Robert Schäfer

Full Stack Developer

Official CV

For the official PDF version of this CV, use the links below.

Website
https://roschaefer.de/en/
Direct PDF
https://roschaefer.de/en/robert-schaefer-resume.en.pdf
Robert Schäfer
  • EN
  • DE
Switch color theme
  • Projects
  • Experience
  • Contact

Software quality made visible.

Freelance full stack developer working remotely across web applications, product engineering, and infrastructure, with additional investment in open source. Focus areas include maintainable software, strong test coverage, and modernizing fragile systems by simplifying delivery and operations while strengthening quality through reliable collaboration, code reviews, pair programming, and technical mentoring.

  • Browse projects
  • Get in touch

Robert Schäfer

Full Stack Developer

Portrait of Robert Schäfer
Based in
Cologne, NRW
Languages
German . English . Spanish
  • LinkedIn
  • Github
  • YouTube
  • Mastodon
  • Download CV (PDF) English version, direct file download
  • Download ATS CV Text-first PDF for applicant tracking systems
Download CV as JSON Resume

Tech experience

Project-backed technology signals

Each technology combines three signals: time spent with it, how many projects it appeared in, and how recently it was part of shipped work.

TechnologyExperienceProjectsLast used
TypeScript5¾ years10 · Remote observatory, AI interview platform, roschaefer.de, Founder network, Newsroom dialog, Auto parts price comparison, SvelteKit relaunch, Booking system for course providers, Booking system for continuing education providers, Booking website for a holiday apartment
10 projects
  • Remote observatory
  • AI interview platform
  • roschaefer.de
  • Founder network
  • Newsroom dialog
  • Auto parts price comparison
  • SvelteKit relaunch
  • Booking system for course providers
  • Booking system for continuing education providers
  • Booking website for a holiday apartment
Current
Docker7½ years6 · Remote observatory, Founder network, Newsroom dialog, Auto parts price comparison, FOSS social network, Custom CMS platform
6 projects
  • Remote observatory
  • Founder network
  • Newsroom dialog
  • Auto parts price comparison
  • FOSS social network
  • Custom CMS platform
Current
Vue6½ years6 · Remote observatory, Founder network, Auto parts price comparison, Booking system for course providers, Systems-Development and Framework, FOSS social network
6 projects
  • Remote observatory
  • Founder network
  • Auto parts price comparison
  • Booking system for course providers
  • Systems-Development and Framework
  • FOSS social network
Current
Tailwind4½ years7 · Remote observatory, AI interview platform, roschaefer.de, Auto parts price comparison, Booking system for continuing education providers, Booking website for a holiday apartment, Systems-Development and Framework
7 projects
  • Remote observatory
  • AI interview platform
  • roschaefer.de
  • Auto parts price comparison
  • Booking system for continuing education providers
  • Booking website for a holiday apartment
  • Systems-Development and Framework
Current
Nuxt5 years4 · Remote observatory, Booking system for course providers, Systems-Development and Framework, FOSS social network
4 projects
  • Remote observatory
  • Booking system for course providers
  • Systems-Development and Framework
  • FOSS social network
Current
Netlify3½ years6 · AI interview platform, roschaefer.de, SvelteKit relaunch, Booking system for course providers, Booking system for continuing education providers, Booking website for a holiday apartment
6 projects
  • AI interview platform
  • roschaefer.de
  • SvelteKit relaunch
  • Booking system for course providers
  • Booking system for continuing education providers
