Senior Software Engineer

NMI is excited to add a Senior Software Engineer to our growing team in South Africa. This role sits within the Protocols team—responsible for building and maintaining mission-critical services that connect to card payment acquirers and processors. These systems, written primarily in C#, must be scalable, secure, observable, and highly available, ensuring seamless transaction processing for our global customer base.

The Protocols team is part of NMI's Payments Gateway group, which focuses on developing and maintaining world-class payment solutions, including PIN pad and card reader integration and processor/acquirer connectivity. As a Senior Engineer, you'll have a direct impact on how payments flow through the NMI platform, playing a key role in evolving our architecture and building scalable solutions. This role is ideal for engineers who thrive in dynamic environments, lead by example, and are eager to make critical systems more reliable, scalable, and maintainable.

Key Responsibilities

• Contribute to the architecture of highly observable and fault-tolerant systems.
• Lead technical discussions, participate in code reviews, and drive best practices in maintainability and performance.
• Actively mentor and support the growth of junior team members.
• Collaborate with cross-functional teams, including Product and QA, to ensure high-quality delivery.
• Contribute to the evolution of our CI/CD pipelines and observability tooling.
• Participate in the out-of-hours on-call rota to respond to incidents impacting payment flow.

Skills & Experience

• Bachelor's degree in Computer Science, Information Technology, or equivalent experience.
• Minimum of 5 years of experience developing complex software applications in a commercial environment.
• Advanced proficiency in C# (preferred) or Java, with strong understanding of object-oriented design principles.
• Deep understanding of the full software development lifecycle (SDLC) and agile methodologies.
• Experience with relational databases (e.g., MySQL, SQL Server, Oracle).
• Strong knowledge of security best practices (e.g. OWASP, PCI, SOC2, HIPAA).
• Proficiency with Google Cloud Platform (GCP), Amazon Web Services (AWS), or similar cloud environments.
• Demonstrated experience applying modern software development practices in a collaborative, agile environment.
• Excellent communication skills, with a proven ability to mentor others and contribute to a strong team culture.
• Experience with logging systems (such as Logz.io) and optimizing logs preferred.
• Experience with containerization (e.g. Kubernetes, Docker, etc.) preferred.
• Experience with monitoring and alerting systems (e.g. DataDog, NewRelic, etc.) preferred.

Come join a growing fintech company and grow your tech career!

• Annual salary as of R550,000 - R675,000 + bonus
• 15 days holiday + 12 public holidays each year (+ 1 day after each year of service with up to a max. of 20 days)
• Family friendly policies (Enhanced Maternity and Paternity Pay).
• A chance to develop with an allocated company training budget
• A strong commitment to employee wellbeing including mental health first aiders and weekly yoga sessions.
• Employee referral scheme with generous financial reward
• Bonusly colleague reward scheme
• Fun culture events (company volunteering days, seasonal parties)
• Medical Aid and Gap Cover

About us
We enable our partners with choice, and challenge the one-size-fits-all approach to payment. You’ve probably used NMI in the last 24 hours without even realizing it. We’re the platform that powers success for innovative tech created by SMBs, entrepreneurs and fintech startups. 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 democratize the latest payments technology so that everyone can realize the benefits of easy payments across the full spectrum of commerce. We’re all about enabling more payments in more ways and more places.

We believe that having a diverse group of employees strengthens both our work and our workplace. We’re focused on making NMI more diverse and welcoming with initiatives like having a dedicated Diversity, Equity & Inclusion action group, diversity goals for hiring, anonymized resume screening, affinity groups such as our Women's network and LGBTQ+ Network, open forums for discussions on diversity and social justice, and measuring inclusion and belonging as part of our regular employee engagement surveys.

Do you feel like you have a slightly out of the ordinary career path or history? We are open to all walks of life and very willing to hear your story. Please don’t feel like this should be a barrier to securing a great career at NMI! We appreciate success can come in all shapes and sizes. Fill in the ‘Additional Info’ box on our application to tell us more about your path.

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.