Staff Engineer - Trust & Vault

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Staff Engineer - Trust & Vault based in Spain.

Join a senior engineering role focused on protecting sensitive payment data and improving transaction performance at global scale. You’ll lead the architecture of foundational systems spanning card vaulting, tokenization, authentication, and payment optimization. Your work will support secure, resilient payment experiences where reliability, compliance, and performance are non-negotiable. You’ll design bank-grade distributed systems while helping a highly technical team adopt strong engineering practices and full production ownership. The role is deeply hands-on, combining architecture, implementation, technical leadership, and mentorship. You’ll work across Product and senior engineering functions in an international, remote-first environment where your decisions can directly influence the reliability and efficiency of payment infrastructure.

Accountabilities

• Own the technical architecture and long-term direction of the Trust & Vault domain, covering card vaulting, tokenization, authentication, payment optimization, account updater capabilities, and portfolio migration.
• Design and evolve secure systems for tokenizing, storing, and retrieving sensitive card data within PCI-compliant boundaries.
• Architect and develop authentication capabilities such as 3DS/SCA and network tokenization to strengthen transaction security while minimizing customer friction.
• Build payment optimization capabilities designed to improve authorization and acceptance rates through network tokens, account updater services, and intelligent use of vaulted payment credentials.
• Design and maintain resilient, highly available, low-latency systems suitable for a zero-tolerance-for-failure production environment.
• Establish clear, versioned APIs and event-driven architectures that support scalable and maintainable platform services.
• Champion a full-service ownership culture in which engineering teams design, deploy, monitor, and operate their own microservices in production.
• Ensure systems are designed for multi-tenancy, elastic scaling, automated observability, and strong operational resilience.
• Apply AI-assisted engineering tools across architecture, implementation, testing, and code review while helping establish effective practices for their adoption.
• Partner with Product, senior engineering leaders, and cross-functional technical teams to solve complex problems and remove organizational or technical silos.
• Mentor engineers, influence engineering standards, and raise the technical quality of the wider engineering organization.
• Drive technical initiatives from architecture through production, balancing feature velocity with security, reliability, compliance, and maintainability.

Requirements

• Extensive software engineering experience with deep expertise in Go and/or Kotlin, supported by strong understanding of broader software engineering and full-stack principles.
• Proven track record architecting robust, scalable, and maintainable distributed systems, including event-driven platforms, APIs, and cloud-native or serverless architectures.
• Strong knowledge of software architecture patterns, engineering best practices, and designing systems for high availability and operational resilience.
• Experience building foundational platform capabilities or complex distributed systems, ideally involving payment tokenization, card vaulting, authentication, or PCI-scoped infrastructure.
• Strong hands-on experience with AWS and cloud-native services such as RDS, ECS, EKS, S3, or comparable technologies.
• Excellent automated testing practices across unit, integration, and end-to-end testing within Agile, DevSecOps, and CI/CD environments.
• Proven technical leadership experience, including mentoring engineers, defining technical vision, delivering complex cross-team initiatives, and helping teams improve delivery performance.
• Strong understanding of DORA metrics and experience identifying and removing technical or organizational blockers.
• Demonstrated preference for clean, modular, maintainable architecture and the judgment to balance compliance and reliability requirements against delivery speed.
• Advanced written and spoken English proficiency.
• Expertise in PCI DSS, card vaulting, tokenization, network tokenization, 3DS/SCA, or account updater services is highly advantageous.
• Experience improving payment authorization and acceptance rates through authentication, tokenization, or payment credential lifecycle management is a strong plus.
• Previous experience in payments or fintech, particularly at global scale, is preferred.
• Knowledge of performance optimization and efficient algorithms for high-throughput, low-latency systems is beneficial.
• Familiarity with static analysis and code-quality tools such as SonarQube and mature CI/CD pipelines is advantageous.
• Experience introducing engineering practices, standards, or technical improvements across multiple teams is a plus.
• Open-source contributions or technical writing demonstrating technical leadership are beneficial.
• Spanish proficiency is considered an additional advantage.
• Strong ownership, analytical thinking, communication skills, and the ability to operate effectively in a high-responsibility environment.

Benefits

• Competitive compensation.
• Fully remote working environment with the flexibility to work from anywhere.
• One-time home office allowance.
• Work equipment provided.
• Stock options.
• Health plan available wherever you are.
• Flexible days off.
• Language, professional, and personal development courses.
• Opportunity to work on critical payment infrastructure operating at global scale.
• Exposure to complex challenges across payment security, tokenization, authentication, distributed systems, and cloud infrastructure.
• International, remote-first working environment with experienced technical teams.
• Significant technical ownership and influence over foundational engineering systems.