Senior Software Engineer (Backend): Onboarding

This position is listed on behalf of a partner company, which manages all applications and next steps. Our partner is looking for a Senior Software Engineer (Backend): Onboarding based in Spain. This is an opportunity to build and evolve the backend infrastructure that enables businesses and their customers to access secure, compliant financial services. You will join an Onboarding & Identity team responsible for the end-to-end customer verification journey, from initial registration through compliance approval. The platform orchestrates KYC/KYB checks, identity verification, sanctions and PEP screening, customer risk assessments, and agreement signing. You will develop scalable APIs and services that support direct, embedded, and partner-led onboarding at high volumes. Working closely with Product, Engineering, and external technology providers, you will help improve automation while maintaining rigorous regulatory standards. This is a hands-on engineering role in an international, fast-growing environment with a hybrid or remote working approach.