Senior Full-Stack Engineer (with Kotlin and AI agents experience)

About the Position

We're seeking a Senior Full-Stack Engineer with Kotlin and AI agents experience to join our European fintech team, building scalable backend and frontend systems.

About the Client

Our client is a fast-growing European fintech company in the business spend management space - corporate cards and related financial products - serving SME and mid-sized business customers across the EU and UK, in a regulated environment with GDPR compliance obligations. Engineering is organized into cross-functional squads, with platform/enabling teams providing shared tooling horizontally. The client already runs an AI-native engineering practice: tools like Claude Code and GitHub Copilot are used daily, supported by a growing library of shared, versioned Skills embedded in key repositories, enabling an end-to-end flow from ticket to implementation, testing, and PR in several codebases. AI tool/connector rollout follows an approved-list and pilot process. The client is AWS-first overall; for data platform and analytics workloads it also runs GCP, with BigQuery as the primary data warehouse. Day-to-day coordination is Slack-first, with Linear for ticket tracking, GitHub for code/PR review, and Notion as the knowledge base.

Responsibilities

• Deliver across the Kotlin backend and React/TypeScript frontend
• Move fluidly between stack layers to unblock delivery
• Apply AI-native delivery practices across the CDLC
• Multiply the output and quality of the squad you join, and share patterns/practice beyond your immediate team so adoption compounds across the organization
• Embed directly into a client squad as a hands-on Individual Contributor (not a coaching/managerial role)

Requirements

• Kotlin (backend) and React/TypeScript (frontend)
• AI-native delivery practices applied across the CDLC
• A clear leaning toward front-end or back-end depth, with the ability to move fluidly across stack layers
• Experience with AWS
• Agent & harness engineering fluency, with concrete evidence of building/operating this kind of tooling, not just using it

We Offer

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits

not applicable for freelancers