Senior Full Stack Engineer (KLI-90)

Responsibilities

• Build and maintain complex multi-step application and onboarding journeys, including validation, document uploads, resumable states, and KYC flows.

• Develop customer, dealer, and operations portals using TypeScript, React, and Next.js.

• Build backend use cases, APIs, database queries, and integrations — this is not a UI-only role.

• Integrate with CRM, workflow engines, compliance services, credit systems, and other external platforms.

• Ensure accurate data mapping and reliable end-to-end application flows.

• Develop and maintain E2E tests for critical customer journeys.

• Collaborate with engineering teams in Berlin and product/operations teams in Switzerland.

• Contribute to specification-driven and AI-assisted development.

Requirements

• 6+ years of full-stack engineering experience with TypeScript.

• Strong recent production experience with React and Next.js App Router.

• Mandatory: Experience working with fintech or regulated financial products.

• Proven experience owning complex onboarding or application flows.

• Strong backend capabilities, including APIs, databases, business logic, and system integrations.

• Experience with state management and data-fetching tools such as Zustand or TanStack Query.

• Experience with React Hook Form/Formik and Zod is preferred.

• Experience with Playwright or Cypress for E2E testing.

• Experience building multi-language/internationalised applications.

• Professional English communication skills.

• Experience with KYC, AML, credit/identity verification, or workflow/BPM integration is a plus.