Senior Backend Engineer

We're looking for a senior backend engineer to own and evolve our backend architecture. We're building a new platform from the ground up, and you'll design and build the core services that sit between our Flutter frontend and regulated brokerage infrastructure.

This is a high-ownership role. You'll make architectural decisions, ship production systems, and set the engineering standard for the backend. We don't need someone to fill a seat. We need someone who builds systems that hold up under real-world pressure.

What you'll do

• Architect and build backend services in Kotlin
• Design and maintain CI/CD pipelines, testing strategies, and deployment infrastructure.
• Make build-vs-buy and technology decisions for the backend. You'll own these choices.
• Integrate AI agents and LLM-powered workflows into our products and engineering processes. We're building AI-native, not experimenting with it on the side. If you're already designing agentic systems and using AI as a force multiplier, not just an autocomplete, we're aligned.
• Mentor and elevate other engineers. As the team grows, you'll help set the bar for technical quality.

Do you have experience in System design?, Do you have a Master's degree?, You've built and shipped backend systems at scale, ideally in Kotlin or a strong JVM language. You've made architectural decisions that held up under production pressure. Engineers around you have sought out your technical judgement.

You take ownership without being asked. You care about the product, not just the code. You're direct, low-ego, and allergic to unnecessary process.

Technical foundation

• Strong Kotlin or JVM experience. We care about depth of engineering skill, not years on a resume
• Distributed systems design: microservices, event-driven architecture, API design
• Infrastructure: Kubernetes, Docker, CI/CD, infrastructure-as-code
• Databases: relational (PostgreSQL) and NoSQL, with solid data modelling instincts
• Cloud platforms: AWS, GCP, or Azure
• Testing philosophy: not just writing tests, but designing systems that are testable
• English fluency - spoken & written

What sets candidates apart

• Hands-on experience building with AI agents, LLM integrations, or agentic workflows. Not just using Copilot, but architecting AI into products
• Fintech or wealthtech background, especially around brokerage, custody, or regulated financial systems
• A track record of taking something from zero to production and owning the outcome

Be part of a growing team of interdisciplinary experts in fields such as math, software engineering, AI, data science, design and UX. Join us and enjoy:

• An international environment: We have offices in Leuven and are present in many countries in the EU and in other continents.
• Attractive remuneration: We offer a competitive salary and benefits package.
• Self-development: We actively encourage you to join conferences and trainings to improve your knowledge and widen your network.
• Equal opportunity: All qualified applicants will receive consideration for employment without regard to age, race, religion, sex, gender identity or expression.

InvestSuite builds white-label wealthtech infrastructure that connects with broker custodians across regulated financial markets. Our platform powers investment experiences for financial institutions and the backend is the engine that makes it all work.