  • Booking website for a holiday apartment
Current
PostgreSQL4¾ years4 · AI interview platform, Founder network, Rundfunk mitbestimmen, Web application for sports associations
4 projects
  • AI interview platform
  • Founder network
  • Rundfunk mitbestimmen
  • Web application for sports associations
Current
Sentry5¾ years2 · AI interview platform, Newsroom dialog
2 projects
  • AI interview platform
  • Newsroom dialog
Current
Cucumber2¾ years6 · Remote observatory, hledger-document-check, hledger-elster, Bee sensor stories, Dairy cow sensor stories, Web application for sports associations
6 projects
  • Remote observatory
  • hledger-document-check
  • hledger-elster
  • Bee sensor stories
  • Dairy cow sensor stories
  • Web application for sports associations
Current
Svelte2¾ years5 · AI interview platform, roschaefer.de, SvelteKit relaunch, Booking system for continuing education providers, Booking website for a holiday apartment
5 projects
  • AI interview platform
  • roschaefer.de
  • SvelteKit relaunch
  • Booking system for continuing education providers
  • Booking website for a holiday apartment
Current
SvelteKit2¾ years5 · AI interview platform, roschaefer.de, SvelteKit relaunch, Booking system for continuing education providers, Booking website for a holiday apartment
5 projects
  • AI interview platform
  • roschaefer.de
  • SvelteKit relaunch
  • Booking system for continuing education providers
  • Booking website for a holiday apartment
Current
Serverless2 years2 · AI interview platform, SvelteKit relaunch
2 projects
  • AI interview platform
  • SvelteKit relaunch
Current
Terraform1½ years2 · Remote observatory, Founder network
2 projects
  • Remote observatory
  • Founder network
Current
Playwright6 months3 · Remote observatory, AI interview platform, roschaefer.de
3 projects
  • Remote observatory
  • AI interview platform
  • roschaefer.de
Current
hledger6 months2 · hledger-document-check, hledger-elster
2 projects
  • hledger-document-check
  • hledger-elster
Current
Rust6 months2 · hledger-document-check, hledger-elster
2 projects
  • hledger-document-check
  • hledger-elster
Current
Vitest6 months2 · AI interview platform, roschaefer.de
2 projects
  • AI interview platform
  • roschaefer.de
Current
AWS6 months1 · Remote observatory
1 project
  • Remote observatory
Current
Better Auth6 months1 · AI interview platform
1 project
  • AI interview platform
Current
Drizzle ORM6 months1 · AI interview platform
1 project
  • AI interview platform
Current
ElevenLabs6 months1 · AI interview platform
1 project
  • AI interview platform
Current
Fly.io6 months1 · Remote observatory
1 project
  • Remote observatory
Current
Infisical6 months1 · AI interview platform
1 project
  • AI interview platform
Current
Neon DB6 months1 · AI interview platform
1 project
  • AI interview platform
Current
NINA6 months1 · Remote observatory
1 project
  • Remote observatory
Current
Paraglide6 months1 · roschaefer.de
1 project
  • roschaefer.de
Current
Tailscale6 months1 · Remote observatory
1 project
  • Remote observatory
Current
Typst6 months1 · roschaefer.de
1 project
  • roschaefer.de
Current
Apollo GraphQL5¾ years4 · Founder network, Auto parts price comparison, Systems-Development and Framework, FOSS social network
4 projects
  • Founder network
  • Auto parts price comparison
  • Systems-Development and Framework
  • FOSS social network
Jun 2025
Jest5 years3 · Founder network, Auto parts price comparison, FOSS social network
3 projects
  • Founder network
  • Auto parts price comparison
  • FOSS social network
Jun 2025
Kubernetes2½ years2 · Founder network, FOSS social network
2 projects
  • Founder network
  • FOSS social network
Jun 2025
Vuetify2½ years2 · Founder network, Systems-Development and Framework
