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I've been a software developer and engineering leader for over two decades, blending deep technical expertise with a passion for AI innovation. I thrive on building strong engineering cultures, delivering high-impact products, and mentoring teams to achieve excellence. I remain actively engaged in the developer community as the proud maintainer of the open source Reek gem. I’ve spent most of my professional life in international startups with a strong focus on engineering culture and productivity, and I excel at building the right teams and scaling them up as the business grows.…I've been a software developer and engineering leader for over two decades, blending deep technical expertise with a passion for AI innovation. I thrive on building strong engineering cultures, delivering high-impact products, and mentoring teams to achieve excellence. I remain actively engaged in the developer community as the proud maintainer of the open source Reek gem. I’ve spent most of my professional life in international startups with a strong focus on engineering culture and productivity, and I excel at building the right teams and scaling them up as the business grows.

Timo Roessner

Fractional CTO, Web Developer, Data Scientist, +1

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I've been a software developer and engineering leader for over two decades, blending deep technical expertise with a passion for AI innovation. I thrive on building strong engineering cultures, delivering high-impact products, and mentoring teams to achieve excellence. I remain actively engaged in the developer community as the proud maintainer of the open source Reek gem. I’ve spent most of my professional life in international startups with a strong focus on engineering culture and productivity, and I excel at building the right teams and scaling them up as the business grows.…I've been a software developer and engineering leader for over two decades, blending deep technical expertise with a passion for AI innovation. I thrive on building strong engineering cultures, delivering high-impact products, and mentoring teams to achieve excellence. I remain actively engaged in the developer community as the proud maintainer of the open source Reek gem. I’ve spent most of my professional life in international startups with a strong focus on engineering culture and productivity, and I excel at building the right teams and scaling them up as the business grows.

Available to hire

I’ve been a software developer and engineering leader for over two decades, blending deep technical expertise with a passion for AI innovation. I thrive on building strong engineering cultures, delivering high-impact products, and mentoring teams to achieve excellence.

I remain actively engaged in the developer community as the proud maintainer of the open source Reek gem. I’ve spent most of my professional life in international startups with a strong focus on engineering culture and productivity, and I excel at building the right teams and scaling them up as the business grows.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Intermediate

Language

German

Advanced

English

Fluent

Work Experience

Fractional CTO / Freelance Developer at Toptal

March 1, 2020 - December 1, 2022

Managed product-related development teams (around 150 developers, 25 teams).

Director of Engineering at TopTal

October 1, 2018 - March 1, 2021

Led engineering teams and built new analytics products on top of large data assets.

Director of Platform Engineering at Planet

October 1, 2016 - December 1, 2017

Led a team of sustainability experts; supported food manufacturers, agricultural traders, financial institutions, NGOs and government agencies to understand land conversion risks and reduction opportunities using Python and Google Cloud.

CTO at Adastra

January 1, 2023 - April 1, 2025

Interim CTO-level leadership; drove AI strategy, coaching, technical vision and rapid AI feature development; led teams building AI-powered solutions.

Fractional CTO at Turf Coach

May 1, 2025 - Present

Sports tech startup delivering real-time data analytics on football pitch conditions; combined AI, sensors and software to deliver insights; led AI strategy and scaling the engineering organization.