Senior Software Engineer

This London-based role sits at the core of Verifone's payments and checkout platform, where backend engineering directly impacts secure, high-volume transactions used globally. You'll design and operate scalable, production-critical systems that must perform reliably under real-world load, evolving payment methods, and strict security requirements., We are seeking a London-based Senior Software Engineer (Node.js / TypeScript) to build and operate backend services supporting payment, checkout, and transactional workflows. You will collaborate closely with Product, Frontend, Platform, and Infrastructure teams to deliver secure, scalable APIs in high-throughput environments.

Do you have experience in TypeScript?, * Backend frameworks such as Hapi.js, or alternatives including Express, Fastify, or NestJS

• Validation using Joi
• Authentication and authorization using JWT and OAuth2

Architecture & Design

• Strong grounding in Clean Architecture and Domain-Driven Design (DDD)
• Dependency Injection (e.g., InversifyJS)
• Repository and modular design patterns
• Experience building maintainable, testable backend systems

APIs & Data

• Design and operation of RESTful APIs
• API versioning and request validation
• Advanced filtering using RSQL or equivalent
• Experience with MongoDB (modeling, indexing, performance tuning)
• Experience with Redis for caching or messaging
• Database migrations and schema evolution

Cloud & Infrastructure

• Hands-on experience with AWS services such as EC2, S3, Secrets Manager, and CloudWatch
• Docker and Docker Compose
• Strong discipline with CI/CD pipelines and Git workflows

Testing & Quality

• Automated testing using Jest or Mocha/Chai/Sinon
• End-to-end testing with Cypress (optional)
• Strong focus on code quality, reliability, and maintainability

Preferred Skills and Experience

Payments & Security

• Experience integrating payment providers such as Stripe, PayPal, or Klarna
• Knowledge of authorization, capture, and refund flows
• Experience with 3D Secure
• Awareness of PCI-DSS requirements and security best practices
• Understanding of checkout and transactional domain flows

Production Engineering

• Performance optimization and debugging in production systems
• Exposure to monitoring or APM tools (e.g., AppDynamics or similar)
• Experience operating high-availability or fault-tolerant systems
• Familiarity with fraud-related considerations

Frontend & Platform Exposure

• Experience working alongside frontend frameworks such as Angular or React
• Familiarity with RxJS and state management (NgRx or Redux)
• Server-side rendering with Pug templates
• HTML/CSS with SASS or PostCSS
• Iframe-based widget embedding, * Fintech, payments, or e-commerce domain experience
• Messaging systems such as Kafka, RabbitMQ, or Redis Pub/Sub
• Internationalization (i18n) systems
• Puppeteer for PDF or receipt generation