2 projects
  • Founder network
  • Systems-Development and Framework
Jun 2025
Authentik1 year1 · Founder network
1 project
  • Founder network
Jun 2025
Helm1 year1 · Founder network
1 project
  • Founder network
Jun 2025
Hetzner1 year1 · Founder network
1 project
  • Founder network
Jun 2025
Vike1 year1 · Founder network
1 project
  • Founder network
Jun 2025
Ruby9¼ years5 · Newsroom dialog, Bee sensor stories, Rubies in the woods, Dairy cow sensor stories, Web application for sports associations
5 projects
  • Newsroom dialog
  • Bee sensor stories
  • Rubies in the woods
  • Dairy cow sensor stories
  • Web application for sports associations
Apr 2025
Ruby on Rails8¾ years5 · Newsroom dialog, Bee sensor stories, Rundfunk mitbestimmen, Dairy cow sensor stories, Web application for sports associations
5 projects
  • Newsroom dialog
  • Bee sensor stories
  • Rundfunk mitbestimmen
  • Dairy cow sensor stories
  • Web application for sports associations
Apr 2025
RSpec7½ years4 · Newsroom dialog, Bee sensor stories, Dairy cow sensor stories, Web application for sports associations
4 projects
  • Newsroom dialog
  • Bee sensor stories
  • Dairy cow sensor stories
  • Web application for sports associations
Apr 2025
Digital Ocean6½ years2 · Newsroom dialog, FOSS social network
2 projects
  • Newsroom dialog
  • FOSS social network
Apr 2025
Ansible5¼ years1 · Newsroom dialog
1 project
  • Newsroom dialog
Apr 2025
Postmark5¼ years1 · Newsroom dialog
1 project
  • Newsroom dialog
Apr 2025
Stimulus5¼ years1 · Newsroom dialog
1 project
  • Newsroom dialog
Apr 2025
Auth05 years2 · Auto parts price comparison, Rundfunk mitbestimmen
2 projects
  • Auto parts price comparison
  • Rundfunk mitbestimmen
Sep 2023
Google Cloud2¼ years1 · Auto parts price comparison
1 project
  • Auto parts price comparison
Sep 2023
Hasura2¼ years1 · Auto parts price comparison
1 project
  • Auto parts price comparison
Sep 2023
Testing-Library2¼ years1 · Auto parts price comparison
1 project
  • Auto parts price comparison
Sep 2023
Vercel2¼ years1 · Auto parts price comparison
1 project
  • Auto parts price comparison
Sep 2023
HyGraph3 years2 · SvelteKit relaunch, Booking system for course providers
2 projects
  • SvelteKit relaunch
  • Booking system for course providers
Jun 2023
JavaScript3¾ years4 · Systems-Development and Framework, FOSS social network, Smart bathroom mirror, Protothon
4 projects
  • Systems-Development and Framework
  • FOSS social network
  • Smart bathroom mirror
  • Protothon
Mar 2021
Neo4J2½ years2 · Systems-Development and Framework, FOSS social network
2 projects
  • Systems-Development and Framework
  • FOSS social network
Mar 2021
Cypress1½ years1 · FOSS social network
1 project
  • FOSS social network
Apr 2020
Storybook1½ years1 · FOSS social network
1 project
  • FOSS social network
Apr 2020
Ember2¾ years2 · Rundfunk mitbestimmen, Smart shopping cart
2 projects
  • Rundfunk mitbestimmen
  • Smart shopping cart
Mar 2019
D32¾ years1 · Rundfunk mitbestimmen
1 project
  • Rundfunk mitbestimmen
Mar 2019
Highcharts2¾ years1 · Rundfunk mitbestimmen
1 project
  • Rundfunk mitbestimmen
Mar 2019
Uberspace2¾ years1 · Rundfunk mitbestimmen
1 project
  • Rundfunk mitbestimmen
Mar 2019
PHP3 months1 · Custom CMS platform
1 project
  • Custom CMS platform
Jun 2018
Wordpress3 months1 · Custom CMS platform
1 project
  • Custom CMS platform
Jun 2018
Python2 months2 · Smart bathroom mirror, Smart shopping cart
2 projects
  • Smart bathroom mirror
  • Smart shopping cart
Jan 2018
MQTT1 month1 · Smart bathroom mirror
1 project
  • Smart bathroom mirror
Jan 2018
Java8 months1 · Enterprise programming models for in-memory databases
1 project
  • Enterprise programming models for in-memory databases
Aug 2012

