Timm Preetz - Senior Backend-Framework Engineer

Q: Where is Timm based?

Timm is based in Munich, Germany .

Q: What languages does Timm speak?

Timm speaks the following languages: German (Native), English (Advanced), French (Elementary) .

Q: How many years of experience does Timm have?

Timm has at least 16 years of experience. During this time, Timm has worked in at least 15 different roles and for 12 different companies . The average length of individual experience is 1 year and 1 month . Note that Timm may not have shared all experience and actually has more experience.

Q: What is Timm's latest experience?

Timm's most recent position is Senior Backend-Framework Engineer at Serverpod AB .

Q: What companies has Timm worked for in recent years?

In recent years, Timm has worked for Serverpod AB , TELESON Vertriebs GmbH , Mawdoo3 , Buzz , and MySports GmbH & Magicline GmbH .

Q: Which industries is Timm most experienced in?

Timm is most experienced in industries like Information Technology (IT) , Retail , and Professional Services . Timm also has some experience in Energy , Tourism and Hospitality , and Agriculture .

Q: Which business areas is Timm most experienced in?

Timm is most experienced in business areas like Information Technology (IT) , Product Development , and Business Intelligence . Timm also has some experience in Marketing , Operations , and Sales .

Q: Which industries has Timm worked in recently?

Timm has recently worked in industries like Information Technology (IT) , Professional Services , and Agriculture .

Q: Which business areas has Timm worked in recently?

Timm has recently worked in business areas like Information Technology (IT) , Product Development , and Operations .

Recommended expert

Munich, Germany

Experience

Jan 2025 - Jul 2025

7 months

Senior Backend-Framework Engineer

Serverpod AB

Improved the database migration engine to handle more edge cases
Added support for Dart record and container types in the client-server protocol and PostgreSQL data storage
Created the next generation authentication module: overhauling the social login; adding JWT, passkey, and magic link support; supporting legacy accounts in a backwards compatible way

Dec 2023 - Dec 2024

1 year 1 month

Senior Mobile App Developer, Energy supply contract sales & PV app

TELESON Vertriebs GmbH

Built new Flutter mobile app version replacing two separate Android and iOS code bases (porting business logic from Swift and Kotlin)
Added full offline support using local databases (Hive, Floor) and implemented a robust sync framework to update the server once the client regains network access
Set up testing infrastructure and introduced CI workflows with CodeMagic
Sped up client development by auto-generating APIs from the OpenAPI specification
Implemented on-device PDF editing workflows for filling and signing forms

Jul 2023 - Sep 2023

3 months

Senior Full-Stack Developer, Arabic language chat-bot app

Mawdoo3

Built the MVP chat-bot app for the client’s custom Arabic GPT-style LLM using Flutter
Wrote the backend for the app: user management, chat history, interfacing with the gRPC ML API services
Communicated with downstream app and upstream Python-based AI backends via gRPC
Set up CI/CD with deployments to Google Cloud Run from GitHub

Dec 2021 - Jul 2022

8 months

Senior Full-Stack Developer, video conference & collaboration app

Buzz

Extended the cross-platform Flutter app for video conferencing, work chat, and productivity on web, macOS, and an always-on toolbar app
Replaced the single-server backend with a horizontally scalable Go backend that communicated via gRPC
Used PostgreSQL, Redis (including PubSub), and S3 for data storage
Introduced CI/CD with automatic deployment to AWS Fargate/ECS

Jul 2021 - Oct 2023

2 years 4 months

Senior Mobile Developer, fitness studio management software and end-user booking app

MySports GmbH & Magicline GmbH

Supported the release of three new end-user white-label mobile apps using Flutter
Rewrote the white-label apps to share most code between them with OpenAPI
Implemented a new UX and design system
Taught the client’s existing team development best practices
Introduced automated tests to the codebase and steadily increased coverage, ending with a CI/CD flow
Led the development of the new Magicline app for studio personnel from scratch

May 2021 - Present

4 years 11 months

Senior Full-Stack Developer

Toptal, LLC

Listed as a verified senior full-stack developer

Jul 2018 - Nov 2021

3 years 5 months

Developer / Ops, farm workflow-support app

DataHarvest

Brought the app to a release-ready state using Flutter
Set up CI/CD for automatic tests on GitLab runners and releases with CodeMagic
Fixed issues with native dependencies

May 2018 - Jul 2021

3 years 3 months

Flutter Lead Developer – Mobile App

ABOUT YOU GmbH

Completed rewrite of existing native Android and iOS apps in Flutter
Deployed the company’s first backend microservices with Go and gRPC using Docker

May 2018 - Jul 2021

3 years 3 months

Head of Architecture (Shop Applications)

ABOUT YOU GmbH

Saw the new native app written in Flutter through to release as team lead
Migrated code from legacy backends to new services
Prototyped and kickstarted various new projects including backend systems and customizable shop applications for SaaS cloud customers
Engaged in public speaking

May 2018 - Jul 2021

3 years 3 months

Senior Frontend Developer & Team Lead – Mobile Web

ABOUT YOU GmbH

Completely rewrote the existing mobile website in TypeScript, React, Redux, and Redux Saga
Implemented PWA functionalities including service workers and offline capabilities
Optimized performance and ensured responsiveness
Introduced automated UI testing

May 2018 - Jul 2021

3 years 3 months

Technical Sales & Prototyping

ABOUT YOU GmbH

Consulted on various smaller projects inside the company including technical sales and prototyping for the emerging SaaS/Cloud business SCAYLE
Served as contact person for backend development and architectural questions

