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Senior Software Engineer / Team Lead (API & Platform)

  • Hybrid
    • Utrecht, Utrecht, Netherlands
  • Development

As a Senior Software Engineer / Team Lead at Roseman Labs, you will design and develop the APIs. SDKs and backend system powering privacy-preserving analytics. If this interests you, then apply!

Job description

As a Senior Software Engineer and Team Lead at Roseman Labs, you will help build the foundation of a platform used in high-impact domains such as Financial Services and National Security, while guiding and mentoring a small team of engineers. You will design and develop the APIs, SDKs, and backend systems that power privacy-preserving analytics, while also occasionally developing front-end components that make these capabilities intuitive to use. You’ll work with TypeScript for SDK and backend development, and collaborate on APIs and services written in Rust, C++, and Python. 

If you enjoy working across the stack but thrive most in backend and API architecture, this role is for you. 

About us

At Roseman Labs, we are pioneering a trust-by-design platform that turns siloed data into collective intelligence - enabling secure, multi-party analytics without ever exposing sensitive data. 

We use Multi-Party Computation (MPC), an advanced cryptographic technique that ensures data remains encrypted at rest, in transit, and in use. With Roseman Labs, banks can jointly detect fraud patterns across institutions, and government agencies can combine intelligence sources without compromising confidentiality. 

Having recently closed a €5M Series A (€10M total funding), we are scaling our platform for integrators and partners through an API-first approach, expanding across Defense, Financial Services, and critical-infrastructure sectors. 

The role

We are looking for a Senior Software Engineer and Team Lead to help shape our API-first architecture and bring advanced cryptography to developers and end users, while coordinating team efforts and ensuring technical excellence. 

As part of our development team, you will build core backend services and SDKs, while also developing front-end components that expose these capabilities in clear and usable ways. You will lead a team of three developers while remaining hands-on, spending around 70% of your time coding. 

You will work closely with cryptography engineers, DevOps, and designers to turn complex technology into elegant, secure, and scalable software. Your expertise should lean toward backend systems and API design, but you are comfortable contributing across the stack to ensure seamless end-to-end delivery. 

Our core languages across teams include TypeScript, Rust, and Python, with this role you will work with TypeScript for backend SDK and API development and collaborate on APIs and services written in Rust, C++, and Python.


Your responsibilities

  • Lead and mentor a small team of engineers, ensuring smooth collaboration, clear priorities and timely delivery to achieve product goals. 

  • Design and implement scalable APIs, SDKs, and backend services for developers and partners 

  • Occasionally develop front-end components and interfaces that make cryptography and data collaboration accessible 

  • Shape and evolve our API-first architecture for integration and modularity 

  • Build and document end-to-end product features spanning backend logic, API endpoints, and UI layers 

  • Review code and guide architectural decisions. 

  • Collaborate with UX, DevOps, and cryptography teams to deliver secure and intuitive workflows 

  • Stay current with trends in web architecture, developer experience, and secure software design 

Job requirements

What you bring

  • 5+ years of professional experience as a Full-Stack or Backend-leaning Engineer 

  • Experience in a leadership or team lead role, with the ability to guide and mentor developers 

  • Proven experience designing and maintaining APIs (REST or GraphQL) and SDKs 

  • Proven experience building backend systems and SDKs in TypeScript (Node.js, NestJS, or similar) 

  • Experience with frontend frameworks such as Angular or React is a plus — our primary focus is backend and SDK development in TypeScript, though you may occasionally contribute to frontend components 

  • Comfortable working with or integrating APIs written in other languages (e.g. Rust, Python, or C++) 

  • Interest in distributed systems and privacy-enhancing technology 

  • Experience with SQL and NoSQL databases 

  • Understanding of software architecture, scalability, and system design 

  • Ability to work across backend and frontend while keeping API quality and performance top-of-mind 

  • Strong communication and collaboration skills 

  • Professional fluency in English 

  • Comfortable working in a fast-paced, high-impact startup environment 

What we offer

  • Competitive salary 

  • Employee incentive plan 

  • Hybrid working options 

  • Opportunities for professional growth and specialization 

  • A collaborative and inclusive culture 

  • Commute travel expenses covered 

  • Retirement benefits (pension) 

  • Regular team activities and events 

  • Flat organization structure 

  • Work on complex and meaningful technical challenges in an emerging field that combines cryptography, data security, and distributed computing. 

  • The chance to contribute to our mission: enabling privacy-preserving collaboration in finance, national security, and critical infrastructure 

Applying for this role

  • Currently, this position is open for candidates with an EU work permit that are based in The Netherlands

  • When applying for this role, please include links that highlight your relevant experience, such as GitHub, Stack Overflow, or portfolio websites

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