Tobias Pfeiffer
Back End Developer at Together AI
Berlin, Germany
Summary
🤩
Rockstar🎓
Top SchoolTobias Pfeiffer is a seasoned Back End Developer with 15 years of experience building reliable, fast, and maintainable systems, currently focused on payments and backend reliability at Together AI. He blends deep Ruby and Elixir expertise—sharpened at Shopify and through sustained open-source contributions to projects like Elixir, SimpleCov and Wallaby—with pragmatic engineering leadership in distributed teams. Tobias excels at turning fragile processes into robust pipelines, having introduced background job systems, payment automations (PAIN XML, direct debit) and company-wide RFC and branching improvements. A proven mentor and teacher, he regularly onboarded non-Elixir engineers via training camps and structured mentoring. Beyond production code he contributes UX and tooling improvements across well-known OSS projects, reflecting a curiosity for both developer experience and low-level language/library design.
15 years of coding experience
11 years of employment as a software developer
Master's Degree IT-Systems Engineering, Master's Degree IT-Systems Engineering at Hasso Plattner InstituteSoftware Engineering, Software Engineering at Blekinge Institute of Technology
German, English, Swedish, French
Github Skills (46)
crystal-lang10
elixir10
testing10
css10
cucumber10
enumerable10
test-framework10
ui-design10
editor10
ruby10
erb10
uid10
github-pages10
front-end-development10
html10
Programming languages (19)
Github contributions (5)
shoes/shoes4
Jun 2012 - Aug 2019
Shoes 4 : the next version of Shoes
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:1278 commits, 248 PRs, 264 pushes in 7 years 3 months
Contributions summary:Tobias was actively involved in the development of the Shoes 4 project, focusing on the implementation of GUI elements and the underlying Ruby/JRuby framework. Their contributions included adding and modifying various features, such as implementing simplecov for testing and fixing bugs related to text rendering and positioning within the GUI. The user also contributed to the user interface by developing the integration of the framework, and also implementing methods for rendering text strings and the display.
mac-osxwindowsswtnext-versionlinux
simplecov-ruby/simplecov
Nov 2016 - Jan 2022
Code coverage for Ruby with a powerful configuration library and automatic merging of coverage across test suites
Role in this project:Backend Developer
Backend DeveloperContributions:24 releases, 54 reviews, 386 commits in 5 years 3 months
Contributions summary:Tobias primarily contributed to the SimpleCov code coverage library for Ruby, focusing on core functionality and bug fixes. Their contributions included modifications to the versioning, result handling, and testing aspects of the library. Furthermore, they implemented improvements related to branch coverage, ensuring accurate reporting and handling of various code structures.
railstestingsuitesrubymerging
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