Backend Engineer (Kotlin, Kafka, DevOps) [Interim]

Backend Engineer — IAM Platform Transformation (Kotlin, Kafka, DevOps)

Interim contract | Hybrid (Netherlands, office in the Amsterdam metropolitan area) | Start 1 July 2026, initial term to end of 2026 with possible extension

Our client is a leading European food retailer running one of the most ambitious Identity & Access Management transformations in the sector. Across multiple operating companies and enterprise platforms, they are modernising authentication, authorisation, privileged access, identity governance, and application onboarding on cloud-first, security-by-design foundations. This role sits inside the central IAM engineering team enabling secure, compliant, and highly automated identity services for tens of thousands of colleagues, partners, and applications across Europe.

You join a multidisciplinary engineering team building the platform capabilities that underpin the entire programme. You will work at the intersection of engineering, cybersecurity, and platform enablement — engineering modern IAM services while owning reliability, automation, and operational excellence at enterprise scale. The stack is cloud-native throughout: Azure, microservices on Kubernetes, CI/CD pipelines, Infrastructure as Code, and Kafka-driven integrations, shipped in small increments with continuous delivery.

About Riverflex

Riverflex was founded in Amsterdam and London in 2018, eventually growing into a global team of consultants united by a mission to help courageous leaders drive transformative change. Today, we offer an integrated service through three service pillars: strategy and transformation consulting that Creates Change, talent services that Build Teams, and business-accelerating products that Augment Intelligence. For more information, visit www.riverflex.com.

Responsibilities

You build and maintain scalable microservices in Kotlin/Java that power the IAM transformation landscape.

You design and implement secure backend services across authentication, authorisation, identity lifecycle management, and platform automation.

You engineer reusable APIs and event-driven integrations using Kafka and modern integration patterns.

You contribute to Infrastructure as Code, CI/CD pipelines, observability, and operational monitoring.

You write clean, maintainable, secure code with automated testing built in by default.

You collaborate closely with IAM architects, platform teams, product teams, security engineers, and application teams.

You help modernise legacy IAM integrations toward cloud-native, API-driven architectures.

You support platform reliability and production stability, and contribute to engineering standards, code quality, and security-by-design principles.

You build proofs of concept and feed into platform innovation initiatives.

Job requirements

Must-have:

2–5 years of experience as a Backend Engineer.

Strong hands-on experience with Kotlin and/or Java.

Strong experience with the Spring Framework / Spring Boot.

Solid grounding in REST APIs and microservices architecture.

Experience with PostgreSQL or a comparable relational database.

Familiarity with Kafka and event-driven architectures.

Practical experience with DevOps practices, CI/CD pipelines, and Kubernetes.

Familiarity with Azure cloud services.

Understanding of secure software engineering principles.

Fluent English (written and spoken).

Resident in the Netherlands with the right to work in the EU.

The following are a plus:

Experience with Infrastructure as Code (Terraform, Bicep, or similar).

Background in IAM, cybersecurity, or identity platforms.

Exposure to enterprise-scale transformation programmes.

Why this role

This is enterprise-scale IAM engineering at one of Europe's most recognised retailers — the kind of programme where a single well-designed service touches tens of thousands of users and hundreds of applications. You will work on greenfield modernisation alongside mature, high-change services, with real ownership over the platform you build and a clear runway through the end of 2026 with potential to extend.

Interested in this role? Submit your CV and a brief note on your relevant experience through the Riverflex website or reach out to our talent team directly.