Senior Software Engineer (Backend): Onboarding en España, España

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.

Accountabilities

• Design, build, and operate reliable backend services supporting the complete customer onboarding and identity verification journey.

• Develop and maintain APIs and orchestration capabilities for KYC/KYB, identity verification, sanctions and PEP screening, automated customer risk assessments, and agreement signing.

• Contribute to onboarding solutions for direct business customers, embedded payment partners, and the underlying customers of licensed partners.

• Build scalable integration capabilities that enable partners to onboard large volumes of end customers through APIs and webhooks.

• Collaborate closely with Product Managers and engineers within the Embedded Payments and Onboarding squad to deliver high-quality solutions and iterate efficiently.

• Integrate third-party identity verification and regulatory technology providers, including solutions such as SumSub and Orbis, as well as workflow orchestration technologies such as Temporal.

• Work with Salesforce specialists and engineering teams to incorporate Salesforce effectively into existing engineering workflows and systems.

• Partner with identity verification and RegTech vendors to implement technology solutions that respond to evolving regulatory requirements.

• Apply pragmatic engineering principles, prioritizing simplicity, maintainability, and effectiveness while avoiding unnecessary complexity.

• Design sustainable, future-proof products and services that can evolve alongside business needs and regulatory expectations.

• Contribute to engineering practices that maintain compliance, strengthen onboarding capabilities, and support high automated approval rates without compromising regulatory standards.

• Participate in collaborative engineering practices, technical discussions, and continuous improvements across the team.

Requirements:

• Strong professional experience as a backend software engineer, with deep proficiency in Java, Kotlin, or similar JVM-based programming languages.

• Proven experience designing, developing, and operating microservices in distributed systems environments.

• Solid understanding of relational databases, particularly PostgreSQL, and event-driven architectures using technologies such as Kafka, AWS SQS, and SNS.

• Experience working with cloud platforms such as AWS, Google Cloud Platform (GCP), or Microsoft Azure.

• Practical experience with containerization and orchestration technologies, including Docker and Kubernetes.

• Familiarity with infrastructure-as-code concepts and modern software delivery practices, including CI/CD pipelines.

• Experience with observability and reliability practices, including logging, metrics, distributed tracing, and performance optimization.

• Comfortable using Jira, Confluence, Git-based workflows, and collaborative software development processes.

• Strong communication skills, with the ability to explain technical concepts clearly to both technical and non-technical stakeholders.

• A pragmatic and thoughtful approach to problem-solving, with the ability to assess trade-offs and choose effective solutions without over-engineering.

• Experience in fintech, payments, or banking infrastructure is an advantage, particularly in fiat payment processing, clearing, or settlement.

• Exposure to payment schemes, banking APIs, or multi-rail payment routing and orchestration is beneficial.

• Familiarity with stablecoin or cryptocurrency infrastructure and fiat-to-crypto integration is a plus.

• Understanding of domain-driven design and hexagonal architecture patterns is desirable.

• Experience with reconciliation systems, idempotency patterns, and eventual consistency in financial workflows is an advantage.

• Previous experience in high-growth or rapidly scaling technology environments is beneficial.

• Experience contributing to engineering strategy, recruitment, or organizational scaling initiatives is a plus.

Benefits:

• Competitive salary based on experience and relevant certifications.

• Flexible working hours and a hybrid/remote working approach.

• Flexible holiday policy.

• Opportunities to travel to offices around the world.

• A collaborative culture built around passionate, growth-oriented professionals.

• An open and creative environment where employees can contribute to technical direction, team culture, and future opportunities.

• Opportunities to work on large-scale financial infrastructure and modern identity and compliance technologies.