Selected work

Project experience

Full Stack Developer

Bo***bH

Remote observatory

2026-03-25 - present

With this platform for remotely controlling telescopes through the astrophotography software NINA, deep-sky imaging gets accessible without owning expensive hardware or the expertise to operate it. Users select an astronomical target and book observation time; the application sends imaging sequences to NINA via Tailscale, which executes them overnight and delivers the results. The core challenge is turning a Windows-only, inherently interactive application into a fully autonomous pipeline.

  • TypeScript
  • Nuxt
  • Vue
  • Fly.io
  • Docker
  • AWS
  • Terraform
  • Playwright
  • Cucumber
  • Tailwind
  • NINA
  • Tailscale

Full Stack Developer

ta***bH

AI interview platform

2026-03-23 - present

This SvelteKit application for AI-assisted interviews and editorial publishing replaces brittle infrastructure spread across Airtable, Voiceflow, and additional custom services with a single serverless application. Using the built-in workflows of ElevenLabs AI Agents significantly reduces maintenance overhead and complexity while improving the phone agent's response time by several seconds, which is crucial for a good user experience.

  • TypeScript
  • Svelte
  • SvelteKit
  • Tailwind
  • Better Auth
  • Drizzle ORM
  • Neon DB
  • PostgreSQL
  • Playwright
  • Vitest
  • Netlify
  • Sentry
  • Serverless
  • Infisical
  • ElevenLabs

Full Stack Developer

***

Founder network

2024-06-21 - 2025-06-09

For this free and open-source social platform for entrepreneurs, the delivery and infrastructure architecture was fundamentally reworked after deployments had previously been performed manually via a remote desktop on the target server, regularly causing downtime. Moving the project to a self-managed Kubernetes setup on Hetzner with Terraform gave every developer production-like test environments for their own branches while keeping operating costs extremely low at under 20 euros per month.

  • TypeScript
  • Docker
  • Vue
  • Vike
  • Vuetify
  • Jest
  • Authentik
  • Apollo GraphQL
  • Terraform
  • Helm
  • Kubernetes
  • Hetzner
  • PostgreSQL

Full Stack Developer

au***bH

Auto parts price comparison

2021-06-30 - 2023-09-01

For this software for the automotive aftermarket that helps repair shops compare prices across wholesalers, an Electron desktop application was migrated to a cloud-based platform on Google Cloud, Auth0, and Hasura. This significantly improved software quality and increased the number of connected wholesalers from 3 to 240.

  • TypeScript
  • Docker
  • Vue
  • Tailwind
  • Jest
  • Testing-Library
  • Auth0
  • Apollo GraphQL
  • Hasura
  • Google Cloud
  • Vercel

Full Stack Developer

ta***bH

Newsroom dialog

2020-03-30 - 2025-04-16

For this platform for audience engagement and crowd-based reporting in journalism, the Ruby on Rails application integrates messengers such as WhatsApp, Telegram, Signal, Threema, and email, allowing editorial teams to reach people through channels they already use. Its core differentiator is a direct 1:1 conversation between journalists and their audience, turning a newsroom's own community into a valuable asset for reporting and research.

  • Ruby
  • TypeScript
  • Ruby on Rails
  • RSpec
  • Stimulus
  • Docker
  • Ansible
  • Digital Ocean
  • Sentry
  • Postmark

Technical Lead

bu***V.

FOSS social network

2018-11-30 - 2020-04-30

Technical Lead work on product architecture, GraphQL APIs, production use of Neo4J, and Kubernetes-based operations for a community-built open-source social network that offers communities a privacy-friendly alternative to large platforms. The project grew to around 80 code contributors on GitHub; newcomers were onboarded through GitHub, Discord, and online pair programming, mentored directly, and most contributions were reviewed. Neo4J ran in production as the primary database to model the network's social graph directly.

  • JavaScript
  • Jest
  • Vue
  • Nuxt
  • Storybook
  • Cypress
  • Apollo GraphQL
  • Neo4J
  • Docker
  • Digital Ocean
  • Kubernetes

University Lecturer

Hochschule für Technik und Wirtschaft Berlin

Systems-Development and Framework

2019-10-31 - 2021-03-31

Owned a master's course on full stack development with around 40 students, including curriculum, teaching, and grading. Topics included functional programming, advanced Git, test-driven development, and code reviews on GitHub. All lectures are publicly available on YouTube.

  • JavaScript
  • Vue
  • Apollo GraphQL
  • Neo4J
  • Nuxt
  • Vuetify
  • Tailwind

Design and Development

Robert Schäfer

roschaefer.de

2026-03-16 - present

Personal portfolio website and print-optimized resume built from a shared content source. The project combines a bilingual SvelteKit frontend, PDF generation with Typst, and standards-compliant `resume.json` into an accessible, privacy-conscious experience for web and print.

