Ivan Kormilitsyn

Senior Full Stack Engineer with 10+ years of experience building scalable backend services, AI-enabled products, fintech platforms, and e-commerce applications. Currently lead a four-person engineering team focused on AI services, Python backend development, LLM workflows, and distributed systems. Strong experience with Python, Java, Node.js, PHP, PostgreSQL, MongoDB, AWS, and microservices.

Additional full stack experience with React, Next.js, Angular, and TypeScript. Skilled in technical design, performance optimization, code reviews, cloud deployment, production monitoring, and reliable product delivery.

Senior Full Stack Developer - Global Fashion Group - Germany, Remote

(2020-07)

• Lead a team of four engineers focused on AI services, backend architecture, technical planning, code quality, and production delivery.
• Design and develop e-commerce and internal backend services using Python (Django & Flask), Java (Spring Boot), PostgreSQL, and AWS.
• Built LLM and NLP workflows with Hugging Face Transformers, supporting more than 10,000 requests per day across internal and customer-facing applications.
• Optimized AI inference and backend processing, reducing average response time by approximately 20%.
• Redesigned asynchronous processing and caching workflows, reducing repeated backend operations by 30%.
• Improved service reliability through stronger monitoring, error handling, deployment controls, and production troubleshooting.
• Partner with product managers and engineers to translate business requirements into technical plans, system designs, and delivery milestones.
• Maintain selected customer-facing features using React, Next.js, and TypeScript, connecting frontend workflows with backend and AI services.

Full Stack Developer - Lokalise - Latvia, Remote

(2018-08 - 2020-06)

• Built end-to-end localization workflows using PHP, Node.js, React, MySQL, and Redis, covering file upload, parsing, translation editing, validation, and export.
• Engineered parsers for JSON, XML, YAML, iOS, and Android resource files, handling nested structures, encoding problems, placeholders, pluralization, and malformed customer data.
• Optimized file-processing workflows for multilingual projects containing more than 5,000 translation keys.
• Improved the React translation editor and supporting backend APIs, reducing response time by approximately 20% when filtering and updating large projects.
• Built integrations with GitHub, GitLab, and Bitbucket using webhooks, REST APIs, background jobs, and command-line workflows, supporting more than 10 repository synchronizations per day.
• Designed asynchronous processing and Redis caching workflows that reduced repeated database operations by 25%.
• Improved retry handling and background-job reliability for file-processing and repository synchronization workflows.
• Worked across frontend, backend, database, and integration layers to diagnose customer issues and deliver production fixes.

Full Stack Developer - YayPay - Ukraine

(2016-07 - 2018-08)

• Developed fintech user interfaces using React, Redux, JavaScript, HTML5, and CSS3 for financial and accounts-receivable workflows.
• Built backend functionality using Node.js, REST APIs, and MongoDB, connecting financial data with customer-facing applications.
• Delivered and maintained application functionality supporting approximately 100,000 users.
• Improved frontend performance and Redux state management, reducing page-loading time by approximately 20%.
• Optimized database queries and backend processing to improve API responsiveness and application stability.
• Added input validation, centralized error handling, and automated tests to reduce production defects and simplify troubleshooting.
• Maintained functionality across browser interfaces, API layers, business logic, and database integrations.
• Collaborated with product and engineering teams to investigate financial workflow issues and deliver reliable production releases.

Bachelor's Degree - Computer Science - Kharkiv National University of Radio Electronics (2012 - 2016)