We are looking for a Senior Full-stack (React and Next.js) developer with 4+ years of experience in Web programming for a successful web project in the health industry in the USA.REQUIREMENTS:MUST HAVE4+ years of experience in developing complex Web solutionsExtensive general knowledge of JavaScript (Vanilla.js, React.js, Typescript, Next.js, Node.js )English level — at least Intermediate StrongWILL BE A PLUSExperience with Three.js and 3D rendering in the browserFamiliarity with Pyodide or Python running in web environmentsKnowledge of GCP services like Cloud Functions, Firestore, or App EnginePrevious Data Engineering experience might be a plusRESPONSIBILITIES:Develop and maintain web applications using JavaScript/TypeScript (Node.js, React.js / Next.js).Design, implement, and maintain scalable APIs and backend services.Integrate and optimize search with Algolia, real-time data fetching with SWR, and advanced 3D rendering with Three.js.Leverage Pyodide to run Python in-browser where needed.Work with GCP services for deployment, storage, and scalability.Write clean, maintainable, and well-documented code.Participate in agile ceremonies, code reviews, and continuous improvement efforts.Ensure performance, scalability, and accessibility best practices are followed.ABOUT PROJECTOur client is a software company in the USA.PRODUCTThe project focuses on reconstructing complex neuronal structures by analyzing ultra-high-resolution microscopy data, capturing intricate details of brain cells and their connections. Using advanced 3D deep learning architectures, the system processes petabyte-scale volumetric datasets to uncover biological patterns at an unprecedented scale. This platform is transforming how researchers explore the brain, accelerating scientific discovery and enabling a deeper understanding of neural systems across the globe. Its backbone combines powerful computer vision pipelines with scalable infrastructure built for performance and precision.Interview Stages1-st stage — Call with Recruiter (30 minutes)2-nd stage — Interview with our Engineer and Recruiter (1 hour)3-rd stage — Client interviewOur BenefitsProjects with a modern JS stack (React.js, React Native, Vue.js, Angular, Node.js)Strong JavaScript community at the companyWork from anywhere (fully remotely or in our offices in Lviv, Kyiv or Krakow)Paid vacations and sick leaves, additional days offEducation: regular tech talks, educational courses, paid certifications, English classesOne of the best IT employers in Lviv based on DOU ratingRecuiter Anastasiya Matveyeva