Processing Development 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 Processing Development Engineer to join our team within the payment industry. The successful candidate will play a crucial role in maintaining the smooth operation of our Processing Platform (SmartVista) and providing expert technical development of our card products. 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: Belgrade or Limassol.

Responsibilities:

• Technical implementation of the company's new projects in terms of card processing
• Selection, planning, and coordination of architectural solutions, technology stack
• Setting up and installing authorization system releases
• Passing certification tests, audits of payment networks
• Study of specifications, norms, and rules of payment networks
• Lead the resolution of client problems alongside team members
• Actively participate in customer go-live activities and pilot phases
• Preparation of technical requirements for system upgrades
• Setting up emulators of payment systems

Requirements:

• 3+ years of experience in card processing systems, with proven expertise across the full payment lifecycle — including authorization, clearing, and settlement
• Strong background in card processing platforms (experience with BPC SmartVista is considered a significant advantage)
• In-depth understanding of payment industry standards, including ISO8583, SOAP, and others and certification processes with Card Schemes (Visa, Mastercard, etc.)
• Technical proficiency with tools and scripting languages such as Bash, SQL/PLSQL, Postman, and Python, with a practical, hands-on approach to troubleshooting and integration
• Proficient in using banking applications, Oracle DB, WebLogic, and Bash scripting
• Experienced with Visa Edit Package, MasterCard File Express, and emulators such as MasterCard, MAX, and Visa test tools
• Skilled in analyzing documentation and technical specifications from Card Schemes (Visa, Mastercard, etc.)
• Solid experience in certifying card products with major Card Schemes, ensuring compliance with regulatory and technical requirements
• Familiar with e-commerce payment technologies, including EMV 3-D Secure, recurring payments, Apple Pay, Google Pay, VTS, AVS, and related methods
• Experience in planning and deploying system updates, ensuring minimal downtime and operational stability
• Knowledge of application-layer protocols, particularly HTTP, and a solid understanding of web service principles
• Familiar with a wide range of card technologies, including EMV, PayWave, magnetic stripe cards, Thales HSMs, and OBKM
• Demonstrates a high capacity for continuous learning, adaptability to evolving system requirements, and responsiveness to partner and regulatory changes
• Understanding of J2EE (WebLogic) and Oracle database administration

Will consider as a plus:

• Strong understanding of the regulatory framework and operational rules of major payment systems and European regulators, including PCI DSS, PSD2, ATNGE, Liability Shift, etc
• Skilled in maintaining technical documentation and producing structured, clear system documentation
• Experience in planning and reporting activities related to payment processing
• Background in budgeting for payment infrastructure and project needs
• Hands-on experience with international and local payment systems: JCB, Discover (DCI), American Express (AmEx)
• In-depth knowledge of clearing and settlement exchanges with card schemes, including MasterCard File Express, Edit Package, and related tools

We offer:

• 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.