whoami

Jannis Jahr — Backend & Fullstack Developer based in Berlin, Germany. Master’s degree in media computer science, mostly writing Python and Kotlin against PostgreSQL, running on Kubernetes. Background in connected devices and building automation.

cat ~/work/zeit.log

DIE ZEIT — Software Developer

Berlin, Germany · July 2024 – present

Backend services for one of Germany’s largest news sites — comments, bookmarks and paywall delivery.

  • Built a real-time moderation tool on Server-Sent Events, PostgreSQL and PostgREST.
  • Python backends, tested with pytest. Some frontend work in React and Svelte.
  • Instrumented services with OpenTelemetry, tracing in Honeycomb, dashboards in Grafana.
  • Everything on Kubernetes, infrastructure as code with Terraform and Terragrunt.
cat ~/projects/starklicht.log

Starklicht — my own project

starklicht.net · released under Starklicht UG

A controllable lamp for film production. STM32 firmware plus companion apps in native Android, native iOS and Flutter. Now open source under GPL-3.0.

→ starklicht.net

cat ~/work/history.log

Career log

Freelance — Full-Stack Developer Berlin, Germany · June 2022 – July 2026 Built Starklicht as my own product. Kieback & Peter remained a client throughout, continuing work on their building automation platform.

Kieback & Peter GmbH & Co. KG — Full-Stack Developer Berlin, Germany · May 2021 – May 2022

  • Led development of an internal building automation platform, used by more than 300 people in the company.
  • Backend in Kotlin and Spring Boot on PostgreSQL, migrations with Flyway.
  • Frontend in Vue.js and TypeScript, Azure infrastructure set up with Terraform.
  • Mentored a junior developer.

Volkswagen AG Digital:Lab — Full-Stack Developer (Working Student) Berlin, Germany · November 2019 – April 2020 GDPR compliance features for Volkswagen IdentityKit. Spring Boot, React, AWS.

byte für byte — Shopware Developer (Working Student) Bremen, Germany · April 2017 – September 2017 Shopware plugins in PHP and Smarty with MySQL.

CTS EVENTIM AG & Co. KGaA — Frontend Web Developer (Intern) Bremen, Germany · September 2016 – February 2017

cat ~/education.log

Education

M.Sc. Media Computer Science — HTW Berlin (International Programme) Berlin, Germany · April 2018 – February 2021 Focus on user-centered web technologies, real-time systems, computer vision and AI. Thesis on a platform that recognises the motion of several people and transfers it to 3D animation software.

B.Sc. Media Computer Science — Hochschule Bremen (International Programme) Bremen, Germany · September 2013 – August 2017 Tutor for maths and media computer science, 2014–2015.

Exchange Semester, Computer Science — UFRGS Porto Alegre, Brazil · July 2015 – December 2015 Studied Ciência da Computação in Portuguese.

cat ~/skills.yaml

Stack

  • Programming — Python, Kotlin, Java, Rust, TypeScript, SQL
  • Backend — FastAPI, Spring Boot, PostgreSQL, PostgREST, REST APIs
  • Infrastructure — Kubernetes, Docker, Terraform, Azure, GCP, AWS, CI/CD
  • Observability — OpenTelemetry, Honeycomb, Grafana
  • Frontend — Vue.js, React, Svelte
  • Embedded — STM32, C, microcontrollers
  • Languages — German (native), English (fluent), Portuguese (basic conversation)
cat ~/interests.txt

Off duty

Electronics, 3D printing and microcontrollers — I run Home Assistant at home and I’m currently building a card sorter for trading card games with image recognition. Otherwise: hiking, snowboarding, motorcycles and bicycles, outdoors whenever possible.

contact --info

Get in touch