

📝 Enhancement Note: While a formal "portfolio" might not be explicitly requested in a traditional sense, candidates are expected to demonstrate their capabilities through past projects and experience. The emphasis should be on showcasing architectural thinking, framework contributions, and hands-on experience with high-performance, real-time systems, particularly those involving C# and C++ interaction.

💵 Compensation & Benefits

Salary Range: Based on industry benchmarks for Senior C# UI Engineers in Amsterdam with 5-10 years of experience in financial technology, a competitive annual salary range is estimated to be €90,000 - €130,000. This range can vary based on specific experience, interview performance, and Optiver's internal compensation structure.

Benefits:

• Performance-based bonus structure tied to global profit pool.
• 25 paid vacation days in the first year, increasing to 30 from the second year.
• Comprehensive training and continuous learning opportunities, including access to conferences and tech events.
• Discounts on health insurance.
• Fully paid first-class commuting expenses.
• Extensive office perks: complimentary breakfast, lunch, and dinner; world-class barista coffee; in-house physio and chair massages; organized sports and leisure activities; and Friday afternoon drinks.
• Competitive relocation packages and visa sponsorship for expats.

Working Hours: The typical working hours are 40 hours per week, but the fast-paced nature of trading systems may necessitate flexibility and occasional extended hours to meet critical deadlines or address urgent market-related issues.

📝 Enhancement Note: Salary estimation is based on available data for similar senior engineering roles in Amsterdam's tech and finance sectors. The benefits package is extensive, reflecting Optiver's commitment to employee well-being and professional development, particularly in a demanding trading environment. The explicit mention of visa sponsorship is a significant benefit for international candidates.

🎯 Team & Company Context

🏢 Company Culture

Industry: Financial Technology, High-Frequency Trading, Market Making. Optiver operates in a highly competitive and dynamic sector, requiring precision, speed, and continuous innovation. Company Size: Optiver is a large global organization with multiple offices worldwide, employing a significant number of professionals. This implies a structured environment with established processes but also opportunities for impact within specialized teams. Founded: Optiver was founded in 1986, bringing decades of experience and a deep understanding of financial markets. This long history suggests a stable yet evolving company culture that values expertise and long-term vision.

Team Structure:

• The UI Engineering team is likely part of a larger Technology department, composed of specialized groups focusing on different aspects of trading systems (e.g., C++ backend, quantitative research tools, infrastructure).
• Reporting structure typically involves a Team Lead or Engineering Manager, with senior engineers expected to mentor and guide more junior members.
• Cross-functional collaboration is critical, involving close partnerships with traders, quantitative researchers, and other engineering disciplines to ensure the trading platforms meet stringent performance and functional requirements.

Methodology:

• Data-driven decision-making is paramount, with a strong emphasis on performance metrics, latency measurements, and reliability testing.
• Agile methodologies are likely employed for iterative development, allowing for rapid adaptation to market changes and user feedback.
• A culture of continuous improvement permeates development practices, from code quality and testing to architectural design and tooling.

Company Website: https://optiver.com/

📝 Enhancement Note: Optiver's position as a leading global market maker signifies a high-stakes environment where technological excellence directly translates to business success. The culture is expected to be performance-oriented, collaborative, and deeply rooted in technical expertise, particularly concerning low-latency systems and quantitative finance.

📈 Career & Growth Analysis

Operations Career Level: This role is positioned as "Senior," indicating a level of technical expertise, architectural contribution, and leadership expectation. Senior engineers are expected to tackle complex problems independently, mentor others, and influence technical direction within their domain.

Reporting Structure: The Senior C# UI Engineer will likely report to a Technology Lead or Engineering Manager responsible for trading system UIs. They will work closely with a dedicated team of engineers, product managers, and stakeholders from trading and research departments.

Operations Impact: The work directly impacts the speed, efficiency, and effectiveness of Optiver's trading and research operations. High-performance, intuitive UIs are critical for traders to make rapid, informed decisions in fast-moving markets, directly influencing the firm's profitability and competitive edge.

Growth Opportunities:

• Technical Specialization: Deepen expertise in C#, C++ interoperability, high-performance computing, and low-latency systems architecture.
• Framework Development: Transition into roles focused on architecting and leading the development of core internal frameworks and developer tools.
• Team Leadership: Move into management roles such as Tech Lead, Engineering Manager, or Architect, overseeing larger teams and strategic technical initiatives.
• Cross-Domain Exposure: Gain exposure to other areas of trading technology, such as C++ backend development, algorithmic trading strategies, or infrastructure.

📝 Enhancement Note: The career path for a Senior Engineer at a firm like Optiver typically involves deepening technical mastery and taking on increasing responsibility for architectural decisions and team guidance. The "operations" in this context refers to the operational efficiency and effectiveness of the trading systems themselves, driven by the engineering team.

