At CCV, Martin worked on the foundations of electronic payments in the Netherlands: security software for the first Pay-O-Maat PIN terminal, embedded terminal applications and transaction-processing systems.

His work included PIN calculation, PIN mailers, authorisation systems, communication front ends, simulators and security-key loading systems, as well as software for Chipknip, Chipper, fuel and loyalty terminals.

As Smart Concepts' second employee and first software engineer, Martin helped build its software development activities from the ground up. His role grew from hands-on development into technical leadership, architecture and quality management.

He developed payment, loyalty and card-processing solutions, including debit, credit and fuel applications, card personalisation, and terminal and host applications. This period also produced Visual Loyalty, reusable Visual FoxPro frameworks and middleware for terminal SDKs.

After the acquisition of Smart Concepts, Martin continued at ICP Companies, working on payment architecture, transaction processing, security and terminal integration. He developed authorisation and communication switches, online loyalty and prepaid platforms, and Terminal Management System functionality.

He also built C# frameworks, web portals, monitoring solutions, virtual terminals and test tools. His work included payment-security specifications, PIN algorithms and CTAP terminal certifications.

At Intersolve, Martin extended loyalty, gift-card, coupon and voucher solutions. He developed service and data adapters for the online switching platform, as well as applications for card generation and import/export processing.

A major project was an online OV-chipkaart switching solution for Dutch public transport. His work also included COM integration, functional designs, documentation, migration plans and acceptance testing.

Martin returned to ICP to design and develop Mimas: a transaction-processing platform for major retailers and value-added services. As lead developer and architect, he was responsible for the full chain, from core processing and database design to APIs, portals, integrations, processing services and operational tooling.

Mimas supported gift cards, loyalty, vouchers, ticketing, lottery, SIM activation, coupons, payments and virtual cards. It integrated terminals, POS systems and international providers through SOAP/XML, REST/JSON, ISO8583, TLV and IFSF.

In 2023, Martin founded CelTom Software as an independent Senior Software Architect and developer. He works on reliable, maintainable and scalable business and transaction systems, from requirements and design through implementation, deployment and continuous improvement.

He is also the architect and developer of Respondit, a modern modular .NET 10 platform for membership administration, event management, access control, self-service and online sales.