Principal Software Engineer (Payments)

An international cross-border payments company are looking for a Principal Software Engineer to help build and scale their payment platform. You’ll work across the full stack - frontend, backend, cloud infrastructure, and data - designing reliable systems that power real financial transactions.

You'll lead their latest platform, provide technical expertise at both the architectural and hands-on development levels, and mentor junior team members.

What You’ll Do:

  • Design and build scalable payment applications and APIs
  • Develop modern frontend interfaces and backend services
  • Integrate with payment providers and financial systems
  • Optimise database performance and system reliability
  • Contribute to architecture decisions and technical strategy
  • Support CI/CD pipelines and cloud infrastructure
  • Mentor developers and promote engineering best practices

Tech Stack:

  • Frontend: TypeScript, JavaScript, (React/Angular), HTML5, CSS3
  • Backend: Python
  • REST APIs
  • Data: MySQL, PostgreSQL, Redis
  • Cloud & DevOps: AWS, Docker, CI/CD, Kubernetes (nice to have)
  • Architecture: API design, OAuth/JWT authentication, queues, webhooks, payment integrations
  • Previous experience in Financial Services

What We’re Looking For:

  • Strong system design and API architecture skills
  • Experience building high-performance, scalable applications
  • Comfortable working across frontend, backend, and cloud environments

For more details, apply now!

Job Details

Company
X4 Technology
Location
London Area, United Kingdom
Posted