• Hands-on Tech Lead
  • Software Architect
  • Available

Andreas
Berger

I turn complex requirements into sustainable, production-ready software systems. I take full end-to-end ownership — from the first architectural decisions and lines of code to stable, long-term operation in production, whether building critical core components from scratch or modernizing complex legacy systems.

Andreas Berger

Services

Sound technical decisions

Technical Assessment & Target Architecture

In-depth full-stack analysis of existing systems and definition of a clear, actionable modernization roadmap to support informed technical and business decisions.

Request Details
Faster time-to-market

Implementation of Critical Core Components

Hands-on delivery of production-ready reference components, high-performance APIs, and scalable services across the entire stack.

Request Details
Risk reduction

Migration & Technical Modernisation

Controlled replacement of legacy systems through incremental modernization instead of full rewrites, with a strong focus on integration and transition architectures.

Request Details
Technical leadership within the team

Technical Sparring & Enablement

Stronger technical decisions and more capable teams through code reviews, hands-on mentoring, and the establishment of clear full-stack standards.

Request Details
My way of working: "You build it, you run it" End-to-end Ownership from Architecture to Production

I work with full technical ownership. Architectural and technology decisions are made with long-term, 24/7 production operation in mind. Risks are not delegated — they are addressed early through focused prototypes and incremental, production-ready releases.

  • End-to-end ownership: Architecture, backend, APIs, and production operations in one hand.
  • Clarity before action: Structured evaluation of options, including risks and trade-offs.
  • Sustainability: Systems designed to remain stable, maintainable, and free from costly rewrites.

Project Highlights

Selection of projects with focus on measurable economic success.

Energy · Platform Architect · Tech Lead · 2017–2025

Building a Platform for Automated Regulatory Reporting

Replacing manual regulatory reporting with a scalable microservice platform to reliably meet compliance requirements. Platform Architecture End-to-End Technical Ownership Regulatory reporting requirements

The Initial Situation

Regulatory reporting for electricity, heating, and gas consumption was largely handled manually, resulting in significant operational overhead. The existing process focused solely on producing mandatory reports for authorities, while the collected data was not reusable for downstream business or analytical use cases. With a growing number of metering devices, this approach became economically unsustainable and posed a scalability risk.

The Objectives

  • Fully automate regulatory reporting processes
  • Enable on-demand generation of regulatory reports
  • Build a scalable and extensible data platform beyond pure regulatory needs

My Approach

As Tech Lead with full end-to-end responsibility, I designed the overall platform architecture and led its implementation. I defined clear system boundaries for data ingestion, normalization, aggregation, and reporting, ensuring independent scalability, clean separation of concerns, and long-term extensibility.

The Result

Manual reporting processes were completely eliminated and replaced by automated, on-demand generation of regulatory reports. The platform now serves as a scalable data foundation, enabling additional business and analytical use cases beyond mandatory compliance reporting.

~3.000 Metering devices
100% Automated reporting
Production status Live

Technology Stack

Spring Boot OpenAPI Neo4j MQTT Google Cloud Pub/Sub Kubernetes React
Energy · Lead for Database Strategy & Migration (Neo4j) · 2023–2024

Strategic Database Decision & Migration from ArangoDB to Neo4j

Sound technology decision under delivery pressure through a focused proof of concept and a successful graph platform migration. Architecture Decision-Making Migration Risk Reduction Database Strategy

The Initial Situation

As part of a platform migration, an existing ArangoDB-based solution had to be replaced due to rising costs and growing complexity. The strategic choice was between introducing a graph-native database (Neo4j) or adopting a more complex multi-database alternative. This decision had to be validated quickly to avoid delivery delays and long-term architectural risk.

The Objectives

  • Design and implement a focused Neo4j proof of concept for key use cases
  • Perform graph modeling and evaluate performance and maintainability risks
  • Provide a solid, decision-ready foundation for management

My Approach

I evaluated architectural options under significant delivery pressure by designing and implementing a focused proof of concept covering the platform’s core use cases. In parallel, I supported the team in transitioning existing data access logic into a production-ready graph-based model.

The Result

The proof of concept enabled a fast and well-founded architectural decision. Migration risk was significantly reduced, allowing the platform transition to be completed within the committed timeline and without introducing unnecessary complexity.

