Freelance Solution Architect & Software Engineer · Berlin

Backend, cloud and DevOps engineering built to scale — and to run efficiently.

I design and ship reliable backend systems and APIs on AWS, migrate legacy platforms to the cloud, and tighten up performance, cost and delivery pipelines. Independent consultant since 2020, trusted by scale-ups and enterprises across various industries.

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10+ yrsbuilding software
Since 2020independent freelancer
AWS · GCP · Azuremulti-cloud delivery

Track record

Selected clients & projects

A snapshot of who I've worked with as a freelancer and the value delivered on each engagement.

Rackspace Germany & Deloitte Consulting

Solution Architect & Software Engineer · 11/2022 – 06/2026

Led a Rip & Replace migration of a legacy SAP R/3 system to AWS for a German luxury automotive brand. Defined the system architecture, authored and implemented a security concept validated by penetration testing, and shaped feature planning. Major contributions to the backend services and frontend. Built integrations to exchange data with other teams via Kafka and REST and utilize the internal Microsoft EntraID.

AWS
SAP migration
Glue Spark (ETL)
Kafka
Security
MongoDB
Terraform

Klarna Bank AB

Software Engineer · 11/2021 – 06/2022

Replaced an aging monolith responsible for merchant branding information, achieving a lower error rate, better performance and faster merchant onboarding through bulk processing and Jenkins automation. Introduced new quality and review gates — and achieved AWS cost savings with no impact on performance.

AWS
Cost optimization
Nest.js
Kafka
Jenkins
Data pipelines

Ada Health GmbH

DevOps Engineer (AWS & GCP) · 10/2020 – 01/2021

Replicated a GCP setup to AWS to enable efficient multi-cloud, regional deployments across GCP, AWS (later Azure too). Created and migrated reusable Jenkins libraries and templates for consistent, reliable delivery, supported teams through the transition, and evaluated a new observability solution.

Multi-cloud
Terraform
Kubernetes
Jenkins
CI/CD
Observability

leogistics GmbH

Software Engineer · 05/2021 – 10/2021

Part of an independent team building the myleo/dsc logistics cloud platform, developing key customer-facing features with Nest.js and MongoDB.

Nest.js
MongoDB
TypeScript
AWS

Newcon

Founding Engineer · 04/2021 – 06/2022

Founding engineer on a pre-seed startup (6-month acceleration program at REAKTOR.BERLIN) — a platform for conferences and their audiences. Built the product from the ground up on a serverless architecture, combining it with no-code tools to validate and ship the MVP fast.

AWS
Startup
Serverless
No-code
Product engineering

Earlier career

Before starting my own company in 2020, I spent five years building software across e-commerce, healthcare and IoT sector. This and a three year apprenticeship are the foundations my freelance work builds on.

2018 – 2020

Senior Backend Developer · Testo SE & Co. KGaA

Built the Testo Saveris IoT cloud platform (Java/Spring Boot) for quality monitoring. Core member of the "OneOps" task force that unified cloud usage, cut costs and enabled multi-cloud Kubernetes & Terraform deployments. Regular on-call for monitoring systems, kubernetes cluster, and applications.
2017 – 2018

Senior Backend Developer & Tech Lead · docbiz GmbH

Backend engineering and technical leadership on a healthcare booking platform with Java, Spring Boot, AWS and serverless. Primary responsible person, including customer meetings, regular on-call and monitoring.
2015 – 2016

Software Developer & Tech Lead · reBuy reCommerce GmbH

Re-built the e-commerce checkout in a service-oriented architecture (Java/Spring Boot), led frontend integration and i18n (Angular/PHP), and built a Node.js/Solr sitemap generator processing millions of products for SEO.
2012 – 2015

Apprenticeship · Fachinformatiker Anwendungsentwicklung, DRV Bund

Three-year vocational training in application development, including a trainee program at the datacenter company Speedbone GmbH (2014).

Toolbox

Skills & technologies

The technologies I work with, grouped by where they fit in the stack.

Languages

Java
JavaScript / TypeScript
SQL
PHP
Go

Frameworks & runtimes

Spring Boot
Nest.js
Node.js
Angular
React.js
PySpark

Cloud

AWS
GCP
Serverless
Multi-cloud
Network / VPC
IAM
Compliance

DevOps & IaC

Terraform
Docker
Kubernetes
Jenkins
GitLab
CI / CD

Data & messaging

Kafka
MongoDB
SQL / NoSQL
EventBridge / SQS
Lakehouse
RabbitMQ

Architecture & practices

Event-driven systems
Distributed systems
Security concepts
Observability
Performance & cost optimization
Agile

About

Hi, I'm Tim.

I'm a Berlin-based software engineer and solution architect with a strong backend and cloud background. For more than a decade I've successfully designed and built scalable architectures, worked with distributed and event-driven systems, and turned business requirements into technical reality.

Since November 2020 I work as an independent freelancer, partnering with scale-ups and enterprises to deliver secure, efficient and cost-effective software. I care about doing the simple thing well: clean architecture, automated delivery, and infrastructure that doesn't surprise you on the invoice. I'm a fast learner and adapt quickly to new tools and environments.

Beyond code and architecture, I help teams refine their stories, adopt agile ways of working and keep momentum — because great software is as much about how a team works as the technology it uses.

I also use AI where it earns its place. AI-assisted coding to improve delivery speed, and helping clients in adopting AI for the right use cases.

🇩🇪 German (native) · 🇬🇧 English (advanced)

Let's talk

Have a project in mind?

Whether it's a cloud migration, a backend that needs to scale, a delivery pipeline to tame, or an experienced engineer to fill the gap — tell me what you're working on or need.

hi@timgatzemeier.me LinkedIn GitHub

What I do

Services

A focused set of skills, sharpened across banking, e-commerce, IoT, logistics and enterprise migrations.

Backend & API development

Robust, well-tested services and documented APIs — from greenfield builds to replacing aging monoliths or simply continuous integration.

AWS & cloud architecture

Designing scalable, secure cloud architectures — from re-platforming to full rebuilds. Zero-Trust and principle of least privilege in mind.

Optimization

Cutting cloud spend and latency without sacrificing reliability — measurable wins through profiling, right-sizing and smarter data flows.

DevOps & CI / CD

Reusable pipelines and infrastructure as code with Terraform (IaC), Jenkins and GitLab CI — plus automated, containerized deployments to anywhere.

Event-driven & distributed systems

Designing resilient, decoupled systems and event-driven data pipelines - integrating cleanly across teams or feeding analytics platforms.

Agile enablement & story refinement

Refining backlogs and user stories, promoting agile ways of working, and turning fuzzy requirements into shippable specs.