Senior Software Engineer (Fintech)

TL;DR

Senior Software Engineer (Fintech): Developing and maintaining secure payment gateway solutions and SDKs with an accent on C#/.NET backend services and mobile integration. Focus on designing scalable architectures, ensuring PCI/OWASP compliance, and mentoring engineering teams to maintain high standards of reliability and performance.

Location: Must be based in the UK (Remote)

Salary: £48,000–£58,000 GBP

Company

A leading provider of payment gateway solutions empowering businesses to securely accept payments through innovative, reliable, and scalable technology.

What you will do

• Design and maintain secure, scalable SDKs and backend services for payment device integrations.
• Lead architectural discussions across backend and mobile platforms.
• Write and review maintainable, efficient code while ensuring adherence to security standards like PCI and OWASP.
• Collaborate with Product, QA, and Operations teams to deliver high-quality features.
• Mentor junior and mid-level engineers to foster technical growth.
• Participate in CI/CD evolution and contribute to deployment automation.

Requirements

• Must be based in the UK
• Minimum 5 years of commercial software development experience.
• Advanced proficiency in C# or Java with strong object-oriented design skills.
• Deep understanding of SDLC, agile methodologies, and design patterns.
• Experience with relational databases and performance optimization.
• Strong knowledge of networking concepts (sockets, HTTPS, SSL) and security best practices.

Nice to have

• Experience with mobile SDK development (Android/Java/Kotlin or iOS/Objective-C/Swift).
• Knowledge of SOC2 and HIPAA compliance requirements.

Culture & Benefits

• Remote-first culture with flexible working hours.
• 25 days holiday plus bank holidays, increasing with service.
• Private medical insurance and workplace pension scheme.
• Annual performance-based bonus scheme.
• Training budget for professional development and Employee Assistance Programme.
• Family-friendly policies including enhanced maternity/paternity pay.