🌐 Work Environment

Office Type: This is an on-site role in a modern, well-equipped office environment in Amsterdam. Optiver offices are known for fostering collaboration and providing excellent amenities.

Office Location(s): Amsterdam, North Holland, Netherlands. This location is a major financial and technological hub in Europe.

Workspace Context:

• The workspace is designed for collaboration, with an emphasis on team interaction and knowledge sharing.
• Access to state-of-the-art hardware, software, and development tools is standard.
• The environment is fast-paced and intellectually stimulating, attracting top talent from around the globe.
• Expect close proximity and regular interaction with traders, quantitative researchers, and fellow engineers, fostering a dynamic problem-solving culture.

Work Schedule: The standard work week is 40 hours, but the nature of trading demands flexibility. While core hours will exist, there may be periods requiring extended work to support critical system deployments, market events, or urgent issue resolution.

📝 Enhancement Note: The on-site requirement in Amsterdam underscores the importance of immediate collaboration, real-time problem-solving, and the culture of a trading floor environment, where quick communication and proximity are often key.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Screening: A recruiter or hiring manager will review your application and conduct an initial phone screen to assess fit and experience.
• Technical Assessments: Expect coding challenges and technical interviews focusing on C#, C++, data structures, algorithms, multithreading, and systems design. These will likely be conducted remotely or on-site.
• On-site/Virtual Interviews: Multiple rounds of interviews with engineering team members, potential peers, and team leads. These will delve deeper into your technical expertise, problem-solving approach, and architectural thinking.
• System Design/Architectural Discussion: A significant portion will involve discussing your experience with designing complex systems, frameworks, and high-performance UIs. Be prepared to present and defend design choices.
• Cultural Fit & Behavioral: Interviews to assess your fit with Optiver's collaborative and performance-driven culture.

Portfolio Review Tips:

• Highlight Framework Contributions: If you have built or significantly contributed to internal frameworks, SDKs, or development tools, prepare to discuss the architecture, challenges, and impact.
• Showcase Performance Optimizations: Prepare detailed examples of how you've optimized C# applications for performance, especially in scenarios involving real-time data or heavy computation. Quantify the improvements (e.g., latency reduction, throughput increase).
• Demonstrate C#/C++ Interop: If you have experience bridging C# and C++, showcase specific projects or techniques used, such as C++/CLI, P/Invoke, or COM interop.
• Architectural Design: Be ready to walk through the design of a complex UI system you've worked on. Focus on modularity, scalability, maintainability, and how you handled real-time data streams.
• Problem-Solving Case Studies: Prepare to discuss challenging problems you've solved, outlining your thought process, the solutions implemented, and the outcomes.

Challenge Preparation:

• Coding Proficiency: Revisit C# fundamentals, common data structures, algorithms, and multithreading primitives. Practice coding problems similar to those found on platforms like LeetCode (medium-hard difficulty).
• System Design: Study patterns for building scalable, performant, and maintainable UI applications. Consider how to handle real-time data feeds, minimize latency, and manage complex state.
• C++ Interoperability: Refresh your understanding of C++ concepts, especially those relevant to interfacing with .NET, such as memory management and object models.
• Trading System Concepts: Familiarize yourself with basic concepts of financial markets, trading, and low-latency requirements, though deep domain expertise isn't mandatory.

📝 Enhancement Note: The application process emphasizes technical depth, architectural acumen, and hands-on problem-solving. Candidates should be prepared to demonstrate their ability to design, build, and optimize complex systems, particularly those involving high-performance C# and C++ integration.

🛠 Tools & Technology Stack

Primary Tools:

• C# / .NET: Core language and framework for UI development. Proficiency with recent .NET versions is expected.
• WPF/WinForms (or similar desktop UI frameworks): Experience with established .NET UI technologies.
• Proprietary C# UI Framework: Candidates will need to quickly learn and contribute to Optiver's in-house framework.
• C++: Essential for understanding and integrating with backend services.
• Visual Studio: Standard IDE for C# development.

Analytics & Reporting:

• While not directly the focus, understanding how UI performance data is collected and analyzed (e.g., profiling tools, logging frameworks) will be beneficial.

CRM & Automation:

• Not directly applicable to this role, as it's focused on core engineering of trading systems rather than sales or marketing operations. Integration tools might be relevant if the UI system interacts with other enterprise systems.

📝 Enhancement Note: The technology stack heavily emphasizes C#/.NET and C++. The key differentiator is the use of Optiver's proprietary UI framework, meaning candidates must demonstrate strong foundational programming and architectural skills that allow for rapid adaptation to new, specialized tools.

