Application Developer (Web Technologies) (fmd)

Youre an engineer who wants to build software that actually matters not another layer of abstraction but real technology used in real environments.

You want to work on a product where your code interacts directly with devices processes high-volume transactions and still runs entirely in the browser.

And youre looking for a place where strong engineering principles autonomy and fast decision cycles are part of the daily routine not just buzzwords.

Our client is a fast-growing European SaaS provider in the payment and POS technology space headquartered in Vienna Austria. Its browser-based platform powers real-time payment flows device interactions and business operations for thousands of merchants.

To strengthen the core team we are looking for an experienced developer who thrives in an environment where people move fast own their work and shape technology that has real-world impact.

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 do

Build and evolve a high-performance browser-based core application used in real POS and payment environments

Develop with pure JavaScript no frameworks maximum control full understanding of browser internals

Work closely with system architects product managers and a hands-on technical leadership group

Contribute to an ongoing re-engineering initiative (microservices on with Go planned down the line)

Participate in architecture discussions code reviews and deep-dive technical workshops

Drive performance reliability and maintainability across the application

Grow into architecture or technical leadership if this aligns with your ambitions

What you bring

Strong in-depth experience with vanilla JavaScript and native browser APIs (DOM Fetch WebSocket Storage etc.)

The ability to build performant applications without relying on frameworks

A clean structured coding style and a strong sense of software quality

Experience with Git workflows testing methodologies and collaborative review processes

A proactive ownership-driven mindset you like to take responsibility not wait for instructions

Nice to have

Experience with Go or C (microservices embedded systems device-level development)

Exposure to POS payment IoT or hardware-connected software

Understanding of binary or non-JSON communication formats

Interest in re-engineering system design scalability and distributed architectures

Work model

Remote-first within 2h CET

Optional office days in Vienna (not required)

Two on-site team weeks per year in Vienna travel and accommodation covered

Full-time employment possible for candidates in Austria and Germany

Long-term freelance collaboration possible from any country within 2h CET

Why this role is exciting

You work on engineering challenges that very few browser-based systems face

You help shape a platform that interacts with real hardware and processes real transactions

You join a fast-moving company where decisions are made quickly and engineers have influence

You become part of a culture that values clarity trust autonomy and people who genuinely care about their craft

If you want to work on technology that combines browser engineering device connectivity and real-world impact this is where it all comes together