Senior Software Engineer - Connex

Our Purpose

Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential.

Title and Summary

Senior Software Engineer - Connex

Senior Software Development Engineer
Join a Leading Technology Company in Global Payments
Mastercard, a technology leader in global payments, connects consumers, financial institutions, merchants, governments, and businesses worldwide, enabling secure and convenient electronic transactions. Our innovative solutions power commerce across more than 210 countries and territories, while Vocalink technologies underpin the UK’s real-time payments, settlements, and ATM networks.

Role Overview
We are seeking a talented Senior Connex Software Development Engineer to join our dynamic, cross-functional team, working within the SAFe methodology. This is an exciting opportunity to contribute to the advancement of payment technologies.
Key Responsibilities

• Participate in team prioritisation discussions with Product and Business stakeholders. Estimate and take ownership of delivery tasks—including design, development, testing, deployment, configuration, and documentation—to meet business requirements.
• Automate the build, operation, and running aspects of software development and testing.
• Drive code, design, and process trade-off discussions within the team as needed.
• Report on status and manage risks within the primary application or service.
• Drive integration of services with a focus on the customer journey and experience.
• Perform demonstrations and acceptance discussions when interacting with Product Owners. Understand operational and engineering experiences and actively work to improve experience and metrics within the area of ownership.
• Develop a complete understanding of end-to-end technical architecture and dependency systems.
• Drive the adoption of technology standards and opinionated frameworks, as well as review coding, testing, and automation work of team members.
• Mentor and guide new and less experienced team members. Identify opportunities to improve overall processes and eliminate waste.
• Share and seek knowledge within the Guild or Programme to drive reuse of patterns, libraries, and practices, thereby enhancing productivity.
• Contribute to the test strategy across projects, including BDD-style functional, system integration, and non-functional testing such as volume, performance, resilience, and availability.
• Design innovative test scenarios to uncover potential issues that may not be immediately evident to others.
• Lead online real time transaction switching and ATM acquiring testing activities across multiple platforms.
• Set up, maintain, and execute test automation frameworks across various application platforms.
• Identify opportunities for test automation, prioritising automation efforts based on risk assessment throughout the delivery lifecycle.
• Ensure traceability from business requirements to acceptance criteria is established and demonstrable from the inception of the project.
• Drive innovation in automation across all application tiers, including UI, APIs, CLIs, Connex, HP NonStop, and database layers.
• Investigate and resolve technical issues reported by the customer support team.
• Bring experience in building comprehensive test scenarios and acceptance tests, collaborating within an iterative deployment environment.

Ideal Candidate Profile
• Highly experienced in Connex on HP NonStop development background.
• Understanding of financial industry hardware such as ATM’s, HSM’s HP Nonstop and related standards and security requirements including PCI and OWASP.
• Excellent understanding of online transaction processing, including knowledge of ATM transaction processing.
• Experience of TCP/IP and communication protocols.
• Strong knowledge of TAL, COBOL, SCOBOL and TACL
• Understanding of EMV and chip and PIN technology
• Knowledge of HP Non-Stop protocols, security and utilities
• Strong understanding of financial industry protocols including ISO8583, ISO20022, LIS5, VISA, MasterCard or ATM message protocols.
• Knowledge of some of GoldenGate, Electronic File Transfers, Java, UNIX, Spring, Hibernate, XML,
• Proven development experiences a solid background as a developer across various platforms.
• Proven technical testing experience within Agile environments, particularly with BDD methodologies.
• Hands-on automation testing expertise using open-source technologies such as Selenium, Cucumber, Gherkin, Spring, etc.
• Be comfortable with regular demonstrations to stakeholders and comfortable with pair programming.
• Exceptional communication skills, with the ability to collaborate effectively within a multidisciplinary team.
• Excellent time management and organisational abilities.
• Strong problem-solving skills and a proactive attitude.
• Genuine passion for testing, development, and technology design across diverse full stack platforms.
• Demonstrated experience in both functional and non-functional automated testing.
This role is perfect for individuals who thrive on success, possess a passion for continuous learning, and aspire to make a genuine difference in the world of payments technology. If you are enthusiastic about innovation, testing, and development, and are committed to upgrading your skills in line with evolving technologies, we would love to hear from you.

Corporate Security Responsibility

All activities involving access to Mastercard assets, information, and networks comes with an inherent risk to the organization and, therefore, it is expected that every person working for, or on behalf of, Mastercard is responsible for information security and must:

• Abide by Mastercard’s security policies and practices;

• Ensure the confidentiality and integrity of the information being accessed;

• Report any suspected information security violation or breach, and

• Complete all periodic mandatory security trainings in accordance with Mastercard’s guidelines.