👥 Team Culture & Values

Operations Values:

• Excellence & Precision: A commitment to high-quality, performant, and reliable software is paramount in the trading industry.
• Collaboration & Teamwork: Success hinges on effective communication and teamwork across diverse technical and business functions.
• Innovation & Continuous Improvement: A drive to constantly enhance systems, processes, and individual skills is essential in a rapidly evolving market.
• Problem-Solving: A proactive and analytical approach to tackling complex technical challenges.
• Ownership & Accountability: Taking responsibility for projects, from design through implementation and maintenance.

Collaboration Style:

• Open communication and knowledge sharing are encouraged.
• Expect cross-functional teams working closely together on projects with clear objectives.
• A culture that values constructive feedback and continuous learning from both successes and failures.

📝 Enhancement Note: Optiver's culture is likely to be highly driven by performance, intellectual curiosity, and a shared goal of market excellence. Engineers are expected to be proactive, collaborative, and dedicated to delivering cutting-edge technology in a demanding environment.

⚡ Challenges & Growth Opportunities

Challenges:

• Low-Latency Demands: Meeting the stringent performance requirements of a high-frequency trading environment presents a constant technical challenge.
• Framework Evolution: Contributing to and extending a proprietary, complex UI framework requires deep understanding and careful architectural planning.
• C++ Integration Complexity: Seamlessly integrating C# UIs with high-performance C++ backend services can be technically demanding.
• Fast-Paced Market: Adapting to rapidly changing market conditions and trader requirements necessitates agility and quick problem-solving.

Learning & Development Opportunities:

• Advanced C# & .NET: Deepen expertise in high-performance .NET development, memory management, and concurrency.
• C++ Mastery: Enhance understanding of C++ for more effective integration and collaboration with backend teams.
• System Architecture: Develop skills in designing large-scale, distributed, and real-time systems.
• Financial Markets: Gain in-depth knowledge of trading strategies, market dynamics, and the specific needs of traders and researchers.
• Leadership & Mentorship: Develop leadership skills through mentoring junior engineers and leading technical initiatives.

📝 Enhancement Note: The role offers significant challenges that are directly tied to opportunities for advanced technical and professional growth within a specialized and high-impact field.

💡 Interview Preparation

Strategy Questions:

• Technical Depth: Be prepared to discuss specific C#/.NET features related to performance, concurrency, and UI rendering (e.g., async/await, TPL, GC, UI virtualization).
• Architectural Design: Explain your process for designing scalable UI applications. How would you architect a real-time data dashboard that needs to handle thousands of updates per second? Discuss trade-offs.
• C++ Interoperability: How would you design an API for C# to consume data from a C++ service efficiently? Discuss potential pitfalls and solutions (e.g., marshaling, memory handling).
• Problem-Solving Scenarios: Expect questions that require you to debug complex issues or propose solutions for performance bottlenecks. Think about how you would diagnose and fix a UI that is becoming unresponsive.

Company & Culture Questions:

• Motivation for Trading Systems: Why are you interested in working in the financial trading industry, specifically on UI development?
• Collaboration Experience: Describe a time you worked closely with non-technical stakeholders (like traders or researchers) to deliver a technical solution.
• Mentorship: How have you mentored junior engineers or contributed to team knowledge sharing?
• Handling Pressure: How do you manage your workload and maintain focus in a high-pressure, fast-paced environment?

Portfolio Presentation Strategy:

• Focus on Impact: For each project presented, clearly articulate the problem, your solution, the technologies used, and the quantifiable impact (e.g., performance gains, efficiency improvements, user satisfaction).
• Technical Architecture: Be ready to draw diagrams and explain the architectural choices, design patterns, and trade-offs made.
• C# & C++ Specifics: Highlight any projects where you demonstrated strong C# UI development skills or C++ interoperability.
• Framework Contributions: If applicable, showcase your contributions to internal tools or frameworks, emphasizing how they benefited other developers or the system as a whole.

📝 Enhancement Note: Interview preparation should focus on demonstrating not just coding ability but also architectural foresight, strong C#/.NET and C++ integration skills, and the capacity to thrive in a demanding, performance-critical environment.

📌 Application Steps

To apply for this Senior C# UI Engineer position:

• Submit your application directly through the Optiver careers portal via the provided link.
• Resume Optimization: Tailor your resume to highlight your experience with high-performance C#/.NET desktop applications, C++ interoperability, framework development, and any experience in low-latency or real-time systems. Quantify achievements wherever possible.
• Portfolio Preparation: Prepare concise case studies or detailed descriptions of your most relevant projects. Focus on architectural design, performance optimizations, and any contributions to development frameworks or tools.
• Technical Preparation: Brush up on C#/.NET fundamentals, data structures, algorithms, multithreading, and system design principles. Practice coding challenges and be ready to discuss complex technical scenarios.
• Company Research: Understand Optiver’s role in the market, their technology focus on high-performance systems, and their commitment to innovation and collaboration.

⚠️ Important Notice: This enhanced job description includes AI-generated insights and operations industry-standard assumptions. All details should be verified directly with the hiring organization before making application decisions.