About

About Marcel Heers

I am an independent consultant for platform, cloud, security and delivery work. I have run my own practice since 2009, live in Crete, and work with teams across EU time zones.

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In short

Architecture and implementation in one engagement

The same problem shows up in very different environments.

Most of my engagements start where a platform has become a constraint: a migration that keeps slipping, a Kubernetes estate nobody owns end to end, an authorization model that blocks every new product. I join the team, work out which decision actually matters, and stay close to the code until it holds.

Architecture advice on its own usually ends as a document. Implementation on its own tends to rebuild the same problem one layer down. I do both, and most engagements end with the team able to carry on without me.

Education

Computer science, University of Paderborn

I studied computer science at the University of Paderborn and finished a B.Sc. in 2015. My thesis, written at the Fraunhofer Institute for Production Technology, covered a Bluetooth interface for Arduino microcontrollers.

Career

Where I have worked

Fifteen years of client work, newest first.

  • 2025 – 2026 · T-shaped architect, Microsoft-to-Google Workspace migration. European retail group, roughly 600,000 users. I wrote the Go services and the Pulumi providers for Drive, Sites and Groups, plus the GCP infrastructure for provisioning and reconciliation across several business units.
  • 2025 – 2026 · Full-stack engineer, order management system. Food wholesaler. I built the order lifecycle, price calculation, batch tracking with QR codes, PDF invoicing and the warehouse interfaces in Go, Vue and PostgreSQL.
  • 2024 – 2025 · Lead authorization architect, global authorization service. Insurer, roughly 320,000 users. I designed the OPA and Rego policy platform, wrote the Kafka decision-log plugin in Go, moved CI/CD to Dagger and left behind policy tests the team still runs.
  • 2022 – 2024 · Platform architect, data platform on Kubernetes. Sensor and automation manufacturer. I worked on the NiFi, Trino and Pulumi platform, wrote operators, set up Kyverno policies and Cilium networking, and built the self-service path the data teams used.
  • 2024 · Agentic AI prototyping. I built retrieval-augmented assistants and tool-calling workflows with LangChain for SaaS and retail use cases, including live API integrations and document retrieval.
  • 2020 – 2022 · Product and platform engineering, virtual events. I built features for live events with up to 15,000 participants in nine languages, and the per-tenant provisioning with Pulumi across AWS and Hetzner.
  • 2019 – 2020 · Cloud migration and platform hardening. I moved a Java stack from Rancher to AWS, wrote Kubernetes operators for the stateful services, and set up GitOps with Helm and Terraform.
  • 2015 – 2018 · CI/CD, containerization and developer enablement. Manufacturing and logistics clients. I built delivery pipelines and taught Docker, Kubernetes and CI to teams moving off long-lived server estates.

Toolbox

What I build with

The tools change with the problem. These are the ones I have kept using across engagements.

Platform and cloud

  • Kubernetes, including AKS and GKE
  • Pulumi and Terraform
  • Helm, Cilium, Kyverno, cert-manager, vcluster
  • AWS, Azure and Google Cloud

Delivery and security

  • Dagger, GitHub Actions and GitLab CI
  • OPA and Rego policy
  • Vault and External Secrets
  • Trivy, SBOMs and supply-chain checks

Data

  • Apache NiFi and Trino
  • Kafka, PostgreSQL, ClickHouse, BigQuery
  • Dagster and data pipeline orchestration
  • Prometheus and Grafana

Languages and frameworks

  • Go
  • Python
  • TypeScript and JavaScript
  • SQL and Bash
  • Vue and Angular

AI and automation

  • LangChain and retrieval-augmented generation
  • Model Context Protocol integrations
  • Agent workflows against real APIs
  • Automation where it removes repetitive work

Location and languages

Crete, and EU time zones

Location

I live in Crete and work remote-first across EU time zones. On-site workshops and delivery sessions are possible by arrangement.

Languages

I work in German and English, and speak Spanish, Greek and Chinese.

Elsewhere

Start the conversation

Tell me what is stuck

A short note with the context, the constraint and the timing is enough for me to say whether this is a fit.

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