John Roest

Software Engineer

Building systems
that last.

I'm a fullstack software engineer with nearly a decade of experience, currently working at the Netherlands Forensic Institute via Sopra Steria. I specialize in backend architecture with Java and Spring Boot, mobile development with React Native and Swift, and DevOps practices. On this blog I share what I learn along the way.

John Roest

Experience

  • Fullstack DevOps Engineer

    Nederlands Forensisch Instituut · via Sopra Steria

    Jun 2025 — Present
    • Backend development on the Dutch DNA Database in a high-security, mission-critical environment
    • DevOps engineering: CI/CD pipelines, containerization, and OpenShift deployments
    • Implemented contract testing to improve API stability and prevent breaking changes
    • Team lead and primary point of contact for client relations on behalf of Sopra Steria

  • Mobile Developer

    Coöperatie VGZ · via Sopra Steria

    Nov 2021 — Jun 2025
    • Rebuilt the VGZ mobile app from Mendix to React Native and TypeScript
    • Contributed to the architectural design of the application
    • Implemented trunk-based development and runtime validation to reduce bugs
    • Coached and mentored colleagues to improve team performance and knowledge sharing

  • iOS App Developer

    de Volksbank · via Sopra Steria

    Sep 2021 — Dec 2021
    • Developed features for the iOS banking app using Swift and SwiftUI
    • Applied MVVM architecture and security best practices
    • Collaborated with designers, product owners, and backend developers

  • Software Developer

    MoneyMonk B.V.

    Jun 2018 — Mar 2021
    • Developed and released iOS and Android mobile applications
    • Built a new REST API with Spring Boot and Kotlin
    • Contributed to frontend development with React

  • Mobile Developer

    MoneyMonk B.V.

    Jul 2017 — Jun 2018
    • Mobile development for iOS and Android platforms

  • Junior iOS Developer

    MoneyMonk

    Sep 2016 — Jan 2017
    • Built iOS interfaces with UIKit and managed async streams with RxSwift
    • Wrote unit tests and participated in code reviews

Technologies

KotlinJavaSwiftTypeScriptJavaScriptSpring BootReactReact NativeNode.jsNext.jsPostgreSQLMySQLDockerKubernetesElasticSearchAzure DevOpsOpenShiftAngular

Writing