Andreas Steffan
Lead Developer
Experience
Lead Developer
Software
Prototyping CMIS adapter for document management system
Skills: Azure, Terraform, Azure DevOps, Azure Container Apps, Azure Monitor, OpenTelemetry, Docker, TestContainers, Spring Boot, GraalVM, OpenAPI, Cucumber
- Extended the document management system with a standard CMIS (Content Management Interoperability Services) interface
- Implemented CMIS core services such as navigation, access rights, search, CRUD operations, and versioning in Java
- Built on RESTful / OpenAPI services
- Delivered as a fat-jar and native container image
- Deployed on-premises and serverless as an Azure Container Application with Terraform
- Improved team autonomy through infrastructure engineering and short feedback loops
- Observability with OpenTelemetry, Azure Monitor, and Azure Logic Apps
- Introduced Terraform and trunk-based development processes
- Quality assurance with BDD tests implemented in C# using SpecFlow and Testcontainers
- Azure DevOps pipeline integration tests
- Established cloud deployment processes
- Conducted cloud and Terraform training for staff
- Secret ingredient: coffee as an integral part of the development process
Lead Developer Chaos
Public Sector
Prototyping chaos engineering
Skills: Kubernetes, LitmusChaos, Argo Workflows, GitOps, Flux, Terraform, Istio, Kube-Prometheus Stack, Loki, Nix
- Built a chaos engineering environment with LitmusChaos
- Implemented observability with the Prometheus stack
- Created chaos workflows with Argo Workflows for two applications to gain basic understanding of chaos engineering
- Introduced disturbances: latency and service outages
- Ultimate goal: improve application resilience.
Lead Developer/Architect
Insurance
Established OpenShift environments with GitOps change processes on-premises
Skills: vSphere, OpenShift, Kubernetes, GitOps, Argo CD, Terraform, Nix, GitLab, Datadog, AWS ECR
- Designed on-premises OpenShift (OKD) Kubernetes cluster environments
- Declarative provisioning on vSphere using Terraform, Argo CD, and Nix
- Security-driven isolation of environments (sandbox, dev, int) with separate subnets per cluster
- Integrated Argo CD and Terraform with one Argo CD instance per cluster
- Provided Terraform execution environment through Nix
- Observability with Datadog and Prometheus stack
- Provided image registry via AWS ECR
- Staff training
Lead Developer Continuous Delivery
Food
Implemented GitOps processes on AWS, Kubernetes, and Terraform
Skills: AWS, Kubernetes, Amazon EKS, GitOps, Flux, Terraform, GitHub, Slack, Datadog, Traefik, Amazon SNS/SQS
- Designed and implemented GitOps deployment processes for AWS EKS-based microservices using Flux and Terraform
- Kubernetes integration with AWS IAM
- Implemented continuous integration pipelines with GitHub Actions
- Integrated Flux with Terraform
- Asynchronous inter-service communication via AWS SNS and SQS
- Connected third-party shop catalog eventing via AWS EventBridge
- Implemented observability with Datadog
- Slack integration for alerting and deployment events
- Implemented service mesh with Traefik Enterprise
Lead Developer Cloud Infrastructure
Warehouse Technology
Implemented GCP infrastructure and landing zones
Skills: GCP, Terraform, GitOps, Azure DevOps, Go, ClojureScript, Cloud Functions
- Designed and implemented GCP infrastructure as part of a multi-cloud strategy
- Designed and implemented landing zones
- Implemented deployments with Azure DevOps and Terraform
- Implemented alerting via MS Teams using ClojureScript
- Implemented serverless tagging with Go
- Staff Terraform training
Lead Developer Cloud/Continuous Delivery
Retail
Greenfield setup for continuous delivery and infrastructure
Skills: GCP, GKE, Kubernetes, Terraform, Flux, GitOps, GitHub Actions, Apache Solr, Apigee, Clojure(Script), Spring Boot, Kotlin
- Designed and implemented GitOps change processes for Kubernetes and GCP resources
- Enhanced team autonomy through infrastructure engineering
- Implemented GitOps for Solr resources using Clojure/ClojureScript
- Implemented index feedback via machine learning
- Continuous integration with GitHub Actions
- Operated Solr via operator
- Deployed across three stages
- Implemented k6 load tests for Black Friday and the Super Bowl
- Alerting via OpsGenie, Google Operations, and MS Teams
- Integrated Prometheus with Google Operations metrics
- Implemented fast recovery (criticality) via rebuild/restore/reindex
