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Hi there! I’m Leon Jerinic, a full-stack engineer focused on building scalable software and guiding long-term business transformation. I enjoy architecting clean systems, refactoring frameworks to reduce lock-in, and delivering modular, testable state management and API layers that empower real-time experiences. I’ve led product teams across startups and agencies, delivering checkout flows, platform integrations, and design systems that improve maintainability and velocity. I’m always curious, eager to learn, and motivated to ship value-driven software with a friendly, collaborative approach.…Hi there! I’m Leon Jerinic, a full-stack engineer focused on building scalable software and guiding long-term business transformation. I enjoy architecting clean systems, refactoring frameworks to reduce lock-in, and delivering modular, testable state management and API layers that empower real-time experiences. I’ve led product teams across startups and agencies, delivering checkout flows, platform integrations, and design systems that improve maintainability and velocity. I’m always curious, eager to learn, and motivated to ship value-driven software with a friendly, collaborative approach.

Leon Jerinic

Full Stack Developer, Web Developer, Front-End Developer, +2

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Hi there! I’m Leon Jerinic, a full-stack engineer focused on building scalable software and guiding long-term business transformation. I enjoy architecting clean systems, refactoring frameworks to reduce lock-in, and delivering modular, testable state management and API layers that empower real-time experiences. I’ve led product teams across startups and agencies, delivering checkout flows, platform integrations, and design systems that improve maintainability and velocity. I’m always curious, eager to learn, and motivated to ship value-driven software with a friendly, collaborative approach.…Hi there! I’m Leon Jerinic, a full-stack engineer focused on building scalable software and guiding long-term business transformation. I enjoy architecting clean systems, refactoring frameworks to reduce lock-in, and delivering modular, testable state management and API layers that empower real-time experiences. I’ve led product teams across startups and agencies, delivering checkout flows, platform integrations, and design systems that improve maintainability and velocity. I’m always curious, eager to learn, and motivated to ship value-driven software with a friendly, collaborative approach.

Available to hire

Hi there! I’m Leon Jerinic, a full-stack engineer focused on building scalable software and guiding long-term business transformation. I enjoy architecting clean systems, refactoring frameworks to reduce lock-in, and delivering modular, testable state management and API layers that empower real-time experiences.

I’ve led product teams across startups and agencies, delivering checkout flows, platform integrations, and design systems that improve maintainability and velocity. I’m always curious, eager to learn, and motivated to ship value-driven software with a friendly, collaborative approach.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Language

English

Advanced

Work Experience

Full Stack Engineer at Conway & Co

January 1, 2025 - November 4, 2025

Strategic digital acceleration and growth partner. Led architectural refactoring to achieve clear separation between application logic, framework, and API. Designed an event-driven state management system with hydrations, immutable state handling, and reactive UI updates. Built a modular checkout with multi-step flow and session management, and developed a platform API integration layer with schema validation and data transformation. Established a reusable UI component library and a design system with Storybook for isolated component development and visual QA.

Full Stack Engineer at 9Y Media Group GmbH

January 1, 2025 - January 1, 2025

Led architecture and development for multiple products at a digital agency: e-commerce platform, advertising product, and a legal digital whiteboard. Tech stack included Node.js, React, GraphQL, REST, PostgreSQL, and Elasticsearch. Guided microservices design with an event-driven approach, implemented Apollo Federation for scalable GraphQL APIs, and contributed to iOS/Android apps via React Native.

Full Stack Engineer at StormX Inc.

May 1, 2019 - May 1, 2019

Architected and developed a GraphQL server connecting multiple microservices for a blockchain-based gamified micro-task platform. Built internal React/Redux web app, implemented CI/CD pipelines, Dockerized environments, and contributed to Android and iOS apps with React Native.

Full Stack Engineer at iOLAP Inc.

September 1, 2018 - September 1, 2018

Big-data and analytics consultancy. Designed a microservices platform with Node.js servers, REST and GraphQL APIs, an API gateway with PostgreSQL, and a React-based client. Created React utilities and a component library with lazy-loading and theme support for multiple deployments.

Full Stack Engineer at Webiny Ltd

March 1, 2018 - March 1, 2018

Contributed to Webiny platform development, architecture, and open-source projects. Worked on eCommerce apps and complex administration systems; collaborated with design to enhance client-side experience; built scalable, modular software and deployed across projects.

Full Stack Engineer at Permago LLC

May 1, 2015 - May 1, 2015

Worked on Iceberg.travel platform, a network-for-travelers product; modified existing software, improved interfaces, and performance.

Full Stack Engineer at Kompare online

December 1, 2015 - December 1, 2015

Web platform for comparing and selling insurance policies, telecom packages, and bank loans; participated in architecture and development; contributed to client-side UX improvements.