Hans Kruse

2022-present:

Responsible for:

• Spec-driven, AI-assisted migration at scale from Spring Boot 3.5 to 4.1, guarded by EditorConfig, Enforcer, JaCoCo, ArchUnit, OpenRewrite, and Pitest to reduce technical debt and enhance security.
• Migrating Elasticsearch 7.x High-Level REST Client code to the modern fluent/functional elasticsearch-java 8.x library.
• Spec-driven, AI-assisted migration of JUnit 5.x to JUnit 6.1.
• Introducing custom metrics with Micrometer for Elastic Observability.
• Managing HTTP routes, Istio, and other Kubernetes configurations.
• Manually migrating Java codebases step-by-step from Java 8 through Java 25.
• Manually migrating legacy JUnit 3.x test code to JUnit 5.x.
• Introducing Logstash for migration and automated testing workflows.

Also starring as:

• Security Champion conducting threat modeling.
• Winner of multiple hackathons (utilizing Elasticsearch & Logstash).
• Coaching a junior developer up to medior levels.
• Core member of the Java Guild.

2019-2022 (Senior Engineer):

Responsible for:

• Proof of concept and deployment for automated setup of Elastic stack, Grafana, and Prometheus using Ansible and custom Ansible role collections.
• Dockerized Logstash pipeline setups and migration to Elastic Cloud.
• Schema and pipeline management for Elasticsearch using YAML and Jinja templates instead of JSON.
• Refactoring large Ruby-based Logstash filter scripts into modular components.
• Infrastructure documentation, troubleshooting guides, and internal technical presentations.
• Proof-of-concept evaluation for Elastic-Agent adoption.
• Java analytics software maintenance and unit test migrations (JUnit 4 to JUnit 5).
• Mentoring colleagues on parameterized, property-based, and mutation testing practices.

2015-2019 (Research Engineer / Consultant):

Contracted to DNB ID Solutions (Den Norske Bank) to create IDmee—a mobile onboarding solution for financial institutions. Worked within an international team (UK, Norway, Netherlands) delivering technical consulting on ReadID verification integration and developing signed PDF generation/upload services.

Responsible for:

• Designing, developing, and maintaining the Elastic stack data mining pipeline for ReadID (tree-structured keyword index system without full-text search overhead).
• Developing and maintaining Java anonymization libraries for passport chip data.
• Integrating third-party server-side verification web services into ReadID and writing OData REST API documentation.
• Engineering ReadID server software for mobile NFC passport verification and C# Azure Functions.
• Designing and delivering internal Kibana visualization training.
• Mentoring student intern groups and participating in the 2016 Dutch Blockchain Hackathon.

Technologies & Training:

• Technologies: AWS (EC2, S3, SQS), Azure (Functions, Key Vault, Blob Storage), Docker, Ansible, ELK Stack (Elasticsearch, Logstash, Kibana, Beats, Fleet, Elastic-Agent), Java (EE), JavaScript, Lombok, OData, PostgreSQL, SQL Server, Ruby.
• Courses: Elastic Certified Engineer, Jeff Geerling’s Ansible Course, Kubernetes Developer Tutorials.

Engineered Suite4DM—Centric’s document and case management platform for municipal governments.

Responsible for:

• Evaluating and architecting new OData-based web services.
• Conducting technical knowledge-sharing sessions on OData, TypeScript, LINQ, and WCF via presentations and pair programming.
• Coaching junior engineers and guiding teams through legacy code modernization (converting legacy JavaScript to TypeScript and adopting StUF-based web services).
• Providing Tier-3 remote engineering support for complex customer deployments.
• Authoring technical manuals and API reference guides for the core DMS connector.
• Serving as technical consultant on DMS integration for Centric HR & Payroll teams across the Netherlands and Romania.
• Building an integration testing framework for the DMS connector using C# and MSTest property-based testing.
• Developing DMS integrations with VB.NET, SharePoint CSOM/Server-Side Object Model, CMIS, and Intraoffice.
• Optimizing legacy infrastructure performance to support 200+ concurrent active sessions.

Technologies:

• WebAPI, OData, WCF, C#, VB.NET, TypeScript, jQuery, SharePoint CSOM

Courses:

• Coursera Functional Programming Principles in Scala

IKM Engineering specialized in decision-support systems and advanced mathematical modeling.

• Spearheaded company transition to .NET and modern web development architectures; trained local and remote developers in C#.
• Served as Project Lead for a DotNetNuke (DNN) HRM feedback platform built for Royal Haskoning.
• Developed Python/Zope integrations for the international Fliwas flood crisis management project in collaboration with Dutch water boards and Leiner & Wolff GmbH.
• Maintained and optimized Delphi-based predictive algorithms for real estate maintenance and portfolio analysis (AKZO paint analysis).
• Streamlined internal IT infrastructure by migrating legacy services to AWS and Google Cloud.

Telematica Instituut (later Novay) was a Dutch national research center bridging industry and academia through practical software innovation.

Key Projects & Innovations:

• GigaPort Awareness: Developed an interactive presence visualization app mapping staff indoor locations using AJAX long-polling, Google Maps API, and X3D (WebGL predecessor). Presented at ICT Delta Congres.
• Kanalen in Balans: Converted complex Excel financial models into interactive Web Applications using JavaScript and Drupal.
• Secure Networking: Co-developed fiber optic access authentication pipelines leveraging RADIUS, DNSSEC, and SAML.
• Remote Microscopy: Re-engineered secure file transfer protocols for remote electron microscope diagnostics, replacing unreliable messaging queues with FTP over OpenVPN (demonstrated at RAI Amsterdam).
• Second Life Integrations: Built an enterprise demonstration environment connecting virtual worlds with external REST APIs.
• ProRail / NS (Dutch Railways): Built energy-efficient train driving simulators and prototyped location-based transit schedule services for Symbian devices (featured in De Volkskrant).
• Microsoft Research Collaborations: Prototyped early unified communication/presence platforms (later evolved into Lync/Skype for Business) and built PocketPC/Mobile .NET Compact Framework medical assistance tools for Alzheimer’s and stroke patient care.

Board member facilitating civic engagement and local solar energy adoption initiatives.

Assisted computer science lab courses for undergraduate students in C++ programming and system simulation (e.g., Maeslantkering storm surge barrier simulations).