Marcel Erz
Software Engineer at Meta
San Francisco, California, United States
Summary
🤩
Rockstar🎓
Top SchoolMarcel Erz is a seasoned software engineer in San Francisco with 12+ years building reliable web and infrastructure systems across startups and major platforms, currently at Meta. He has moved between hands-on engineering and people leadership—serving as an Engineering Manager before returning to an individual contributor role—so he balances delivery, mentoring, and technical ownership. Marcel’s contributions to open source include practical improvements to well-known tooling like yahoo/blink-diff (adding synchronous image comparison) and stability and promise-handling fixes in router.js, reflecting a focus on robustness and developer ergonomics. His background spans backend, full-stack, and system-level debugging from roles at Facebook, Yahoo, and Shipwire, where he advanced to principal-level responsibilities. Trained in German softwareengineering practice, he brings disciplined engineering habits and a knack for tightening APIs and tests that reduce real-world failure modes. Colleagues would describe him as a pragmatic problem-solver who prefers improving foundations over flashy rewrites.
12 years of coding experience
27 years of employment as a software developer
Fachinformatiker (Softwareengineering), Fachinformatiker (Softwareengineering) at Berufskolleg Platz der Republik für Technik und Medien Mönchengladbach
English, German
Github Skills (9)
javascript10
nodejs10
image-comparison10
testing10
configuration-management9
algorithms6
algorithm6
data-structures6
data-structure6
Programming languages (3)
Github contributions (5)
yahoo/blink-diff
Nov 2014 - Jul 2016
A lightweight image comparison tool.
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:102 commits, 8 PRs, 50 pushes in 1 year 8 months
Contributions summary:Marcel primarily contributed to the `yahoo/blink-diff` project by implementing a new feature, `runSync`, which provides synchronous image comparison. They also addressed a bug in `PNGImage.readImage`, ensuring correct scope usage. Furthermore, the user made improvements to the test descriptions, demonstrating a focus on code quality and usability. Finally, the user added initial configuration objects and structural recording scripts.
imagecomparisonimage-comparisoncomparison-toolsnapshot
tildeio/router.js
Jul 2014 - Jul 2014
Role in this project:Full-stack Developer
Full-stack DeveloperContributions:7 commits in 2 days
Contributions summary:Marcel primarily focused on improving the internal workings and stability of the router.js library. They addressed promise handling, optimized code through variable reuse and loop optimization, and fixed a critical bug related to the `reset()` function. Furthermore, they improved the API functionality to cover intermediate transition scenarios. Their work demonstrates a good understanding of the library's internal architecture.
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