Fullstack Engineer - Mid Level - Actions Team

You'll join the Actions team in building the core infrastructure that powers our plugin platform. You'll create the UI components, integration layers, and security mechanisms that enable our customers to extend the platform with custom integrations while maintaining safety and flexibility across our 1,500+ customer base.

What you'll do

• Building a UI component library that generated apps can assemble from, turning components like payslip views and approval flows into maintained, reusable pieces instead of regenerated artifacts
• Creating the connection layer between generated apps and customer source systems—HR platforms, time-tracking and scheduling systems, and a long tail of vendors with thin or undocumented APIs
• Defining extension points (widgets, menus, sidebars) so plugins declare where they surface and what they connect to in a single, clean configuration
• Designing and implementing a cross-integration authentication solution that lets customers run multiple integrations without forcing employees to log in repeatedly
• Shipping plugins on the platform yourself, staying a consumer of what we build so we catch gaps early

What you'll need

• Strong knowledge of React and TypeScript for frontend work; Java/Kotlin or Go and TypeScript experience for backend services
• Real experience integrating third-party APIs, especially the challenging ones—inconsistent auth, partial documentation, legacy and on-prem systems
• Deep understanding of multi-tenancy security and data isolation; you care about scope checks and preventing cross-tenant leaks
• Good judgment about what to standardize and what to leave flexible—drawing that line in the right place is central to this role

Nice to have

• Comfortable with edge and serverless runtimes like Cloudflare Workers
• Experience building a plugin system, SDK, or developer platform
• Built a design system or component library that other teams depended on
• Real-world experience with OAuth and enterprise SSO

What they offer

• Competitive compensation including LTIP (unit-based Long Term Incentive Plan)
• Flexible working time models and hybrid work with €1,560 yearly flex work allowance
• 31 vacation days annually plus pro rata fully paid Fridays off during August
• Company pension scheme
• One volunteer day per year for supporting a social project