Senior Software Engineer (Backend)

TL;DR

Senior Software Engineer (Backend): Developing and scaling identity, authentication, and authorization systems for a global travel and spend management platform with an accent on security-first engineering and system architecture. Focus on building robust identity layers, implementing SSO and enterprise provisioning, and optimizing developer-facing APIs.

Location: Hybrid in Barcelona. Must be based within commuting distance of the hubs.

Company

An intelligent platform for travel and spend management that automates bookings, expenses, and invoice processing for over 10,000 companies worldwide.

What you will do

• Own authentication and authorization systems for 10,000+ customers to ensure secure and seamless user experiences.
• Architect scalable identity systems supporting SSO, enterprise provisioning, and developer-facing integrations.
• Create design documents for auth system changes, balancing security rigor with developer experience.
• Set consistent identity handling patterns across the organization and collaborate with architects on cross-squad initiatives.
• Mentor team members, provide thoughtful code reviews, and raise the bar for security-first engineering.

Requirements

• Strong backend expertise in API design, token lifecycle management, and complex data models.
• Experience architecting scalable and evolvable identity systems with a focus on performance and security boundaries.
• Proficiency in operational security, including secrets hygiene, dependency risk, and threat modelling.
• Experience with CI/CD, testing strategies, and observability (SLOs, incident response).
• Must be based within commuting distance of the Barcelona hub.
• English: Official language of the office; proficiency required.

Nice to have

• Experience with or strong interest in modern AI-augmented workflows and agentic coding.

Culture & Benefits

• IRL-first work approach with team collaboration in-person 3 days a week.
• AI-embedded engineering workflow using AI-connected tools (Notion, Jira, GitHub, Slack) and agentic coding.
• Culture based on autonomy, pragmatism, ownership, and a "7-star experience" mindset.
• Diverse, international environment with colleagues from over 70 countries.
• Relocation assistance available for certain roles.