Certifications Software Engineer

NMI is a leading provider of payment gateway solutions, specializing in card-present solutions and payment processing. Our innovative technologies empower businesses to securely accept payments and optimize transaction processes. With a focus on reliability, security, and innovation, we continuously push the boundaries of what's possible in the payments industry.

We are seeking an experienced Software Engineer to join our Payments Processing group. This group focuses on developing and maintaining world-class payment solutions, including PIN pad and card reader integration and processor/acquirer connectivity.

The Ideal Candidate:

We're looking for a software engineer with strong development skills and a passion for building robust tooling and automation. In this role, you’ll take technical ownership of EMV Level 3 certification projects, working closely with payment processors, financial institutions, and internal engineering teams. You’ll design and develop custom tools, execute and automate certification tests, and help ensure that our payment systems meet the highest standards of compliance and reliability.

As part of the Payment Gateway group, you’ll also have opportunities to contribute to broader platform initiatives, providing a strong foundation for technical and career growth.

Key Responsibilities:

• Design, develop, and maintain internal tools used in EMV Level 3 certification and payment gateway integrations.
• Build and execute automated test suites for processor certifications and regression testing.
• Write clean, maintainable, and well-documented code to support internal certification and validation workflows.
• Take technical ownership of certification projects, managing deliverables and timelines.
• Analyze certification test cases and ensure correct implementation based on requirements from financial institutions and networks.
• Work closely with other engineers and external certifying bodies to identify and resolve integration issues.
• Maintain accurate and thorough technical documentation throughout the project lifecycle.
• Communicate progress and blockers clearly to stakeholders and technical leads.

Skills & Experience:

• Bachelor’s degree in Computer Science, Software Engineering, or a related field — or equivalent industry experience.
• 2+ years of experience in software development.
• Proficiency in C# (preferred) or Java, with a solid understanding of object-oriented principles and design patterns.
• Experience with relational databases such as MySQL, SQL Server, or Oracle.
• Familiarity with building developer tools, test automation frameworks, or system integration software.
• Understanding of secure coding best practices and compliance frameworks (e.g., PCI DSS, OWASP Top Ten).
• Comfortable navigating complex technical systems and debugging issues across multiple layers of a stack.
• Strong communication and collaboration skills — able to work cross-functionally with developers, analysts, and external partners.
• Highly organized, self-directed, and detail-oriented.

As well as being a part of something exciting everyday, you will also receive the following benefits:

• Annual bonus scheme dependent on individual and company performance 
• Annual salary of £32,000 - £40,000
• 25 days holiday each year (+ bank holidays + 1 day after each year of service with up to a max. of 30 days)
• Workplace pension scheme
• Private medical insurance (upon 30 days of employment)
• 7 hours per day, 35 hours per week
• A remote first culture
• Great work-life balance with our Flexi-time policy
• Family Friendly policies (Enhanced Maternity and Paternity Pay and Shared Parental Leave).
• A chance to develop with an allocated company training budget
• Bike2Work Scheme
• Lifeworks, an Employee Assistance Programme which offers wellbeing, family and financial support services, such as assessments, resources and even 1:1 counselling sessions. It also offers interesting perks such as discounts on gyms, restaurants, high street retailers and cinema tickets
• A strong commitment to employee wellbeing including mental health first aiders
• Employee referral scheme with generous financial reward
• Bonusly colleague reward scheme

We’re looking for creative and passionate people who share our vision of making payments easy. If that sounds like you and you meet the requirements above, then please click on 'Apply for this job'!

We are an Equal Opportunities employer and will provide reasonable support throughout the recruitment process to applicants who have a disability. Please let us know in advance so that any support, aids or adaptations can be put in place to assist you.

Please be aware that all offers of employment are made subject to receipt of satisfactory background and financial checks.

About us

NMI enables our partners with choice, and challenges the one-size-fits-all approach to payments. You've probably used NMI in the last 24 hours without even realising it. We’re the platform that powers success for innovative tech created by SMBs, entrepreneurs and fintech start-ups. We’re creative problem solvers who help visionaries smash through boundaries and think beyond what’s possible so they can think about what’s next. But we’re not just built for the tech savvy. We democratise the latest payments technology so that everyone can realise the benefits of easy payments across the full spectrum of commerce. We’re all about enabling more payments in more ways and more places.

Please note that in compliance with the data protection regulations within your jurisdiction, any personal information submitted with your job application may be collected and used by NMI for the purpose of recruitment and employment-related activities. By submitting your application, you acknowledge and provide explicit consent to the processing of your personal information as described in our privacy policy found on our website. For more information on how we process your information, please read our privacy policy here: https://www.nmi.com/legal/privacy-policy/

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