Andreas Steffan
Lead Developer
Experience
Lead Developer
Software
- Expansion of document management system with standard CMIS (Content Management Interoperability Services) interface
- Implementation of CMIS core services such as navigation, access rights, search, CRUD operations, and versioning in Java
- Implementation based on RESTful / OpenAPI services
- Delivery as fat-jar and native container image
- Deployment on-premises and serverless as Azure Container Application with Terraform
- Improved team autonomy through infrastructure engineering and short feedback loops
- Observability with OpenTelemetry, Azure Monitor, and Azure Logic Apps
- Introduction of Terraform and trunk-based development processes
- Quality assurance with BDD tests in C# using SpecFlow and Testcontainers
- Azure DevOps pipeline integration tests
- Introduction of cloud deployment processes
- Cloud and Terraform training for employees
Lead Chaos Developer
Public
- Set up a chaos engineering environment with LitmusChaos
- Implemented observability with the Prometheus stack
- Implemented chaos workflows with Argo Workflows for two applications to build a basic understanding of chaos engineering
- Introduced disturbances: latency, service outages
- Ultimate goal: improving application resilience
Lead Developer/Architect
Insurance
- Designed on-premises OpenShift (OKD) Kubernetes cluster environments
- Declarative provisioning on vSphere with Terraform, ArgoCD, and Nix
- Security-driven isolation of environments (sandbox, dev, int) with a subnet per cluster
- Integration between ArgoCD and Terraform with one ArgoCD instance per cluster
- Provided Terraform execution environment using Nix
- Observability with Datadog and the Prometheus stack
- Provided image registry through AWS ECR
- Employee training
Lead Developer Continuous Delivery
Food
- Designed and implemented GitOps deployment processes for AWS EKS (Kubernetes)-based microservices with Flux and Terraform
- Kubernetes integration with AWS IAM
- Implemented continuous integration pipelines with GitHub Actions
- Integrated Flux with Terraform
- Inter-service communication mostly asynchronous via AWS SNS and AWS 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
- Designed and implemented GCP infrastructure as part of a multi-cloud strategy
- Designed and implemented landing zones
- Implemented deployment with Azure DevOps and Terraform
- Implemented alerting via MS Teams with ClojureScript
- Implemented serverless tagging with Go
- Employee training on Terraform
Lead Developer Cloud/Continuous Delivery
Retail
- Design and implementation of a GitOps change process for Kubernetes and GCP resources
- Improving team autonomy through infrastructure engineering
- Implementing GitOps for Solr resources using Clojure/ClojureScript
- Implementing index feedback with machine learning
- Continuous integration with GitHub Actions
- Operating Solr via operator
- Deployments across three stages
- Implementing k6 load tests for Black Friday and the Super Bowl
- Alerting with OpsGenie, Google Cloud Operations, and MS Teams
- Integrating Prometheus with Google Cloud Operations metrics
- Implementing fast recovery (critical scenarios) via rebuild / restore / reindex
- Implementing a search read cache with GCP Redis
- Implementing a canary migration with Apigee
- Training team members in Terraform, Kubernetes, and operations
Lead Developer Continuous Delivery Kubernetes ETL
Finance
- Deployment on Google Kubernetes Engine (GKE)
- Designing and implementing continuous delivery for Apache Airflow / Spark workloads
- Implementing continuous delivery first with Helmfile, then with Flux
- Implementing CI with GitHub Actions
Platform Engineer
Logistics
- Building a platform team to support feature teams
- Improving application lead times
- Deploying and operating various Kubernetes clusters: OpenShift PaaS, Kubespray + Ansible, Telekom CCE
- Covering disciplines such as observability, authentication/authorization (SSO), networking, key management, storage, databases, continuous integration/delivery, messaging
- Greenfield creation of GCP infrastructure with Terraform, Cloud Build, and GitLab
- Recovering from a major data center incident over the Pentecost holiday in shifts with a war room
Developer / Infrastructure Architect
Mechanical Engineering
- Planning and decommissioning of a branch vSphere on-premises infrastructure and applications
- Designing and building infrastructure and applications on AWS and Azure
- Migrating services: file service, business applications, terminal servers, Exchange mail server, Netscaler ADC, Veeam Backup
- Migrating VPN
- Setting up AWS IAM, EC2, Route 53, S3, Lambda, SES, CloudWatch, AWS Backup
- Integrating Azure Active Directory as an identity provider with MFA
- Setting up Office 365 services
Lead Developer Kubernetes Infrastructure
Finance
- Designing and implementing a highly available and scalable on-premises platform for the consumer document archive with Kubernetes
- Evaluating numerous cloud-native solutions in a short time
- Setting up a CI/CD process based on GitOps principles
- Selecting and configuring storage, networking, and observability solutions
Lead Developer Document Management Platform
Finance
- Designed and implemented a headless consumer document archive for several million users based on the Alfresco Content Services platform and OpenAPI
- Implemented functionality for lifecycle, users, metadata extraction, search, transformations, and access control
Lead Developer Content Management
Education
- Designed and implemented management of personal documents (exams, applications, certificates) for students and lecturers in an online campus of a university
- Implemented student lifecycle, document capture, search for editorial staff, student view, and authentication
- Integrated into the website
- Set up Linux server infrastructure
Developer Content Management
