Senior fullstack java engineer

Vacant; Amsterdam; Hybrid; EUR 90,000 - 120,000; Full time

Job summary

JET in Amsterdam is seeking an experienced engineer to consolidate fragmented partner data into a global event-driven architecture. You will break down monolithic apps into microservices using Java/Spring and .NET, and help build tooling for operations while collaborating across teams.

You will design scalable services, mentor junior developers, and contribute to API and event contracts, AWS deployments, Docker/Kubernetes pipelines, and modern testing practices to ensure robust, observable

Qualifications

• Backend engineering experience with event-driven microservices.
• Experience with Java/Spring or C#/.NET stacks.
• Knowledge of API/Event contracts and messaging queues (Kafka).
• Hands-on with AWS, Docker, Kubernetes and CI/CD tooling.
• Familiarity with OpenAPI/AsyncAPI and observability tools.

Responsibilities

• Design and implement high-performance, scalable event-driven microservices for the partner domain.
• Partner with product teams to translate requirements into technical specifications, and align with cross-functional teams on API/Event contracts (e.g., OpenAPI, AsyncAPI, Confluent).
• Write clean, efficient, and well-documented code while actively mentoring junior developers and driving code reviews to ensure system maintainability.
• Maintain, investigate, and document the revenue-driving legacy platform, acting quickly to debug and resolve any operational issues.
• Proactively explore emerging technologies and AI-driven tools to automate repetitive tasks, simplify full-stack complexities, and elevate overall code quality.
• Actively participate in team brainstorming sessions, communicate progress on complex features, and remain open to learning and innersourcing across new tech stacks.

Skills

Event-driven design

Java Spring

C# / .NET

Microservices

API contracts

OpenAPI

AsyncAPI

Kafka

AWS

CI/CD

Testing

Tools

Docker

Kubernetes

Helm charts

AWS

CI/CD pipelines

OpenTelemetry

Datadog

Testcontainers

Git

Job description

About this role

We are seeking a motivated and experienced engineer to join our team as we consolidate fragmented partner data into a global event-driven architecture. You'll help build tooling that empowers our operations team to manage restaurant partners, breaking down monolithic .NET applications into microservices using Java Spring Framework and Kubernetes. We are big on communication, collaboration and innersourcing across teams.

• Please note that this position is located in Amsterdam (3 days a week from our Amsterdam office and 2 days working from home).

These are some of the key components to the position:

• Design and implement high-performance, highly scalable, event-driven microservices for the partner domain.
• Partner with product teams to translate requirements into technical specifications, and align with cross-functional teams on API/Event contracts (e.g., OpenAPI, AsyncAPI, Confluent).
• Write clean, efficient, and well-documented code while actively mentoring junior developers and driving code reviews to ensure system maintainability.
• Maintain, investigate, and document the revenue-driving legacy platform, acting quickly to debug and resolve any operational issues.
• Proactively explore emerging technologies and AI-driven tools to automate repetitive tasks, simplify full-stack complexities, and elevate overall code quality.
• Actively participate in team brainstorming sessions, communicate progress on complex features, and remain open to learning and innersourcing across new tech stacks.

What will you bring to the team?

• In-depth knowledge of backend ecosystems (Java/Spring Framework OR C#/.Net) and design patterns, with expertise building event-driven microservices using message queues (e.g., Apache Kafka, AWS SNS/SQS).
• Experience in full-stack development, including proficiency in modern front-end frameworks (such as Vue, React, etc.).
• Hands-on experience with AWS, CI/CD pipelines, Docker, Kubernetes, and Helm charts, alongside working knowledge of relational (MySQL) and NoSQL databases.
• Strong background in modern frontend and backend testing frameworks (e.g., JUnit, Testcontainers) and distributed tracing for microservices (e.g., OpenTelemetry, Datadog).
• Hands-on experience with Amazon Web Services (AWS), DevOps practices, CI/CD pipelines, Docker, Kubernetes, and Helm charts.
• Familiarity with PHP, broad exposure across multiple backend ecosystems (Java, .NET), and experience with cybersecurity practices.

At JET, this is how we play

Our teams forge connections internally and work with some of the best-known brands on the planet, giving us truly international impact in a dynamic environment. Being the best at what we do isn’t just about delivering on our strategy. It's a competition for something incredibly valuable – our customers' choice. Every time a customer decides where to order, they're picking a side. At the heart of the JET Customer League are our values and behaviours. They guide every interaction, every decision, every innovation. These are the actions we need to perform consistently and brilliantly, to surpass the competition and earn our customers’ loyalty, again and again. Fun, fast-paced and supportive, the JET culture is about movement, growth, helping one another to succeed and celebrating wins. By truly living our values and embodying our behaviours, we’re building a customer-first culture which enables us to stay one step ahead of the competition.

Inclusion, Diversity & Belonging

What else are we delivering?