Quantitative Developer
Do you want to build a platform that powers real trading?
We are looking for a Quantitative Developer to join De Facto Traders. In this role, you’ll design and build the core systems that make trading possible - from data ingestion to order execution. Your code will run in production every trading day. Your architectural decisions will shape how we scale. Your systems will be the foundation that our traders and researchers rely on.
You’ll work within our technology team in a small, flat organization, building and operating the infrastructure that powers everything we do. You’ll collaborate closely with traders and quantitative researchers - the people who use your systems sit next to you, so you’ll hear immediately when something breaks or works brilliantly.
About De Facto Traders
De Facto Traders is a Danish proprietary trading firm founded in 2017, located in a modern office in central Aarhus. We trade systematic equity strategies using our own capital, with a focus on technology and quantitative analysis. Without external clients, our work centers on research, systems, and execution.
We are a specialized firm that builds our own trading infrastructure. We believe building rather than buying gives us an edge - our trading platform, analytics tools, and data infrastructure are developed in-house. We embrace modern development practices and tooling, including AI assistants integrated into our daily workflows.
In a small team, your work has real impact. You’ll have ownership, solve interesting technical problems, and work with colleagues who take their craft seriously. You’ll see the results of your efforts every trading day.
The Role
You’ll focus on building and maintaining our core trading infrastructure.
Platform development - Design and build the systems that power our trading operations. Real-time data processing, order management and position tracking.
Architecture & design - Make decisions that shape how our systems evolve. Balance reliability, performance, and maintainability.
Data infrastructure - Build and maintain real-time pipelines that move data from external sources into our trading systems and analytics tools.
Operational excellence - Own what you build. Monitor, debug, and improve systems in production.
Your Qualifications
This role requires someone who can design and build systems that work reliably under pressure.
Software engineering expertise - You write clean, maintainable code. You understand trade-offs between different approaches and can defend your choices.
Systems & real-time thinking - You can architect solutions that handle complexity under pressure. You think about failure modes, scaling, concurrency, and distributed systems.
Data engineering skills - You can build data pipelines, work with databases, and handle messy real-world data.
Market awareness - Understanding how trading systems work, data pipelines, and how orders execute.
Experience - 5+ years in software development, preferably in environments where reliability matters.
If you’re missing one of these but exceptionally strong in others, we’d still like to hear from you.
Your Working Style
Technical skills matter, but how you work matters just as much. You communicate clearly, translating technical concepts for non-technical colleagues and turning business needs into robust solutions.
Our values guide how we work - and we’re looking for someone who shares them.
Ambition - You’re always raising the bar. You don’t settle for “good enough” when better is possible.
Curiosity - You dig into systems to understand what’s really happening. You question assumptions and update your views.
Grit - You stay focused and push through obstacles. You can move forward without having everything fully defined upfront.
Ownership - You gather requirements, prioritize ruthlessly, ship things, and iterate. You don’t wait to be told what to do.
How to Apply
Send your application to Simon Søllingvraa at sso@defactotraders.com including:
- Your CV showing relevant software engineering experience
- A brief cover letter explaining why this role appeals to you
You will receive confirmation when your application is received. We accept applications until March 1, 2026, and will evaluate applications on an ongoing basis. After the deadline, we will invite selected candidates for interviews.
