The world's largest marketplace for digital entertainment, connecting millions of buyers with verified business sellers across game keys, software, gift cards, and subscriptions. Contributed full-stack marketplace capabilities spanning catalog, checkout, account, and transaction workflows using React, TypeScript, Java/Spring Boot, and PostgreSQL.

Subscription membership for G2A shoppers offering member pricing, Plus Points, monthly rewards, and priority support. Worked on frontend flows, REST integrations, and backend services that connect membership state with checkout and account experiences.

Referral and affiliate program that lets partners earn commission on marketplace purchases and G2A Plus memberships. Built and maintained dashboard-oriented interfaces, tracking workflows, and service integrations for partner performance and payouts.

Seller operations portal for verified business merchants — offer creation, stock and key management, pricing, verification, and sales reporting. Developed scalable APIs and React interfaces supporting high-volume digital-goods operations.

Business-facing marketplace channel with AML-verified sellers, CPS commercial model, and seller APIs for catalog import, pricing, and offer automation. Contributed service integrations, validation, and resilient data exchange across marketplace components.

LLM-powered application workflows for content processing, structured information extraction, and AI-assisted operations. Designed prompt-engineering strategies, output validation, and REST integration of model responses with backend data-processing services.

Retrieval-augmented generation pipelines using document preparation, chunking, embeddings, and semantic retrieval to supply relevant context to language models. Integrated AI pipelines with backend services through structured data processing and resilient error handling.

Self-serve advertising inventory platform for Nordic premium publishers. Advertisers create campaigns, upload creatives, target audiences, and review live reports across sites such as Aftonbladet, SvD, Omni, Klart, and TV.nu. Built React/TypeScript features for data-rich advertising workflows.

Kraków technology hub building products for Nordic media houses and marketplaces — newsroom tools, publishing systems, advertising technology, and classifieds. Contributed full-stack advertising-platform features and Azure-hosted service integrations.

Premium advertising inventory on Sweden's largest news brand. Worked on inventory and campaign interfaces that let advertisers reach Nordic audiences in a trusted editorial context, integrating REST APIs with backend advertising services.

Advertising and inventory features supporting VG, one of Norway's leading news destinations. Developed reusable React components and state-driven interfaces for data-intensive advertising workflows used across Schibsted's Nordic portfolio.

Campaign and inventory tooling for Aftenposten and related Nordic newspaper products. Engineered responsive UI layouts and API integrations connecting frontend features with advertising data and backend business services.

Swiss practice-management platform for therapists — patient records, invoices, appointments, and reminders — with 15,000+ daily users. Delivered a major application feature across React, Redux, MobX, Node.js, and PostgreSQL for natural and alternative medicine practices.

Modular Swiss billing and practice workflows for complementary medicine (Tarif 590), including patient cards, invoicing, and reporting. Implemented end-to-end feature work across UI state, API, and PostgreSQL persistence.

Practice software for Swiss psychotherapy billing (Tarif 581 / 582), covering appointment workflows, documentation, and insurance-aligned invoicing. Coordinated frontend, state management, and backend services for healthcare product requirements.

Interactive landing-page functionality for online casino games at William Hill, delivered from Grand Parade — the company's Kraków technology hub. Implemented interface behavior and user interactions with JavaScript (ES6) and AngularJS.

Kraków engineering hub for William Hill, building betting, gaming, and sportsbook products used by millions of players. Contributed frontend casino-game landing experiences within the existing AngularJS and PHP application architecture.

Live-event platform supporting mobile ordering, point-of-sale, reporting, and inventory management. Designed CMS functionality and backend APIs in PHP and MySQL, connecting administrative tools with operational data and ordering workflows.

End-to-end web solutions for independent clients — custom applications and CMS features in PHP, CodeIgniter, and MySQL, with interactive JavaScript/jQuery interfaces connected to server-side processing.

Client applications extended with Google Maps API and related third-party services, connecting location-aware interfaces with PHP backends and MySQL persistence for local business workflows.

Customizable Facebook applications for brand engagement — quizzes, newsletters, and promotional templates with analytics on fans, geolocation, and campaign performance. Built from the ground up with JavaScript, jQuery, PHP, and MySQL.

Websites and Facebook applications for Polish clients delivered through Premium Consulting's Kraków outsourcing practice. Implemented interactive frontend functionality and PHP/MySQL-backed application features from business and design specifications.