Senior Engineer (MERN)

Job description

TransFi’s purpose is to power the world’s payments, helping businesses and individuals access better ways to move money. Combining industry-leading coverage of currencies and payment methods, we deliver compliant payouts, collections, and ramp services across Asia, Europe, LatAm, Africa, and North America. In our pursuit to advance economic prosperity through borderless finance, TransFi’s enterprise-grade, developer-friendly platform is quietly transforming global payments—making international money movement faster, less expensive, and more reliable than ever.

Trans-Fi is remote first; we believe the best talent comes from all over the world. Our team is distributed over multiple countries and continents. We are building for the long term and look for strong owners, builders and big thinkers. Join us if you want to build the future of global finance

What You’ll Do

Design & Implement Payment Systems

Architect and build scalable, reliable payment flows (checkout, refunds,subscriptions).

Integrate with PSPs and maintain PCI-compliant practices.

Build & Maintain Front-End

Develop performant, accessible React components in a Vite / CRA environment

Ensure great UX across devices and handle complex client-side state / data concerns

Drive Security Best Practices

Identify, remediate, and prevent security ulnerabilities (OWASP Top 10, JWT management, CORS, CSP)

Conduct regular threat modeling and code reviews with a security lens

Ensure Quality Through Testing

Write and maintain unit and integration tests (Jest, Vitest, React Testing

Library)

Collaborate on E2E test suites (Playwright, Cypress) to validate critical flows

Own Your Deliverables

Take full lifecycle ownership—from scoping and estimation through deployment and monitoring

Proactively identify and solve production issues, implement observability (logs, metrics, alerts)

Document Thoroughly

Produce clear API specs, README updates, onboarding guides, and architectural diagrams

Keep internal Wikis and Confluence pages up to date

What We’re Looking For

Experience :

5+ years in full-stack JavaScript development (MERN : MongoDB, Express,

React, Next.js, Node.js)

Hands-on with payment gateways and transaction lifecycle design

Technical Skills :

Strong proficiency in React (hooks, context, performance optimization)

Deep understanding of Node.js back-end patterns (RESTful APIs, middleware, error handling)

Solid database design and querying expertise with MongoDB (aggregation,

indexing, replication)

Quality & Security :

Proven track record writing comprehensive unit tests (Jest / Vitest) and integration tests

Familiarity with security best practices : authentication, authorization, encryption, OWASP mitigations

Soft Skills :

Exceptional ownership mentality—you drive features from concept to production

Excellent written communication and documentation skills

Collaborative mindset : you enjoy pairing, code reviews, and knowledge sharing

Nice-to-Haves

Experience with TypeScript across front-end and back-end

Familiarity with containerization (Docker) and cloud deployments (AWS / GCP)

Background in microservices or event-driven architectures

Exposure to CI / CD pipelines and infrastructure as code

Why Join Us?

Impact : Your work will power critical payment flows for thousands of users every day.

Growth : Strong mentorship, bi-weekly tech talks, and training stipends.

Flexibility : Work remotely.

Culture : A supportive team that values autonomy, learning, and continuous

improvement.