Java developer | Freelance

Company.info Nederland; Amsterdam; Hybrid; EUR 96,000 - 152,000; Full time

Job summary

Company.info Nederland is seeking a Senior Backend Engineer for a six-month freelance assignment in Amsterdam, with hybrid work (2 days on-site). You will design, build and operate production-grade Java/Kotlin services on AWS and Kubernetes, focusing on reliable integrations and observability for onboarding, billing and identity systems.

You will implement event-driven workflows, integrate with Keycloak, Salesforce, SAP and a billing platform, and contribute to architecture decisions, testing

Qualifications

• 7+ years of backend development experience with Java.
• Strong Spring Boot and REST API design skills.
• Experience with event-driven systems, messaging, retries and idempotency.
• Solid SQL and relational database skills.
• Production experience with AWS and Kubernetes.
• Ability to translate business processes into technical solutions.
• Strong communication skills in English.

Responsibilities

• Design, build and operate production-grade services and integrations.
• Build durable workflows in Temporal and design reliable event-driven integrations.
• Develop Spring Boot services in Java and Kotlin on AWS and Kubernetes.
• Integrate with Keycloak, Salesforce, SAP and our billing platform.
• Own what you ship, including testing, monitoring, documentation and production readiness.
• Contribute to architecture decisions, code reviews and knowledge sharing.

Skills

Java

Spring Boot

REST API design

Event-driven systems

SQL

AWS

Kubernetes

English communication

Kotlin

Job description

Functieomschrijving

Do you like solving complex backend problems where reliability really matters? We are looking for an experienced freelance backend engineer to join the Java Engineering Chapter at Company.info for a period of six months.

You will work on the systems that connect customer onboarding, billing, finance and identity. The focus is on reliable integrations and event-driven workflows where correctness, idempotency and observability are critical. You'll help build and improve the services and integrations that power our subscription, billing and identity landscape.

What you will do

As a Senior Backend Engineer, you will design, build and operate production‑grade services and integrations.

You will:

• Build durable workflows in Temporal and design reliable event-driven integrations
• Develop Spring Boot services in Java and Kotlin on AWS and Kubernetes
• Integrate with Keycloak, Salesforce, SAP and our billing platform
• Own what you ship, including testing, monitoring, documentation and production readiness
• Contribute to architecture decisions, code reviews and knowledge sharing

Our tech stack

• Java 21, Kotlin, Python
• Spring Boot, Temporal
• MySQL, PostgreSQL
• AWS (EKS, EventBridge, SQS, S3)
• Kubernetes, Helm, Terraform, GitLab CI
• Keycloak
• Grafana, OpenTelemetry, Micrometer
• JUnit, Testcontainers, LocalStack

Culture and team

You will work alongside Java and Golang engineers in a multicultural environment, collaborating closely with Product, Finance and Commercial Operations. Knowledge sharing, code quality and operational excellence are central to how we work. Our working language is English, and Dutch is not required.

The assignment

• Duration: 6 months, with the possibility of extension
• Hourly rate: TBD
• Start date: ASAP
• Location: Amsterdam (hybrid), 2 days per week on-site
• Availability: 32-40 hours per week

What you bring

• 7+ years of backend development experience with Java
• Strong Spring Boot and REST API design skills
• Experience with event-driven systems, messaging, retries and idempotency
• Solid SQL and relational database skills
• Production experience with AWS and Kubernetes
• Ability to translate business processes into technical solutions
• Strong communication skills in English

Nice to have: Kotlin, Keycloak, OAuth2/OIDC, Salesforce, SAP, billing or subscription platforms.

Diversity

At Company.info, we believe diverse backgrounds, perspectives and experiences make us stronger. We encourage applications from all backgrounds. A social media check is part of the selection process.

About Company.info

Company.info is a leading Dutch business intelligence provider. We collect, manage and deliver company data and insights that help organizations make better decisions in areas such as market research, risk assessment and business development.