Job Openings Mid. Fullstack Engineer

About the job Mid. Fullstack Engineer

About the Role

As a Fullstack Engineer, you will play a central role in building user-facing features of the Tereina Portal. You will implement responsive, accessible interfaces for business onboarding, organization management, and payment and transaction workflows.

Working closely with the backend engineer and product team, you will translate designs into polished, production-ready React components. This role is ideal for an engineer who enjoys the intersection of design and engineering.

You will work with React, TypeScript, SAP UI5 Web Components, and Vite within a Spring Boot BFF architecture, with opportunities to introduce tools like TanStack Table as data views grow. You will have room to grow into a senior role as the team expands.

Key Responsibilities

  • UI Development: Build and maintain responsive, accessible user interfaces for the Tereina Portal using TypeScript, React, and SAP UI5 Web Components. Implement views for counterparty search, transaction monitoring, bank account management, business units, and user administration.
  • Search & Table Views: Implement data-rich table views using TanStack Table with server-side pagination, sorting, and column filtering. Build search interfaces that translate user interactions into our standardized filter contract, including multi-criteria filtering with AND/OR logic.
  • Dashboard Components: Develop dashboard widgets and data visualizations including payment summaries, KPI cards, trend charts, and alert tables (e.g., held payments, failed transactions). Work with the design team to bring mockups to production.
  • API Integration: Integrate frontend components with backend services via the portal BFF layer, using the existing infrastructure with CSRF protection. Work with OpenAPI-defined endpoints for search, CRUD operations, and data retrieval.
  • Design System Contribution: Contribute to the shared component library and design system. Build reusable components for forms, modals, status badges, filter controls, and data export (Excel/CSV introducing tools like SheetJS) that maintain consistency across the application.
  • Testing & Quality: Write comprehensive tests for UI components and integration flows. Participate in code reviews and maintain high code quality standards. Ensure cross-browser compatibility and responsive behavior.
  • Collaboration: Work closely with designers, product managers, and backend engineers in an agile environment. Participate in sprint planning, design reviews, and technical discussions to deliver features that meet both UX and business requirements.
  • Continuous Improvement: Stay current with front-end technologies and UX engineering practices. Propose improvements to our development workflow, tooling, and component patterns.

Required Qualifications

  • 3-5 years of software engineering experience with a focus on frontend development
  • Strong proficiency in TypeScript and modern JavaScript (ES6+)
  • Strong proficiency in React, including hooks, component lifecycle, and state management, with experience building responsive, component-based web applications
  • Hands-on experience with data tables and list views, including pagination, sorting, and filtering (TanStack Table or similar data table libraries experience is a plus)
  • Understanding of REST API integration and async data fetching patterns (fetch, axios, or similar)
  • Experience with AI agent frontends — streaming UI, conversation management, and integration with Spring AI, LangChain, or MCP backends
  • Familiarity with CSS Modules or CSS-in-JS, CSS custom properties, or design tokens for consistent theming
  • Experience with frontend testing frameworks (Jest, Vitest, Playwright, or Cypress)
  • Knowledge of web accessibility standards (WCAG) and semantic HTML
  • Comfortable working in agile teams with designers and backend engineers
  • Good communication skills and a collaborative mindset
  • Professional fluency in English (written and verbal) is required; all engineering collaboration, documentation, code reviews, and stakeholder communication are conducted in English

Preferred Qualifications

  • Experience with SAP UI5, SAP UI5 Web Components, or enterprise UI frameworks
  • Familiarity with headless UI libraries (TanStack Table, Headless UI)
  • Exposure to BFF (Backend for Frontend) patterns and Spring Boot applications
  • Background in fintech, payment processing, or B2B platforms
  • Experience with data visualization (D3, Chart.js, Recharts, or similar)
  • Familiarity with OAuth2/OIDC authentication flows and session-based security
  • Interest in design systems, component libraries, and UI/UX design principles
  • Experience with SheetJS or client-side data export functionality

Why Join Tereina?

  • Shape the Product: Own the UX of a platform that processes millions in B2B payments. Your work directly impacts how enterprise customers manage counterparties, execute payments, and maintain compliance.
  • Modern Stack: Work with a thoughtfully chosen technology stack that values simplicity and pragmatism over hype. We adopt new tools where they add real value.
  • Early-Stage Impact: Join a well-funded startup where your contributions shape both the product and the engineering culture from the ground up.
  • Full-Stack Exposure: Collaborate across the entire stack, from frontend components to BFF orchestration to backend service APIs.
  • AI-Forward Culture: We embrace AI as a tool for innovation and efficiency. We are looking for team members who are curious, adaptable, and excited to leverage AI in their work.
  • Team & Growth: Work with a collaborative, diverse team that values technical excellence, continuous learning, and work-life balance.