Senior Backend Engineer (m/f/d)

Senior Backend Engineer (m/f/d)

As aSenior Backend Engineer, you'll join one of our clients throughMeyer Talent Acquisitionand play a key role in building secure, scalable backend systems for a next-generation digital payments platform.

You'll take ownership of business-critical backend services, helping to design and develop modern, cloud-native applications in a highly regulated environment. Working closely with Engineering, Product, QA, and Compliance teams, you'll contribute across the full software lifecycle—from architecture and implementation to security, scalability, and operational excellence.

This role is ideal for someone who enjoys building high-quality backend systems, taking technical ownership, and working on products where reliability, security, and compliance are at the core of everything you build.

You will work closely with the CTO, Product, QA, and Compliance teams, shaping systems end-to-end - from architecture to implementation - with a strong focus on scalability, auditability, and security.

Your Responsibilities

• Take full ownership of the Fireblocks crypto custody integration, including knowledge transfer from external partners and ongoing development.
• Design and implement secure, auditable integration layers between backend services and external APIs, ensuring full traceability.
• Develop and maintain backend services using Kotlin/Spring Boot, translating product requirements into scalable and maintainable solutions.
• Build and operate RESTful APIs and event-driven architectures (e.g. Kafka), ensuring reliability, fault tolerance, and idempotency.
• Implement secure authentication and authorization flows using OAuth/OIDC-based identity solutions (e.g. Zitadel).
• Apply a compliance-by-design approach across all backend development, ensuring auditability and alignment with regulatory standards.
• Collaborate closely with QA, Security, and Compliance teams to ensure high-quality releases and successful audit outcomes.

Required Qualifications

What You Bring

• 5-8 years of experience as a Backend or Full-Stack Engineer in production environments
• Strong experience with Kotlin or JVM-based languages (Java), as well as Spring Boot and PostgreSQL
• Hands-on expertise with event-driven architectures (e.g. Kafka or similar messaging systems)
• Proven experience designing RESTful APIs and integrating third-party systems
• Solid understanding of OAuth 2.0 / OIDC and identity providers such as Zitadel, Keycloak, or Auth0
• Experience working in regulated environments (e.g. fintech, banking, ISO 27001, PCI-DSS) with a focus on auditability
• Strong ownership mindset and ability to communicate technical concepts to non-technical stakeholders

Core Competencies

• Technical ownership - You take full responsibility for the systems you build and proactively manage risks and dependencies.
• Compliance and security mindset - You embed auditability, traceability, and security into every layer of your work.
• Collaborative engineering - You work closely with cross-functional teams and contribute to a strong engineering culture.
• System thinking - You design scalable, resilient architectures and understand the broader system impact of your work.
• Adaptability - You bring structure and clarity to complex, evolving environments and shifting priorities.