Payment Processing Support Engineer

About Unlimit

Unlimit is the global fintech powerhouse behind the world's largest proprietary payments infrastructure.

Founded in 2009, Unlimit operates across 17 global offices with 700+ experts, seamlessly integrating 1,000+ payment methods into a single platform. From London to São Paulo, we empower businesses to scale across borders with a unified suite of financial tools — including payment processing, alternative payment methods, multicurrency business accounts, card issuing, banking-as-a-service, and crypto on- and off-ramps.

Our mission is to break down financial barriers and enable seamless money movement across borders. We give forward-thinking businesses the tools to accept, send, and manage payments effortlessly, wherever they operate.

As part of our dynamic growth, we are seeking a talented and proactive Support Engineer to join our team within the payment industry. The successful candidate will play a crucial role in maintaining the smooth operation of our SmartVista systems and providing expert technical support. If you have a solid background in payment processing, technical troubleshooting, we encourage you to apply.

The vacancy expects working from one of the offices: Limassol or Belgrade

• Maintenance of in-house systems of the in-house Card Processing platform (SmartVista)
• Demonstrate proficiency in troubleshooting and resolving issues across all SmartVista modules, conducting thorough root cause analyses, and implementing effective remedial actions
• Escalate cases to internal teams in a timely manner, adhering to established benchmarks and requirements
• Develop and implement fixes or workarounds to ensure business and processing continuity, while carefully evaluating the implications and risks of each alternative solution
• Online monitoring and performance approval rate, analysis of system events - logs, etc
• Lead the resolution of client problems alongside team members
• Customization of the business rules of the system in accordance with the requirements of internal customers
• Installation of authorization system releases
• Participation in the preparation of technical requirements for updating the system
• Interaction with external vendors and partners in the technical part
• Automation of routine: file sharing, reporting for regulators, etc
• Setting up emulators of payment systems

• 3+ years of experience supporting card processing systems (experience with BPC SmartVista is considered a significant advantage), including maintenance, troubleshooting, and performance monitoring.
• Strong understanding of the authorization and clearing processes in card payment systems.
• Knowledge of e-commerce payment systems and methods, including EMV 3-D Secure, recurring transactions, and other E-commerce-specific protocols.
• Advanced user of Linux, with hands-on experience in system operations, scripting, and troubleshooting.
• Proficient in PL/SQL, with the ability to write SQL scripts, including writing CRUD queries and medium-complexity stored procedures for data manipulation and system tasks.
• Skilled in at least one scripting programming language: Perl, Python, or Groovy, enabling automation and system integration.
• Experience in installing system updates, performing post-release monitoring, and managing the stability of live systems.
• Solid knowledge of encryption principles and PCI DSS security standards applicable to payment systems.
• Familiarity with the HTTP application layer protocol and web services integration (e.g., REST, SOAP).
• Knowledge of Java programming is an advantage
• Understanding of core card technologies, including EMV, PayWave, magnetic stripe cards, and Thales HSMs.

• Experience with various testing tools such as MAS, VTS, and others.
• Hands-on experience with clearing exchanges for major payment systems, including MasterCard File Express and Visa Edit Package.
• Solid understanding of the ISO 8583 protocol used for financial transaction messaging
• Experience working with Oracle WebLogic for application deployment and management.
• PL/SQL Developer, Bash, Python — for database work, automation, and scripting tasks.
• Tools such as Postman and SOAP UI for testing and validating APIs and web services
• Experience with automated tools for system testing and deployment (e.g., CI/CD pipelines, test automation frameworks).

• Attractive monthly salary paid in line with experience
• Vacation, sick, and paid holidays
• Flexible working hours
• Full-time: 5/2
• Modern workplace with all necessary equipment
• A team of top international professionals to learn from
• Multicultural working environment

Join Unlimit Team now

Unlimit is an equal opportunity employer. We believe passionately that employing a diverse workforce is central to our success. We make recruiting decisions based on your experience and skills. We welcome applications from all members of society irrespective of age, sex, disability, sexual orientation, race, religion or belief.