JS Developer (Mid/Senior)

Piwik PRO & Cookie Information is a technology group building modern solutions in the areas of consent management, analytics, and data activation, with privacy-by-design at the core of everything we do. We help organizations worldwide collect, analyze, and activate data in an ethical, secure, and fully compliant way with global data privacy regulations. Our mission is to prove that privacy-friendly MarTech and compliance solutions can truly enable growth — not stand in its way.We’re currently looking for JavaScript Developer (Mid or Senior) to join our cross-functional Data CIA team. Together, we build and maintain technology for collecting, integrating, and activating user data across websites and mobile applications.Who we’re looking forWe’re looking for people who genuinely enjoy working with JavaScript and don’t limit it to frontend-only tasks. This role requires attention to detail and the ability to step into an existing codebase, understand it, and improve it thoughtfully where it makes sense. Reliability, strong organization, and a sense of ownership really matter here.We value a strong eye for quality, long-term thinking, and open communication – sometimes that means hopping on a call or solving a problem together with a client.For Mid-level developers, we expect the ability to work independently on well-defined tasks while gradually expanding ownership and impact.For Senior-level developers, we expect strong technical ownership, the ability to drive architectural discussions, and active support for other team members through mentoring and high-quality code reviews.The scope of responsibilities and compensation will be aligned with your level of seniority.What you’ll need to thrive in this roleHands-on knowledge and 2+ / 5+ years of experience with JavaScript (we work with ES3–ES5+)Experience with TypeScriptAbility to use browser profiling tools effectivelySolid understanding of REST APIsExperience writing unit and E2E tests (Jest)Familiarity with container environments (Docker)Knowledge of agile development practices and tools (Scrum, Kanban, Jira, GitHub or other Git-based version control systems)Basic understanding of web application security (CSRF, XSS)Good command of English (B2) and Polish (B2)Bonus points if you have…Experience with React (or Angular/Vue)Experience with Node.js and its ecosystemExposure to relational databases (e.g., MySQL)Not sure whether you fit better as a Mid or Senior? Apply anyway – we’ll assess your level during the recruitment process and align the offer accordingly.What you’ll doDevelop, maintain, and optimize JavaScript librariesBuild new integrations and improve existing ones with other systems and toolsCreate and maintain technical documentationProfile and optimize application performanceWrite unit and integration testsWhat you can expect from usCompetitive salary:Mid-level: 11 000 - 20 000 PLNSenior-level: 17 000 - 23 000 PLNFlexible work setup: fully remote from anywhere in the world or from our office in WrocławPersonal growth budget for learning, courses, and industry booksPrivate healthcare (Luxmed)MyBenefit cafeteria platformA fully paid 1-month sabbatical after every 5 years with usInternal referral program with a nice bonus for bringing great people on board“Sharpen the saw” day — a full day dedicated to personal or group projects outside the sprintA strong, supportive team culture focused on collaboration and delivering togetherPlenty of opportunities to share knowledge and learn from experienced teammatesRecruitment processAfter you send us your CV, here’s what the process looks like:Intro call with HR (30–45 min)Deep-dive interview with the team (120 min)Final decision and feedback