Pharma
- Designed and implemented an invoice storage system based on Alfresco ECM and CMIS
- Replicated content from the ERP system
- Implemented search
- Enriched PDF documents with metadata from the ERP system
- Matched user master data with Active Directory
- Handled authentication through Active Directory
Lead Developer Content Management
Technical Services
- Designed and implemented document management and workflow solution for technical inspection and testing services
- Coordinated contractors and clients through a general contractor for technical services
- Imported service orders via REST API
- Handled processing and monitoring of a process by contractors and clients
- Set up processes for different document types like briefings and protocols
- Built a multi-tenant solution with proper access control
Lead Developer Content Management
Entertainment
- Designed and implemented a system to manage concert content (images, audio, video, documents) for different channels (websites, mobile)
- Implemented functionality for lifecycle, search, access control, and delivery
- Implemented REST services (for UI and online shop)
- Set up on-premises Linux-based server infrastructure
Grails Application Developer
Mail Order
- Implementation of a shared shopping cart application with the Grails framework and Groovy
- Features for group buyers, co-buyers and employees
- Communication with surrounding shop system via REST and SOAP interfaces
- Implementation of lifecycle for shopping carts and items, co-buyer master data, and merging of shopping carts
- Implementation of access control, fraud detection, and email sending
Lead Developer Content Management
Insurance
- Design and implementation of a content management system for online help for insurance agencies using Alfresco ECM
- Providing HTML-based content to about 2500 agencies in a dedicated Java desktop application over VPN
- Implementation of features for lifecycle, in-context editing, content aggregation, search functions, workflow management, and publishing
Lead Developer Java
Mechanical Engineering
- Design and implementation of a multi-tenant quote workflow and marketing application
- Integration with an ERP system
- Tracking of quotes
- Managing documents in Alfresco ECM
- Integration of a system for automatic price calculation of binding quotes
- Data synchronization with ERP systems
- Setting up Linux-based server infrastructure
Lead Developer Infrastructure/Continuous Delivery
Finance
- New implementation of the website of an online bank/broker including transaction, market data, member, and public areas
- Building new Linux servers and network infrastructure
- Implementing sign-on in the public area
- Components for community, search, member data, form center, and content management
- Communication between components using RPC/SOAP web services
- Responsible for designing and implementing operations for around 25 Linux systems and networks
Project Manager IT
Software
- Design, implementation, and management of various projects in the finance sector based on Linux, Java EE, and Apple WebObjects
Developer
Software
- Design and implementation of a journalistic image database and marketplace
Industries Experience
See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.
Experienced in Manufacturing (12.5 years), Information Technology (8.5 years), Banking and Finance (7 years), Media and Entertainment (6 years), Retail (3 years), and Insurance (2 years).
Business Areas Experience
The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.
Experienced in Information Technology (24 years), Product Development (14.5 years), Marketing (12 years), Operations (5 years), Project Management (5 years), and Quality Assurance (1 year).
Skills
Skill Focus:
- Devops
- Continuous Delivery
- Architecture
- Cloud
- Java
- Spring Boot
- Terraform
- Kubernetes
Methodology/mindset:
- Devops
- Lean
- Agile
- Kanban
- Scrum
- Oo
- Functional
- Tdd
- Bdd
- Patterns
Architecture:
- Humans
- Microservices
- Event Driven
- Domain Driven
- Layered
- Mvc
- C4
Infrastructure:
- Cloud Native
- Kubernetes
- Openshift
- Aws
- Gcp
- Azure
- Linux
- Containers
- Docker
- Serverless
- Service Mesh
- Istio
- Traefik
- Apigee
- Vmware
- Kvm
Protocols:
- Rest
- Openapi
- Graphql
- Rpc
- Grpc
Platforms/languages:
- Java
- Clojure
- Groovy
- Go
- Python
- Javascript
- Shell
Testing:
- Postman/newman
- Insomnia
- Selenium
- Junit
- Mockito
- Gherkin
- Cucumber
- Spock
- Testcontainers
- Property Based
- K6
- Litmuschaos
Ci/cd:
- Gitops
- Argocd
- Flux
- Github Actions
- Azure Devops
- Jenkins
- Jenkins X
- Ansible
- Terraform
- Maven
- Gradle
Libraries/apis/sdks:
- Spring
- Grails
- Jee
- Alfresco
- Bpmn
- Jbpm
- Activiti
- Cmis
Databases:
- Mysql
- Postgresql
- Oracle
- Solr
- Elasticsearch
- Mongodb
Observability:
- Prometheus
- Grafana
- Elk
- Opentelemetry
- Azure Application Insights
- Gcp Monitoring
- Aws Cloudwatch
Eventing/streaming:
- Aws Sns/-sqs
- Gcp Pubsub
- Rabbitmq
- Jms
Security:
- Pki
- Owasp
- Zero Trust
- Oauth2
- Openid Connect
- Saml
- Tls
- Waf
- Gcp Cloud Armor
Mindset:
- Trust Is The Foundation Of Psychological Safety And Is More Important Than Technology.
- Culture Is The Framework Contract – "... Eats Strategy For Breakfast"
- "We Shape Our Buildings; Thereafter They Shape Us"
- One Team, One Goal
- Change Is The Only Constant
- Simplicity Matters
- Learning Lasts A Lifetime
Highlights:
- Discovery Of Devops Culture
- Infrastructure As Code
- Quantum Leap To Cloud Native
- (Re-) Discovery Of Lisp (Clojure)
- Founding Pink Gorilla – A Clojure(script)-based Notebook With Platform Ambitions
Languages
Education
University of Hamburg
Diploma in Physics · Physics · Hamburg, Germany
Certifications & licenses
AWS Certified Solutions Architect – Associate
Alfresco Certified Engineer
Certified Scrum Master
Sun Certified Enterprise Architect
Profile
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