Fullstack Software Engineer

Tereina•San Francisco, CA

About The Position

Tereina is an early-stage, well-funded startup supported by SAP, building solutions to transform B2B payments. Its platform supports cross-border payment processing, counterparty management, bank account administration, and compliance workflows for enterprise customers. The company aims to enable payments to flow from initiation to beneficiary without manual intervention, with reliable software across every release and environment. As a Fullstack Software Engineer, you will design, build, and maintain web applications and the APIs that power them. You will develop intuitive, secure, responsive user interfaces and backend systems for large-scale financial transactions with real-time processing capabilities. You will work in an agile, cross-functional team alongside engineers, designers, and product managers, and report to the Engineering Manager. The role is suited to someone who enjoys working across the stack and building secure, compliant financial technology in an early-stage environment.

Requirements

At least 5 years of software engineering experience, including significant fullstack development focused on frontend applications and backend API development.
Strong proficiency in ReactJS and modern JavaScript/TypeScript.
Solid experience with backend frameworks such as Node.js, Java/Spring, or similar.
Hands-on experience with both SQL and NoSQL databases.
Understanding of data modeling and database optimization.
Hands-on experience with Jest, Cypress, Playwright, or other modern testing frameworks, with a focus on test-driven development.
Experience designing scalable web applications, microservices architecture, and API integration patterns.
Experience with Scrum/Agile methodologies, sprint planning, and collaborative development practices.
Ability to debug and optimize for performance, security, and reliability.
Excellent communication skills in a collaborative, fast-paced environment.

Nice To Haves

Background in fintech, banking APIs, payment processing, or commercial payment systems.
Experience with websockets and real-time data processing.
Exposure to enterprise-grade UI/UX standards in regulated industries.

Responsibilities

Build and maintain modern, responsive, secure web applications using ReactJS and TypeScript, with a focus on performance and accessibility.
Use React-based libraries to create enterprise-grade UI components that meet financial industry standards.
Design, build, and maintain RESTful APIs and GraphQL endpoints.
Design efficient data models and work with SQL and NoSQL databases for transactional and analytical workloads.
Implement websockets, message queues, and event-driven architectures for real-time payment processing and notifications.
Write comprehensive tests using Jest, Cypress, Playwright, or similar frameworks, and participate in code reviews.
Apply security practices including CSP implementation, secure coding, data encryption, and vulnerability assessment.
Improve performance, scalability, and observability through data compression, caching, CDN optimization, and monitoring.
Collaborate with Product, Design, and Platform teams to deliver features that meet customer, compliance, and reliability needs.
Participate in knowledge sharing and code reviews, and mentor junior developers as the team grows.