Postilion Developer

We are looking for an experienced Postilion Developer to design, enhance, and support payment switching solutions across ATM, POS, and e-commerce channels. The ideal candidate is fluent in the subtle dialects of ISO 8583, transaction flows, and Postilion modules, and can translate complex payment logic into stable, secure, and scalable implementations. Key Responsibilities • Develop, configure, and maintain components within the Postilion suite (Office, Realtime, Config Server, PostCard, PostBridge, Postilion SDK). • Build and enhance ISO 8583-based transaction processing logic for acquiring, issuing, and routing. • Implement host interfaces, BIN tables, routing rules, interchange configurations, and settlement mappings. • Integrate with external systems such as Visa, Mastercard, hosts, CBS, ATM driving systems, POS acquirers etc. • Prepare technical documentation, deployment scripts, configuration guides, and operational procedures. • Work with QA and operations teams during testing, certification, and go-live activities.

Technical Skills Required • Hands-on experience with Postilion Realtime and Office modules. • Strong understanding of ISO 8583, EMV, key exchange, terminal parameters, host messages. • Good knowledge of card switching, acquiring, issuing, settlement cycles. • Experience in C#, .NET, SQL Server, and Postilion SDK (APIs, scripts, DLL extensions). • Familiarity with Postilion Base24 interfaces, POS/ATM protocols, and network routing is a plus. • Ability to read logs, trace packets, and analyze message life cycles. • Understanding of HSM, key management (DUKPT, ZMK/ZPK/ZAK), security concepts 1. Programming Languages  Hands-on coding experience with Java 8 and above  Good to have knowledge of C# (.NET) for custom interfaces and extensions  Strong understanding of Object-Oriented Programming (OOP) principles  Basic understanding of Python 2. Database & Querying  Proficient in SQL Server (queries, stored procedures, performance tuning)  Familiarity with Postilion Realtime and Postilion Office databases 3.

Postilion Realtime Framework  Working knowledge of the Postilion Realtime SDK  Well-versed with ISO 8583 standards  Familiar with VISA, Mastercard etc. scheme network 4. Testing & Documentation  Writing unit test cases for transaction flows  Preparing technical and functional documentation  Debugging and troubleshooting transaction issues