Application Developer (Web Technologies) (f/m/d)

Application Developer (Web Technologies) (f/m/d) 📍 Vienna, Austria — or fully remote within ±2 hours CET💼 Full-time permanent contract (possible in Austria and Germany) or long-term Freelance (within ±2h CET) What You Will DoBuild and evolve a high-performance, browser-based core application used in real POS and payment environmentsDevelop with pure JavaScript — no frameworks, maximum control, full understanding of browser internalsWork closely with system architects, product managers and a hands-on technical leadership groupContribute to an ongoing re-engineering initiative (microservices on Node.js, with Go planned down the line)Participate in architecture discussions, code reviews and deep-dive technical workshopsDrive performance, reliability and maintainability across the applicationGrow into architecture or technical leadership if this aligns with your ambitions What You BringStrong, in-depth experience with vanilla JavaScript and native browser APIs (DOM, Fetch, WebSocket, Storage, etc.)The ability to build performant applications without relying on frameworksA clean, structured coding style and a strong sense of software qualityExperience with Git workflows, testing methodologies and collaborative review processesA proactive, ownership-driven mindset — you like to take responsibility, not wait for instructions Nice to haveExperience with Node.js, Go or C (microservices, embedded systems, device-level development)Exposure to POS, payment, IoT or hardware-connected softwareUnderstanding of binary or non-JSON communication formatsInterest in re-engineering, system design, scalability and distributed architectures Work modelRemote-first within ±2h CETOptional office days in Vienna (not required)Two on-site team weeks per year in Vienna — travel and accommodation coveredFull-time employment possible for candidates in Austria and GermanyLong-term freelance collaboration possible from any country within ±2h CET Why this role is excitingYou work on engineering challenges that very few browser-based systems faceYou help shape a platform that interacts with real hardware and processes real transactionsYou join a fast-moving company where decisions are made quickly and engineers have influenceYou become part of a culture that values clarity, trust, autonomy and people who genuinely care about their craftIf you want to work on technology that combines browser engineering, device connectivity and real-world impact — this is where it all comes together