Sr. Fullstack Engineer

About Tereina

Tereina is on a mission to revolutionize B2B payments. We are a well-funded, early-stage startup building cutting-edge solutions that transform how businesses move money. Our platform handles cross-border payment processing, counterparty management, bank account administration, and compliance workflows for eterprise customers worldwide.

We are building a modern portal application using a service-oriented architecture with Spring Boot microservices, a Spring Boot BFF (Backend for Frontend), and a custom frontend built with SAP UI5 Web Components, React and TypeScript. We are currently evolving our UX with a clean, data-rich design language focused on advanced search, tabular data views, and dashboard analytics.
About the Role

As a Senior Fullstack Engineer, you will be a key technical leader responsible for shaping the user experience of the Tereina Portal. You will own the frontend architecture, drive the implementation of our new design system, and work across the full stack to ensure our UX vision is realized with production-quality code. You will partner closely with product, design, and backend engineers to deliver enterprise-grade interfaces for payment operations, counterparty management, and compliance with workflows.

This role demands deep expertise in modern frontend technologies, a strong eye for design quality, and the ability to influence architecture decisions across the portal and its supporting BFF layer. You will mentor other engineers on UX best practices and help define our standards for accessibility, performance, and component reusability.
Key Responsibilities
Framework Development

These are the responsibilities focused on building the underlying systems, architecture, and shared infrastructure:

- Frontend Architecture: Own and evolve the frontend architecture of the Tereina Portal, including the component library, state management patterns, and data-fetching layer built on our existing frontend infrastructure.

- Design System Implementation: Lead the implementation of our evolving design system, translating UX designs into reusable, accessible components using SAP UI5 Web Components and TypeScript. Establish patterns for dashboards, data tables, search interfaces, and detail views.

- BFF Collaboration: Work closely with the BFF layer (Spring Boot) to shape API contracts, optimize data-fetching patterns, and ensure the portal proxy controllers deliver exactly what the frontend needs. Influence the design of search proxy endpoints and OpenAPI specifications.

- Performance & Accessibility: Champion frontend performance optimization (lazy loading, caching strategies, efficient re-renders) and WCAG accessibility standards across all portal views.

Rollout & Adoption

These are the responsibilities focused on shipping features, driving usage, and working across teams:

- Search & Data Views: Architect the frontend implementation of our new standardized search framework, integrating table-based server-side pagination, sorting, and filtering via our REST filter contracts. Implement column configuration, saved searches, and spreadsheet exports.

- Dashboard & Analytics UX: Build rich, interactive dashboard experiences including payment summaries, held-payment alerts, trend charts, and failure-analysis views.

- Implement data visualizations that surface actionable insights for enterprise payment operations.

- Cross-Functional Leadership: Partner with Product, Design, and Platform teams to translate business requirements into UX solutions. Drive UX technical decisions and advocate for user experience quality in architectural discussions.

- Mentorship: Mentor mid-level and junior engineers on frontend best practices, code quality, component design, and UX engineering principles. Lead code reviews, establish coding standards, and help shape the engineering culture as the team grows.

Required Qualifications

- 7+ years of software engineering experience with a strong focus on frontend dev