  • TypeScript
  • Svelte
  • SvelteKit
  • Tailwind
  • Paraglide
  • Typst
  • Vitest
  • Playwright
  • Netlify

Development

Robert Schäfer

hledger-document-check

2026-03-19 - present

A Plain Text Accounting command-line tool for checking documents with hledger. It reconciles transactions that require documentation with files on disk, detects missing or unbooked documents, checks amount plausibility, and generates an enriched journal for Fava's document view.

  • Rust
  • hledger
  • Cucumber

Development

Robert Schäfer

hledger-elster

2026-03-19 - present

A Plain Text Accounting command-line tool for hledger that automates German tax filing. It reads transactions from the journal and generates traceable exports for the corresponding forms on ELSTER.de. The exports are available in CSV and XLSX format and include derivations that tax authorities can audit.

  • Rust
  • hledger
  • Cucumber

Full Stack Developer

Jo***er

Booking website for a holiday apartment

2022-01-28 - 2022-08-09

Built a booking website with calendar integration for a holiday apartment on Norderney. Day-by-day availability is maintained in Google Calendar and synchronized to the site via Google APIs.

  • TypeScript
  • Netlify
  • Svelte
  • SvelteKit
  • Tailwind

Full Stack Developer

Jo***er

SvelteKit relaunch

2021-12-09 - 2023-06-28

Rebuilt a retail client's website with SvelteKit and Hygraph and deployed it statically on Netlify. Server-side logic runs in serverless functions, and content is loaded from the headless CMS via GraphQL. The relaunch improved performance, SEO, and maintainability.

  • TypeScript
  • Svelte
  • SvelteKit
  • HyGraph
  • Netlify
  • Serverless

Full Stack Developer

Jo***er

Booking system for continuing education providers

2021-05-12 - 2022-12-10

Built a custom booking system for a continuing education provider. The solution includes email confirmations, waiting lists, and an implementation based on SvelteKit with Hygraph as the headless CMS.

  • TypeScript
  • Netlify
  • Svelte
  • SvelteKit
  • Tailwind

Full Stack Developer

Jo***er

Booking system for course providers

2020-08-11 - 2023-05-02

Built a custom booking system for a course provider's sewing classes and integrated it into their website. Courses for adults, teens, and children can be managed online, including registration and waiting lists.

  • TypeScript
  • Netlify
  • Vue
  • Nuxt
  • HyGraph

Full Stack Developer

ta***bH

Bee sensor stories

2019-03-31 - 2019-05-31

Building on an earlier journalistic sensor-data project, the platform was reused and extended for a new format. Reports were generated automatically from sensor data collected from three beehives. The project was nominated for the Grimme Online Award and won the German Reporter Award.

  • Ruby
  • Ruby on Rails
  • RSpec
  • Cucumber

Full Stack Developer

So***AG

Custom CMS platform

2018-04-30 - 2018-06-30

Custom CMS development for the company website with a focus on maintainability and search engine optimization.

  • Wordpress
  • PHP
  • Docker

IoT Developer

ta***bH

Smart bathroom mirror

2018-01-01 - 2018-01-31

Rapid IoT prototype of a smart bathroom mirror and cabinet built with Raspberry Pis, Arduinos, and MQTT.

  • Python
  • JavaScript
  • MQTT

IoT Developer

ta***bH

Smart shopping cart

2017-06-01 - 2017-06-30

Rapid IoT prototype of a smart shopping cart.

  • Ember
  • Python

Founder

Rundfunk mitbestimmen e.V.

Rundfunk mitbestimmen

2016-08-31 - 2019-03-31

"Rundfunk mitbestimmen" is a civic tech project that lets people symbolically influence how public broadcasting fees are allocated. Users can assign their contributions to individual programs. The project was covered by Zeit Online, Netzpolitik.org, Deutschlandfunk, and RBB.

