E-commerce growth in Central and Eastern Europe has accelerated significantly through the 2020s, and the payment infrastructure supporting that growth has needed to evolve from supporting basic card acceptance to providing the full range of payment methods, BNPL options, and merchant tools that modern e-commerce expects. Montonio was founded in Tallinn in 2018 to build that infrastructure for the CEE market specifically. Its platform offers payment processing, BNPL integration, and merchant commerce tools designed for Baltic and broader Central European e-commerce businesses, with a particular focus on the integration depth and local payment method coverage that international platforms underserve. The company has grown rapidly across Estonia, Latvia, Lithuania, Poland, and other CEE markets, building merchant relationships and product capability in markets where the e-commerce growth opportunity is significant but where the international payment platforms have not invested with the same depth as in Western Europe. In the European payments landscape, the regional specialist model has shown durable competitive advantages in markets where local payment preferences are distinct, and Montonio represents the new generation of CEE payment infrastructure built for the post-2020 e-commerce environment rather than retrofitted from older payment systems.