Oct 2017 - Apr 2018

7 months

Game Developer, HTML5 Transpilation

Goodgame Studios & Altigi GmbH

Ported Flash-based browser games to HTML5 by improving tooling to transpile AS3 to TypeScript
Developed a Selenium-based testing setup to automate cross-browser tests
Improved game performance by replacing slow parts in core libraries

Sep 2015 - Sep 2017

2 years 1 month

Team Lead UI Components

XaaSify Technologies GmbH

Led migration of a customer-facing realtime application from jQuery to React using a Flux architecture and event-based client-server communication
Implemented a pull-request based workflow with CI oversight to maintain standards
Created internal Node.js tools for dependency management, unit testing, visual diffs, and example runner/playground
Designed a new component-based software development architecture for upcoming major projects

Sep 2012 - Feb 2016

3 years 6 months

Co-Founder, Software Developer

Lunados UG (haftungsbeschränkt)

Provided custom development and consulting to help e-commerce platforms increase reach and optimize offers using competitor analysis
Built a fully automated system on Google App Engine and Azure to track hotel prices on competing platforms
Developed GROWTH-Project to dynamically optimize landing pages and promote deals with SEA campaigns
Created SEO-Logalizer in-house tool to analyze server log files
Served as initial employee for an international bus search site, created technical proof of concept, built internal tools to manage bus companies and routes, connected over 100 external partners via inbound APIs and web scraping

Mar 2010 - Dec 2012

2 years 10 months

Software Developer

ingsoft GmbH

Ported the desktop application IngSoft InterWatt to a single-page web application using Backbone.js and a HTTP API
Implemented bi-directional data synchronization between internal and on-premise Silverlight systems
Created an Energy Savings Check app for a major Austrian energy company deployed to civilian customers in Silverlight
Ported parts of the desktop app from Win32 to WPF to improve user experience
Added ambitious features critical for the sales team to acquire large customers

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 Information Technology (13 years), Retail (6.5 years), Professional Services (5 years), Energy (4 years), Agriculture (3.5 years), and Tourism (3.5 years).

Information Technology

Retail

Professional Services

Energy

Agriculture

Tourism

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 (16 years), Product Development (13.5 years), Operations (3.5 years), Business Intelligence (3.5 years), Marketing (3.5 years), and Quality Assurance (3 years).

Information Technology

Product Development

Operations

Business Intelligence

Marketing

Quality Assurance

Summary

Full-stack development, to me, spans the breadth from an initial idea to a production rollout and ongoing support. While my focus is primarily on the technical design and implementation, I am capable of handling each aspect of the entire process – though specialist contributions are always welcome.

Beyond the planning and programming of the actual software, I bring my expertise to the entire development workflow: how to test the product (continually and before each release), how to align deployments, how to monitor the entire running system and handle second-level support for users.

Recently, I have been mostly focused on delivering mobile applications, though I am happy to apply my experience to any part of the software stack that will benefit from my contributions.

Skills

Flutter / Dart
Go
Grpc
Openapi
Postgresql
Redis
Aws
Google Cloud

Languages

German

Native

English

Advanced

French

Elementary

Education

Oct 2009 - Jun 2010

Friedrich-Alexander-Universität zu Erlangen-Nürnberg

Business Informatics · Erlangen, Germany

Oct 2000 - Jun 2009

Engelbert-Kaempfer-Gymnasium

General Qualification For University Entrance · Lemgo, Germany

Profile

Created

September 2025

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Timm based?

Timm is based in Munich, Germany.

What languages does Timm speak?

Timm speaks the following languages: German (Native), English (Advanced), French (Elementary).

How many years of experience does Timm have?

Timm has at least 16 years of experience. During this time, Timm has worked in at least 15 different roles and for 12 different companies. The average length of individual experience is 1 year and 1 month. Note that Timm may not have shared all experience and actually has more experience.

What roles would Timm be best suited for?

Based on recent experience, Timm would be well-suited for roles such as: Senior Backend-Framework Engineer, Senior Mobile App Developer, Energy supply contract sales & PV app, Senior Full-Stack Developer, Arabic language chat-bot app.

What is Timm's latest experience?

Timm's most recent position is Senior Backend-Framework Engineer at Serverpod AB.

What companies has Timm worked for in recent years?

In recent years, Timm has worked for Serverpod AB, TELESON Vertriebs GmbH, Mawdoo3, Buzz, and MySports GmbH & Magicline GmbH.

Which industries is Timm most experienced in?

Timm is most experienced in industries like Information Technology (IT), Retail, and Professional Services. Timm also has some experience in Energy, Tourism and Hospitality, and Agriculture.

Which business areas is Timm most experienced in?

Timm is most experienced in business areas like Information Technology (IT), Product Development, and Business Intelligence. Timm also has some experience in Marketing, Operations, and Sales.

Which industries has Timm worked in recently?

Timm has recently worked in industries like Information Technology (IT), Professional Services, and Agriculture.

Which business areas has Timm worked in recently?

Timm has recently worked in business areas like Information Technology (IT), Product Development, and Operations.

What is Timm's education?

Timm holds a Doctorate in Business Informatics from Friedrich-Alexander-Universität zu Erlangen-Nürnberg.

What is the availability of Timm?

Timm is immediately available full-time for suitable projects.

What is the rate of Timm?

Timm's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.