Svitla Systems Inc. is looking for a Principal Front End Engineer for a full-time position (40 hours per week) in Poland. Our client is an online marketing company. We’re looking for someone who wants to work collaboratively with PMs, front-end, and multiple backend teams, driving the newest application features into production and ensuring that the product is moving forward to the delight of the clients. You will be building out the robust UI/UX applications that schedule, optimize, and automate marketing campaigns powered by the data science and machine learning models. The tools you build will communicate across external and internal service APIs to help the clients visualize and interact with their data (millions of users and data points.) You will be part of a distributed front-end team responsible for the front-end applications. You will work closely and coordinate with teams across the stack - front-end, back-end, and across the  micro-services and distributed systems. You should love working with and have a mastery of technologies across the JS ecosystem. You will also receive comprehensive exposure to all aspects of the business, from ML application to how we operate large-scale distributed systems and market and sell the product. The code and ideas you contribute will have a tangible impact on the cumulative work of the team as a whole. You thrive in a small, dynamic team environment and want to make an impact. Overlap till 18-19:00 Polish time.Requirements: 8+ years of experience in front-end development. 5+ years of commercial experience with React. Demonstrable experience setting up and optimizing CI/CD pipelines (e.g., GitHub Actions, GitLab CI) for front-end applications. Deep understanding of the JavaScript ecosystem, including NPM/Yarn/pnpm workflows, dependency management. Experience with tools such as Webpack, Vite, Babel. Experience with Nx or any other tool to work with monorepo (Turbo, Lerna, etc.). Knowledge of TypeScript. Understanding designing and implementing interactive front-end web authoring applications with complex event/state handling, not just UI flows (as an example, document editors like Google Docs or landing page editors like Squarespace). Experience designing and implementing large, scalable web applications. Strong history of cross-team collaboration (front-end/back-end/PM/design/QA) to deliver products. Strong knowledge of HTML and CSS. Understanding overwriting unit tests using frameworks such as JEST & RTL/Cypress/Playwright. Experience using automated integration tests like Playwright and efficiently using their debugging tools to prevent regressions in your work. Experience using IaC tools like Jenkins to automate your projects' building, testing, and delivery. Experience working with a remote/distributed team. Advanced English. Nice to have: Experience with GraphQL. Experience in developing SaaS products. Responsibilities: Engineer front-end content authoring applications to support platform features Work with PMs and designers to implement UI/UX features from mock-ups. Develop the tools for communicating across external and internal service APIs to help the clients visualize and interact with their data (millions of users and data points). Confer with multiple teams to assess project scope and determine requirements and timelines. Maintain build and deployment (CI) pipeline for front-end projects and work collaboratively with the CD team to optimize the developer experience. Coordinate with back-end developers to design and ensure smooth integration of APIs. Implement and maintain front-end infrastructure. Identify performance bottlenecks and architect solutions to improve the application’s build and implementation for the Core Web Vitals and high-frequency customer interactions. Troubleshoot and correct existing software errors. Design and develop automated testing processes. Ensure adequate documentation for your design and implementation. We offer: US and EU projects based on advanced technologies. Competitive compensation based on skills and experience. Regular performance appraisals to support your growth. Flexibility in the workspace, either remote or in our welcoming office. Comprehensive medical insurance after one month. MultiSport card with access to 2500 sports facilities all over Poland Bonuses for recommendations of new employees. Bonuses for article writing, public talks, and other activities. 15 vacation days, 10 national holidays, 10 sick leaves, and family days off. Personalized learning program tailored to your interests and skill development. Free tech webinars and meetups organized by Svitla. Welcome and anniversary presents, gifts for children, and more. Regular corporate events and meetups. Awesome team, friendly and supportive community!