On time Migration
Hybrid avoided Architecture Stack
Minimized Decision Risk

Technology Stack

Neo4j Cypher Spring Boot JUnit JSON Schema ArangoDB
Telecommunications · Tech Lead · 2013–2014

Legacy Modernization — Replacing Vignette StoryServer Without a Full Rewrite

Controlled replacement of a legacy CMS through runtime integration instead of a high-risk full rewrite. Risk Reduction Cost Optimization Legacy Modernization

The Initial Situation

A legacy CMS caused high and continuously increasing operating and licensing costs and had to be replaced. The originally planned full rewrite exceeded time and budget constraints and introduced additional licensing risks, putting overall project delivery at risk.

The Objectives

  • Replace the legacy CMS within strict time and budget constraints
  • Ensure full functional equivalence in production under significant delivery pressure

My Approach

I challenged the rewrite-based approach and designed an alternative solution that preserved the existing business logic. By executing the legacy templates in a modern application runtime, the dependency on the original CMS runtime was fully removed.

The Result

A full rewrite was avoided, significantly reducing migration effort, risk, and cost. The legacy system was successfully replaced on time and within budget, without introducing new vendor or licensing dependencies.

6 Licenses saved
10.000+ Templates preserved
On time Migration completed

Technology Stack

Java Spring Framework TCL Interpreter (Java-basiert) Apache Tomcat Hibernate Hazelcast

Competencies

Architecture & APIs

  • Full-stack system architectures
  • Microservices & platform architectures
  • REST, GraphQL, OpenAPI
  • API-first & domain-driven design
  • Security & IAM (Keycloak)

Engineering & Core Technologies

  • Java / Kotlin (Spring Boot)
  • TypeScript
  • React & Material UI
  • SQL & NoSQL (Neo4j, InfluxDB)

Cloud & Operations

  • Google Cloud (Pub/Sub, Storage)
  • Docker, Kubernetes, Helm
  • CI/CD pipelines (design & integration)
  • Observability (Prometheus, Grafana)

Testing & Delivery

  • Unit & integration testing
  • BDD (Cucumber)
  • End-to-end testing
  • Agile product delivery (Scrum / Kanban)

Roles & Focus

Hands-on Tech Lead

Overall technical ownership for architecture and delivery. Hands-on implementation of critical components and accountability for quality, delivery reliability, and long-term technical sustainability.

Software Architect

Structuring complex and ambiguous requirements into robust, economically sound architecture concepts with a clear focus on long-term viability.

Technical Bridge

Interface between product and engineering. Clarifying goals, constraints, and risks to enable smooth and predictable delivery.

Enablement & Technical Sparring

Enabling technical decision-makers and teams. Providing guidance on strategic technology decisions, architecture reviews, and best practices.

Education & Certificates

Education

Graduate in Business Information Systems

HTW Dresden
01 Oct 2001 - 30 Nov 2006
Focus: Business Informatics

Certificate

Java-Certificate 1Z0-851 Java Standard Edition 6 Programmer [SCJP]

Oracle · 02 Dec 2011

What clients say

Andreas combines pragmatic problem-solving with a strong overview of complex initiatives. He consistently delivers results and operates at a very high professional level.
Florian P. Client · Platform Project
Andreas played a key role in delivering complex features under significant time pressure. His technical expertise and willingness to share knowledge were critical to the team’s success.
Philipp K. Product Owner · Energy Platform
Andreas analyzes complex problems quickly and delivers robust, sustainable solutions. His architectural thinking significantly improves overall system quality.
Annika K. & Atul M. Engineering Team · Distributed Systems

Pricing & Availability

Projects are billed on a fixed-price basis (scope-based) or as time & materials (EUR 100–150/hour). Discounts may apply for long-term engagements.

Current status: Available  (100% Remote, CET)

Frequently Asked Questions (FAQ)
  • Do you work on-site?
    Currently, I work 100% remotely (CET time zone).
  • Are you insured?
    Professional liability insurance is available upon request.
  • Which industries do you focus on?
    Energy utilities, platform operators, and innovative energy and climate technology companies.

Discuss a Project

Let’s talk about how I can support your team and project.