We’re looking for a Junior Fullstack Software Engineer to join our crew. Together with your team, you’ll help shape the transition from legacy to brand-new architecture, build secure and scalable solutions, and explore modern tooling in an international environment.

No, you don’t have to be this very experienced engineer yet. We are looking for an eager colleague who wants to learn how IT in banking works and who is willing to learn from (and with) us!

You will be working at the heart of what we do and you can learn a lot! Thanks to you and your colleagues, WTSS ensures that our client banks rely on strong encryption, safe systems, reliable authentication flows, and modern software that’s built to last.You’ll be diving into cryptographic hashing, secure encryption, backend development (C#) and building smart components that power our platforms. If you enjoy front-end (React & Typescript) as well, there’s plenty you can pick up as you grow into a fullstack engineer.

Who is WTSS

Banks process millions of transactions every single day. In our modern world, they’re absolutely essential. That’s why identifying, assessing, and solving incidents as quickly as possible is critical for them. And that’s where WTSS comes in.

WTSS is an independent FinTech partner to banks around the globe. We act as a friendly, patient, and risk-free pilot customer, so banks don’t have to test on their real clients. We design structured test journeys (manual and automated) across all possible environments to catch and fix issues before they turn into major risks.

We’re a small, highly technical team of 15, supporting some of the world’s biggest banks. All from our HQ in Rotterdam. We call ourselves ethical techies: curious tech savys who love breaking things, just so we can build them back up, but than better. Incidents don’t impress us. Because of our passion and knowledge about the things we do, we create great value when things don't go as expected.

As our junior software engineer colleague you’ll be surrounded by senior engineers, given lots of freedom, and encouraged to innovate wherever you see opportunities.

So what does your day-to-day look like?

• Building, improving, and maintaining the backend services of our portal and API’s

• Working with cryptographic hashing, encryption, and secure-by-design principles

• Contributing to architectural discussions and conceptual technical choices

• Collaborating closely with senior engineers who guide your professional growth

• Expect lots of variety, modern tech, and a playground where you can learn, experiment, and master fullstack engineering

Do you love tech as much as we do?

You’ll be joining a team of people who simply love tech. We’re the ones our families call when the printer won’t connect or the WiFi suddenly disappears. Some of us install a fresh OS on a Saturday just for fun. Voluntarily.

If you’ve got that same curiosity for new tools, languages, and tinkering, we’d love to hear from you.

What we hope you bring:

• Experience with frontend and backend development is required (internships as well!)

• Interest in hashing, cryptography, or security-driven engineering

• Strong conceptual thinking and a structured mindset

• You learn fast and don’t mind limited documentation. You like exploring

• Ambition to work in banking, fintech, or payments? Let’s go!

What we offer:

• A good salary!

• Start with a 1-year contract, working towards a permanent contract

• A diverse role in a growing, tech-minded, no-nonsense team

• Hybrid setup: work from our Rotterdam HQ and from home

• We offer a good pension plan, travel allowance, homework allowance