Medior Backend Engineer (Java) — EDI & Carrier Billing

In a world where data is the new gold, decision-makers need the most reliable information at their disposal. That's where we come in.

At CONTAX, we turn shipping data into meaningful information for businesses: multinational goods producers, carmakers, medical equipment manufacturers and many more. If a company ships products, it's our job to make sense of what it costs and how it moves.

The team

You will join the EDI team, a small backend team responsible for how carrier invoices and shipment data enter our platform. We integrate with more than 200 carriers through EDI (e.g. X12 210 invoices), flat files and APIs: we parse, validate and normalize their data so that our customers can audit and analyze their freight spend. Our systems run on Java and AWS and handle tens of thousands of daily requests.

The work is close to the business: when a carrier changes a file format or sends unexpected data, our customers feel it. We care about outcomes, not only about closing tickets.

What you will do

• Maintain and evolve existing Java services and carrier integrations: new mappings, format changes, improvements to existing flows.
• Investigate and fix production issues, from data errors in carrier files to defects in our services.
• Build new features in the integration and billing pipeline.
• Own a functional area and shape its design, within a technical direction set by the team's tech lead.
• Suggest improvements to how the team builds and runs software.

What to expect

• First months: mostly maintenance and production support. It's the fastest way to learn the system and the domain.
• After onboarding: maintenance is shared across the whole team. Our current estimate is roughly 60% maintaining and evolving existing systems, 40% new development and design.
• What may change: we are restructuring parts of the codebase and using AI tooling to reduce maintenance cost. If this works, the share of new development and design grows, but we can't promise it yet.

What this role is not

This is not a lead or architect role. You will have real ownership and influence over your area, but the overall technical direction of the team is set by the tech lead and the team. If you are looking mainly for architecture or technical leadership, this role is probably not the right fit.

What we're looking for

Required

• 3+ years of experience building and running backend systems in production.
• Strong proficiency with Java (Spring Boot).
• Experience with relational databases.
• Experience designing, implementing and consuming REST APIs.
• Genuine interest in maintaining and improving existing systems, not only building new ones.
• Clear written and verbal communication in English.
• The right to work in the Netherlands. We are unable to offer visa sponsorship.

Nice to have

• Experience with EDI, data integration or file-based data pipelines. No prior EDI experience is required: we'll teach you the domain.
• Experience with cloud-based applications, preferably AWS.
• Experience with messaging systems (RabbitMQ, Kafka).
• Experience with enterprise software.
• TypeScript (Node.js), SAP BTP or Kubernetes.

Our stack

Java (Spring Boot) · AWS · RabbitMQ · PostgreSQL and SAP HANA · Redis · Docker · Bitbucket and Jira

What we offer

Compensation. The salary for this position starts at approximately €57k gross per year, including holiday allowance, with final compensation based on experience and qualifications

Work-life balance. A fully-remote working model within the Netherlands and flexible working hours.

Your own device. A bring-your-own-device compensation, so you can choose the technology that makes you most productive.

Pension plan. A pension scheme, so you build up retirement savings from day one.

Location

The role is based in Utrecht, Netherlands. We only consider applicants who live in the Netherlands, or are able to relocate, and already have the right to work here.