NMI Bristol, England, United Kingdom Full-time 2024-03-07

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 a highly skilled and experienced P3 Senior Software Engineer to join our dynamic team at NMI. Reporting to the Engineering Manager for Device Platform Team, you will play a key role in leading technical initiatives within the team. As a senior technical person within our team, you will support major projects, mentor junior engineers, and offer technical guidance to ensure the delivery of high-quality software solutions.

Key Responsibilities

  • Lead the design and implementation of backend services, primarily using C# and PHP, ensuring the development of scalable, secure, and efficient payment processing solutions.
  • Develop and maintain comprehensive unit, application-level, and system tests to ensure the reliability and robustness of payment gateways and related systems.
  • Regularly update and enhance the payment gateway system to improve performance, security, and user experience.
  • Thoroughly document code, business logic, and system architecture to ensure clarity and maintainability of the software development process.
  • Build and maintain secure APIs to facilitate seamless, secure data exchange and integration with other systems and services.
  • Mentor junior engineers and team members, promoting best practices in software engineering and fostering a culture of continuous learning and professional growth.
  • Participate in Agile development processes, contributing to the continuous improvement of team workflows and project management practices.
  • Ensure that all development activities comply with relevant security standards and protocols, particularly those related to financial transactions and data protection.



  • Bachelor of Arts/Science in Computer science or other experience commensurate.
  • Minimum of 4 years of experience developing complex applications in a commercial environment.
  • Expert level in C# preferred. Experience in another object-oriented language like Java and PHP will also be considered. 
  • Working knowledge of Linux for developing and deploying applications.
  • Demonstrated track record of delivering technical projects on time and within budget.
  • Commitment to continuous learning and professional development.
  • Must be able to work collaboratively with others.
  • Must be an independent and critical thinker.


  • Familiarity with Agile methodologies and a solid understanding of DevOps practices.
  • Proficiency in managing and deploying solutions in on-premise, Google Cloud Platform (GCP), and Amazon Web Services (AWS) cloud environments.
  • Skilled in designing and implementing optimized queries for relational databases.
  • Proven track record in the development and upkeep of applications that are highly available


Why Join NMI:

At NMI, we offer a dynamic and collaborative work environment where you will have the opportunity to make a meaningful impact in the payments industry. As a member of our team, you will be empowered to innovate, grow, and succeed in your career. We value diversity, creativity, and teamwork, and we are committed to fostering an inclusive culture where everyone can thrive.

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

  • Competitive salary of £45,000-£61,000 max per annum (dependant on experience)
  • Annual bonus scheme dependent on individual and company performance 
  • 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 flexible hybrid working arrangement
  • 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
  • Telus Health, 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

How to Apply:

If you are a passionate and driven software engineer with a deep understanding of payments and a desire to lead technical initiatives, we want to hear from you! Please submit your resume and cover letter outlining your relevant experience and qualifications.

Join us at NMI and help shape the future of payments!

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.