  • Ember
  • Ruby on Rails
  • Auth0
  • D3
  • Highcharts
  • Uberspace
  • PostgreSQL
Press coverage (4)

Full Stack Developer

ta***bH

Dairy cow sensor stories

2016-05-31 - 2017-10-31

For WDR and Spiegel Online, a journalistic format generated reports automatically from sensor data collected from three dairy cows. The project received broad media attention with more than 63 reports and features.

  • Ruby on Rails
  • Ruby
  • RSpec
  • Cucumber
Press coverage (1)

Programming Mentor

MIZ Babelsberg

Rubies in the woods

2015-09-30 - 2018-11-30

Mentored a beginner-friendly programming group through weekly sessions focused on diversity and low-barrier access to learning how to code.

  • Ruby

Hackathon Coach

MIZ Babelsberg

Protothon

2015-08-31 - 2016-09-30

  • JavaScript

Hackathon Coach

MIZ Babelsberg

#ursuppe

2015-08-01 - 2015-08-31

Coached the team behind #ursuppe, an IoT prototype that automatically generated a live journalism report from a biological experiment tracking brine shrimp. Winner of the MIZ Formatfestival 2015.

Research Intern

***

Automated Risk Analysis in Supply Chains

2013-10-01 - 2013-11-30

Built a tool for automated risk analysis in supply chains, working with an existing legacy codebase.

Full Stack Developer

OX***AG

Web application for sports associations

2013-04-01 - 2013-09-30

First developer to introduce an automated test environment for this web application for officials, referees, and coaches.

  • Ruby
  • Ruby on Rails
  • RSpec
  • Cucumber
  • PostgreSQL

Researcher

Hasso Plattner Institute

Enterprise programming models for in-memory databases

2012-01-31 - 2012-08-31

Implementation of a business process and web application as specified by SAP as a use case for the HANA in-memory database.

  • Java

Speaking

Talks and teaching

Talks and teaching sessions are linked directly for quick access.

  • Vue.js Berlin Meetup

    Find open-source contributors in online learner communities

    2020-01-14

  • Neo4J Online Meetup

    Using Neo4J and GraphQL to build Human Connection

    2019-06-20

  • 35th Chaos Communication Congress

    Find open-source contributors in online learner communities

    2018-12-30

  • Ember.js Meetup Berlin

    Story-Trolley: Ember meets the IoT

    2018-01-19

  • 34th Chaos Communication Congress

    Rundfunk mitbestimmen

    2017-12-30

  • Z2X Festival - Die Zeit

    How to enjoy paying for public broadcasting

    2017-09-04

Education

Academic background

Selected degrees from the resume, matching the curated PDF version.

  1. 2014 - 2018

    Master of Science

    IT-Systems Engineering

    Hasso Plattner Institute

    Grade
    1.6
  2. 2009 - 2012

    Bachelor of Science

    IT-Systems Engineering

    Hasso Plattner Institute

    Grade
    1.7

Recognition

Awards and nominations

Award nominations and prizes for journalism and hackathon projects I contributed to.

  1. 2020

    Grimme Online Award (nominated)

    Grimme-Institut

    Bee sensor stories

  2. 2019

    German Reporter Award 2019

    Reporter-Forum e. V.

    Bee sensor stories

  3. 2017

    German Reporter Award 2017 (nominated)

    Reporter-Forum e. V.

    Dairy cow sensor stories

  4. 2015

    Winner of MIZ Formatfestival 2015

    MIZ Babelsberg

    #ursuppe

In the media

Press coverage

Press coverage of journalism and civic tech projects I contributed to — each item links back to the project it covers.

  1. 2016

    Rundfunk mitbestimmen

    Rundfunk mitbestimmen e.V.

    • Zeit Online
    • Netzpolitik.org
    • Deutschlandfunk
    • RBB
  2. 2016

    Dairy cow sensor stories

    ta***bH

    • Spiegel Online

Contact

  • Email: hello@roschaefer.de
  • Signal: public Signal link

Remote-friendly full stack development, open source collaboration, and technical speaking.

  • LinkedIn
  • Github
  • YouTube
  • Twitter
  • Mastodon
  • CodeMentor
  • Imprint
  • Privacy