Сергей Коваленко

Senior Full-stack Developer with 8 years of commercial web development experience across PHP/OOP, React, TypeScript, MySQL, REST APIs, WordPress/WooCommerce and around 2 years of hands-on Laravel work within commercial full-stack development. Laravel experience includes routing, controllers, Eloquent ORM, migrations, validation, authentication, REST API development and backend business logic. On the frontend, delivered two production React products: KotoEnglish - a large React 18/TypeScript/Vite educational SPA using Redux Toolkit, RTK Query and React Router - and a certified IQ Test built with React and Next.js.

Strong end-to-end ownership covers API integrations, authentication/SSO, production releases, performance and technical troubleshooting.

Senior Full-stack Developer / PHP, Laravel & React Engineer - Impletech.de - Remote, Germany

(2021-05 - 2026-08)

• Delivered 30+ major feature streams, releases and production improvements across education, eCommerce, automotive, healthcare and professional-services products.
• Worked on two commercial React products: the large KotoEnglish educational platform and a certified IQ Test application.
• Developed and maintained KotoEnglish using React 18, TypeScript, Vite, Redux Toolkit, RTK Query, React Router, Formik/Yup, Firebase, i18next and SCSS Modules.
• Built the certified IQ Test with React and Next.js, including reusable components, multi-step testing flows, validation, responsive layouts, state handling and backend/API integration.
• Accumulated around 2 years of hands-on Laravel work within commercial full-stack development, including routing, controllers, Eloquent ORM, migrations, validation, authentication, REST APIs and backend business logic.
• Designed PHP/OOP backend functionality with MySQL, REST APIs, authentication/SSO, payment flows, third-party integrations, cron automation and data synchronisation.
• Developed and maintained WordPress/WooCommerce/ACF platforms with custom modules, admin tools, editorial workflows and complex business rules.
• Managed staging and production releases, debugging, regression checks, Core Web Vitals, Cloudflare/CDN and technical SEO; contributed to technical decisions and mentored junior developers.

Full-stack Web Developer (Contract) - eKreative - Cherkasy, Ukraine - Remote

(2020-03 - 2020-08)

• Worked on commercial WordPress and Drupal projects, implementing PHP changes, templates, structured content, forms, integrations and maintenance fixes.
• Supported responsive frontend delivery with HTML, CSS, JavaScript and smaller React-oriented tasks; performed cross-browser QA and production maintenance.

WordPress / PHP Developer - Global Teams - Remote

(2020-11 - 2021-05)

• Developed a healthcare WooCommerce platform with prescription purchasing rules, payment integrations and custom user/account workflows.
• Implemented checkout, administration and responsive frontend functionality with attention to security and production stability.

Full-stack Web Developer - Webkitchen Design - Kyiv, Ukraine

(2019-12 - 2020-11)

• Built eCommerce and business platforms with PHP, JavaScript, custom CMS functionality and responsive frontend components.
• Developed a currency-exchange platform with scheduled rate synchronisation and automated data processing.

Full-stack Web Developer - AUKS - Kyiv, Ukraine

(2018-10 - 2019-10)

• Delivered PHP/CMS development and reusable cross-browser HTML/CSS/JavaScript interfaces for business websites.

Specialist - Process Control Automation - Igor Sikorsky Kyiv Polytechnic Institute