- Implemented search read cache with GCP Redis
- Implemented canary migration with Apigee
- Staff training in Terraform, Kubernetes, and operations
Lead Developer Continuous Delivery Kubernetes ETL
Finance
Set up continuous delivery for Apache Airflow
Skills: GCP, GKE, Kubernetes, GitHub Actions, helmfile, GitOps, Apache Airflow, Apache Spark
- Deployed on Google Kubernetes Engine (GKE)
- Designed and implemented continuous delivery for Apache Airflow/Spark workloads
- Initially implemented continuous delivery with helmfile, then with Flux
- Implemented CI with GitHub Actions
Platform Engineer
Logistics
Built a cloud platform
Skills: GCP, Open Telekom Cloud, OpenShift, Kubernetes, Terraform, GitOps, Jenkins X platform, Helm, Skaffold, Draft, Docker, GitLab, Nexus, Docker Registry, ChartMuseum, Monocular, Git, GitLab CI, Prometheus, Elasticsearch, Fluentd, Kibana, Python, Go, Clojure
- Established a platform team to relieve feature teams
- Improved application lead times
- Deployed and managed various Kubernetes clusters: OpenShift PaaS, Kubespray + Ansible, Telekom CCE
- Covered disciplines including observability, authentication/authorization (SSO), networking, key management, storage, databases, CI/CD, messaging
- Greenfield build of GCP infrastructure with Terraform, Cloud Build, and GitLab
- Recovered from a major datacenter incident over a holiday weekend in shifts with a war room
Developer/Infrastructure Architect
Mechanical Engineering
Cloud migration and decommissioning on-premises infrastructure
Skills: AWS, Azure AD, vSphere, Office 365, Terraform
- Planned and decommissioned branch vSphere on-premises infrastructure and applications
- Designed and built infrastructure and applications on AWS and Azure
- Migrated services: file service, business applications, terminal servers, Exchange mail server, Netscaler ADC, Veeam Backup
- Migrated VPN
- Built AWS IAM, EC2, Route 53, S3, Lambda, SES, CloudWatch, AWS Backup
- Integrated Azure Active Directory identity provider with MFA
- Set up Office 365 services
Lead Developer Kubernetes Infrastructure
Finance
Built a cloud-native platform on-premises
Skills: Kubernetes, GitOps, Jenkins X, Helm, Skaffold, Draft, Docker, Jenkins, Nexus, Docker Registry, ChartMuseum, Monocular, Git, Prometheus, Elasticsearch, Fluentd, Kibana, vSphere, Go
- Designed and implemented a highly available and scalable on-premises consumer document archive platform with Kubernetes
- Evaluated numerous cloud-native solutions in a short time
- Established a CI/CD process following GitOps principles
- Selected and configured storage, networking, and observability components
Lead Developer Document Management Platform
Finance
Implemented a consumer document archive
Skills: Alfresco, Java, Spring, OpenAPI
- Designed and implemented a headless consumer document archive for multiple millions of users based on Alfresco Content Services and OpenAPI
- Developed functionality for lifecycle, users, metadata extraction, search, transformations, and access control
Lead Developer Content Management
Education
Introduced personal documents online campus
Skills: Java, Alfresco Platform, Spring, Solr, CMIS/REST services, Freemarker, JavaScript, YUI, Java Swing, Groovy, Spock, Maven, MySQL, Git, Yeoman, Grunt, Bower, npm, AngularJS
- Designed and implemented management of personal documents (exams, applications, certificates) for students and faculty in an online campus of a university
- Implemented student lifecycle, document capture, editorial search, student view, and authentication
- Integrated with the website
- Built Linux server infrastructure
Developer Content Management
Pharma
Storage system for incoming and outgoing invoices
Skills: Java, Alfresco Platform, Spring, Spring Security, Solr, REST services, BPMN, JavaScript, YUI, Dojo, Maven, MySQL, Active Directory, Git
- Designed and implemented an invoice storage system based on Alfresco ECM and CMIS
- Replicated content from ERP system
- Implemented search
- Enriched PDF documents with metadata from ERP system
- Reconciled user master data with Active Directory
- Authentication via Active Directory
Lead Developer Content Management
Technical Service
Service workflow for technical inspection and testing services
Skills: Java, Alfresco Platform, Spring, Spring Security, Solr, REST services, Freemarker, JavaScript, YUI, Dojo, Groovy, Spock, Maven, MySQL, Git
