Senior Core Software Engineer – Data & Control

Your role
As a senior engineer, you'll help architect and lead the development of our proprietary trading stack, with a focus on systems related to data infrastructure and control workflows. You'll set the technical direction for high-performance datastores that serve our latency-sensitive trading strategies, help build a world-class data platform underpinning our cutting-edge quantitative research, and design control tools that safeguard our operation and unlock deep insights into our business. This is a role for someone who wants to own and solve complex problems end to end, raise the bar for those around them, and make a lasting impact.

What this role offers you

• Ownership of systems that matter: design, build, and take responsibility for systems from first sketch through production.

• Room to grow: internal and external training on trading software, agile methodologies, and hardware/software management, at a company that grows with your ambitions.

• Direct collaboration with quantitative researchers: translate their needs into robust systems and help shape how they work with data.

• A culture of knowledge sharing: learn from and mentor a team that takes growth seriously.

• Impact without unnecessary complexity: we believe in simplicity; you'll build solutions others can confidently build on.

What you bring

• 5+ years of experience in HPC, large-scale data infrastructure, and/or real-time systems as a software or data engineer, with a track record of owning significant systems from design through production. Prior experience at a trading firm or similar low-latency, data-intensive environment is strongly desired.

• Technical mastery in Python and/or C++, with the judgment to know when each is the right tool. Excellent command of relational databases and their alternatives, and the ability to drill efficiently into data for answers and metrics. Web development skills or proficiency in statistics and/or financial theory are a strong plus.

• Curiosity about the bigger picture: you want to understand what the company needs to succeed and how the trading industry works, so your work stays aligned with what really matters.

• Experience partnering with researchers, translating their needs into robust systems.

• A drive to learn, understand, and continuously improve the systems around you.

• A preference for simplicity: clean solutions, no unnecessary complexity.

• A team-first mindset: you enjoy sharing knowledge and mentoring others.

• Language skills in English and French, written and spoken.

What we offer

• A dynamic work environment with genuine opportunities to grow as the company grows.

• Professional development through internal and external training.

• A personal Swile card for meals in Paris.

• Access to sports facilities.

• Regular team activities and events.

• A collaborative office in the heart of Paris.

• Health insurance fully paid by the company.

• A competitive compensation package, including a bonus scheme.

Application process

1. Apply online — submit your application (in English) through our website.

2. Introductory interview — an online conversation with our recruiter or hiring manager to align on expectations and mutual fit.

3. Technical assessment — a programming challenge to demonstrate your engineering skills.

4. Technical discussion — an in-depth conversation with our engineers on building high-performance systems.

5. Final round — visit our office to meet senior stakeholders, followed by an informal drink to get a feel for the team.

6. Offer — receive our offer and prepare to join WEBB.