Middle Software Engineer (React)

Our Client is the leading energy SaaS company delivering highly-technical insights and predictive/prescriptive analytics that empower customers to make decisions that increase profit. ​You would be joining the team developing our premier energy analytics platform. This vacancy requires EU residence. Responsibilities: Maintain and enhance a large-scale React application with a mix of functional and class-based components Optimize application performance, including reducing execution time for heavy or long-running requests Rapidly prototype new features in a React-based web application Influence design and user experience of single-page applications Interact with and develop new microservices backed by document-based databases and GPU-accelerated databases Write unit, integration, and end-to-end tests Stay up to date on the industry trends through self-study, research, and online courses Mentor junior team members Requirements: EU residence 3+ years of software development experience in building web applications using React and Redux Extensive experience with modern web application development tools and libraries Strong understanding of JavaScript (ES2015+) Multiple-years experience writing modern JavaScript (ES2015 and later) code Knowledge and experience with one JavaScript-based bundler (we use webpack) Experience with performance optimization techniques in front-end applications Experience working with large-scale codebases and the ability to navigate complex project structures Experience with Node.js Experience with Docker/Kubernetes Understanding of CI/CD Familiarity with OOP and Agile methodologies Being comfortable managing source code using Git (we use GitHub) Good understanding of data structure and algorithms English level – Upper-Intermediate or higher Will be a plus: Hands-on experience with WebdriverIO Experience with LaunchDarkly Experience in data visualization, using Mapbox, D3, or other JavaScript-based libraries We offer: Remote-first work model with flexible working hours (we provide all equipment) Comfortable and fully equipped offices in Lviv and Rzeszów Competitive compensation with regular performance reviews 18 paid vacation days per year + all state holidays 12 days of paid sick leave per year without a medical certificate + extra paid leave for blood donation Fixed monthly health & wellness compensation, applicable to: medical insurance; fitness and sports activities English, German, and Polish language courses Corporate subscription to learning platforms, regular meetups and webinars Friendly team that values accountability, innovation, teamwork, and customer satisfaction Inclusive environment where everyone feels valued and treated equally. We proudly partner with VeteranHub to support Ukrainian veterans We are committed to supporting Ukraine and actively participate in charity initiatives