Senior Fullstack Engineer

Sytac - Openings; Amsterdam; On-site; EUR 95,000 - 135,000; Full time

Benefits offered by this job

Unlimited Growth Days

The Best Gear

Invest in You

Future Proof

Legendary Trips

Job summary

At Sytac, we seek a Senior Full Stack Software Engineer to join the Payments team in Amsterdam. You will design, build, and evolve applications touching millions of customers, using a containerized Java stack and modern frontend tech.

You will own features end-to-end, mentor peers, and help migrate legacy card systems to a unified platform while advancing a shift-left culture and cross-country collaboration.

Qualifications

• 6+ years of professional software development experience.
• Experience with end-to-end feature delivery and leadership.
• Fluency in English, spoken and written.

Responsibilities

• Design, build, and enhance applications for debit/credit services across issuance, blocking, and PIN requests.
• Lead a big migration of legacy cards to a unified platform across countries.
• Shape new credit card offerings and subscription models within a modern product portfolio.
• Work across the stack with Java, Spring Boot, and frontend tech; own deployments in OpenShift/Kubernetes.

Skills

Mentoring/leadership

System design

Architectural thinking

Communication

English fluency

Tools

Java

Spring Boot

Maven

Azure DevOps

Kafka

Cassandra

Oracle

Lit HTML/Web Components

NPM

OpenShift

Helm

Kubernetes

Docker

Job description

At Sytac, we build high-performing engineering teams for leading organizations. We combine a pragmatic, people-first culture with technical craftsmanship, giving engineers autonomy in real production environments.

For one of our key clients in the Netherlands, a major player in financial services, we are looking for a Senior Full Stack Software Engineer to join their Payments team in Amsterdam. This is a chance to help build the next generation of banking applications — working on systems that touch millions of customers every day — in a modern, shift-left engineering culture built on containerized Java services, cloud-native deployment, and spec-driven, agentic development.

What you’ll do

• Design, build, and enhance applications supporting the full lifecycle of debit and credit card services — from issuance to blocking, replacing cards, adjusting limits, and PIN requests.
• Contribute to a large-scale migration of millions of legacy cards onto a new platform, consolidating microservices and frontends into a single, reusable, product-agnostic solution built for reuse across countries and currencies.
• Help shape new credit card offerings, including subscription-based models, as part of a broader push to modernize the product portfolio.
• Work across the stack — with a focus on backend — using Java, Spring Boot, Maven, Azure DevOps, Kafka, Cassandra, and Oracle, alongside Lit HTML/Web Components and NPM on the frontend.
• Take ownership end-to-end: refine, code, test, and deploy your own work to immutable containers running on OpenShift, using Helm, Kubernetes, and Docker (Compose).
• Act as a technical lead and mentor, while also learning from colleagues across a diverse, multidisciplinary team.
• Share knowledge with the wider engineering organization through documentation, presentations, and workshops, helping shape new standards for how the team works.

What we’re looking for

• 6+ years of professional software development experience, with strong skills in either backend or frontend and solid working knowledge of the other.
• Experience with test automation (e.g. WireMock), continuous delivery, and modern deployment pipelines.
• A track record of leading a software feature end-to-end, from design through deployment.
• Strong reasoning and architectural thinking, with the ability to quickly get up to speed on unfamiliar technical concepts.
• Great communication skills — comfortable acting as a technical sparring partner for business stakeholders as well as engineers.
• Fluency in English, spoken and written.

Nice to have

• Experience working in multidisciplinary, iterative teams.
• A genuine interest in staying current with broader trends in software development and technology.
• Experience mentoring or being mentored within an engineering team.

Life at Sytac

Working at Sytac means joining a community that prioritizes your growth. Our benefits package is designed for flexibility, learning, and adventure:

• Unlimited Growth Days : Enjoy your professional development and Sytac activities!
• The Best Gear : Pick a private laptop (<€4,000) with 50% paid by us, plus a tech budget.
• Invest in You : A €2,400 annual growth budget for training and conferences.
• Future Proof : We contribute 3.75% to your pension.
• Legendary Trips : Join our annual ski trips, beach BBQs, and epic parties!