Frontend Developer (HTML/CSS/JS + ReactJS) — Ad Creatives & Integration (Russian/Ukrainian Speaking)

About the Role We're looking for a skilled and reliable Frontend Developer to join our team on a part-time basis. You'll be working on advertising creatives and ad tech integrations — building, maintaining, and troubleshooting ad units across various publisher sites. What You'll Do: - Build ad creatives — Develop static, interactive, and video ad banners from scratch; ensure cross-browser and cross-device compatibility - Maintain existing ad formats — Fix bugs, refactor legacy code, and implement updates based on evolving requirements - Troubleshoot integration issues — Diagnose and resolve rendering, styling, compatibility, and tracking problems on publisher sites Technical Skills: - Strong proficiency in HTML, CSS, and JavaScript - Experience with ReactJS - Understanding of responsive design and cross-browser compatibility - Experience with ad tech or banner development is a plus Soft Skills & Availability: - Responsible, self-motivated, and detail-oriented - Must be reliably available online during agreed working hours — quick communication is essential - Ability to work independently and meet deadlines Language: Fluent in Russian or Ukrainian (required for team communication) Why Join Us - Flexible part-time schedule - Interesting technical challenges in the ad tech space - Long-term collaboration opportunity for the right candidate