- Designed and implemented document management and workflow solution for technical inspection and testing services
- Coordinated contractors and clients as a general contractor for technical services
- Imported service orders via REST interface
- Managed and monitored processes by contractors and clients
- Processes for various document types such as briefings and reports
- Multi-tenant solution with appropriate access control
Lead Developer Content Management
Entertainment
Concert content management
Skills: Java SE/EE, Alfresco Platform, Spring, Spring Security, Lucene, Solr, Freemarker, Groovy, REST web services, JavaScript, YUI, Dojo, Groovy, Spock, Maven, Clojure, MySQL/PostgreSQL, Git, Docker
- Designed and implemented a system for managing concert content (images, audio, video, documents) for various channels (websites, mobile)
- Developed functionality for lifecycle, search, access control, and distribution
- Implemented REST services (for UI and online shop)
- On-premises Linux-based server infrastructure
Grails Application Developer
Mail Order
Sidecar shopping cart
Skills: Groovy, Grails, Spring, jQuery, Spock, Angular, Selenium, Jenkins
- Developed a shared shopping cart application with the Grails framework and Groovy
- Features for group buyers, co-buyers, and employees
- Integrated with surrounding shop system via REST and SOAP interfaces
- Implemented lifecycle for carts and items (replicated), co-buyer master data, and cart merging
- Implemented access control, fraud detection, and email notifications
Lead Developer Content Management
Insurance
Help system for insurance agencies
Skills: Java, Alfresco Platform, Spring, Solr, CMIS/REST services, BPMN, Freemarker, JavaScript, YUI, Java Swing, Groovy, Spock, Maven, MySQL, Git
- Designed and implemented a content management system for online help of insurance agencies using Alfresco ECM
- Provided HTML-based content for about 2,500 agencies in a dedicated (Java desktop) application over VPN
- Developed functionality for lifecycle, in-context editing, content aggregation, search, workflow management, and publishing
Lead Developer Java
Mechanical Engineering
Quotation workflow system for heat exchangers
Skills: AWS, Java SE/EE, Spring, Struts, JSP, JMX, JSR-170 (JCR), Groovy, SOAP and REST web services, Bootstrap, Hibernate, MySQL, SQL Server, JBoss, Tomcat, Alfresco Platform, UML, Git
- Designed and implemented a multi-tenant quotation workflow and marketing application
- Integrated with ERP system
- Tracked quotations
- Managed documents stored in Alfresco ECM
- Integrated automated price calculation system for binding quotes
- Data synchronization with ERP systems
- Set up Linux-based server infrastructure
Lead Developer Infrastructure/Continuous Delivery
Finance
Website relaunch 2003 (before infrastructure was cool)
Skills: Linux, Java EE, RPC/SOAP web services, Orion Application Server, Contelligent Content Management System, Struts, Spring, Hibernate, Lucene, Jive Community, Oracle 9i, Eclipse 3, Ant, CVS, Perl
- Re-implemented the website of an online bank/broker consisting of transactional, market data, member, and public areas
- Built new Linux server and network infrastructure
- Implemented sign-on in the public area
- Components for community, search, member data, form center, and content management
- Communication between components via RPC/SOAP web services
- Responsible for design, implementation, and operation of about 25 Linux systems and networks
Project Manager IT
Software
Skills: Linux, Java EE, Spring, Apple WebObjects, Perl, Shell
- Designed, implemented, and managed various finance sector projects based on Linux, Java EE, and Apple WebObjects
Developer
Software
Skills: Linux, Java EE, Apache Tomcat, Perl, Shell
- Designed and implemented a journalistic image database and marketplace
Summary
- Trust is the foundation of psychological safety and more important than technology.
- Culture is the framework agreement - "... eats Strategy for Breakfast"
- “We Shape Our Buildings; Thereafter They Shape Us”
- One team, one goal
- Change is the only Constant
- Simplicity matters
- Learning is a lifelong journey
Languages
Education
University of Hamburg
Diploma · Physics · Hamburg, Germany
Certifications & licenses
AWS Certified Solutions Architect – Associate
AWS
Alfresco Certified Engineer
Alfresco
Certified Scrum Master
Sun Certified Enterprise Architect
Sun
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