Jean-françois Greffier
Senior Front-End Developer at Blacknut
France
Summary
🤩
Rockstar🎓
Top SchoolJean-françois Greffier is a Senior Front-End Developer with 11 years of experience building web and mobile applications across telecommunications, startups, and product teams. He blends hands-on front-end engineering and technical leadership—driving legacy migrations, CI/CD improvements, and test-first practices to reduce dead code and code smells while enabling modern Angular development. An active open-source contributor and Playwright Ambassador, he has strengthened test automation for the widely used Playwright project and authored "Practical Playwright Test." His background also spans BLE mobile integrations (contributing device support to Gadgetbridge) and embedded device engineering, giving him a pragmatic edge when bridging hardware and front-end software. Based in France, he combines systems-level thinking with developer coaching and a proven track record of turning complex legacy stacks into maintainable, testable products.
10 years of coding experience
18 years of employment as a software developer
BTS Informatique Industrielle, BTS Informatique Industrielle at Lycée Maupertuis, Saint MaloBEP/CAP Electrotechnique, BEP/CAP Electrotechnique at Lycée Jean Jaurès, RennesNational Conservatory of Arts and Crafts
French, English, Chinese
Github Skills (24)
e2e-testing10
javascript10
testing10
e2e-test10
bluetooth-le10
android-development10
java10
javas10
btle10
playwright10
bluetooth-low-energy10
test-automation10
mib9
automation9
mi9
Programming languages (11)
Github contributions (5)
microsoft/playwright
Jul 2022 - Dec 2022
Playwright is a framework for Web Testing and Automation. It allows testing Chromium, Firefox and WebKit with a single API.
Role in this project:
QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:26 reviews, 12 commits, 25 PRs in 5 months
Contributions summary:Jean-françois's commits primarily focus on enhancing the testing capabilities of the Playwright framework. They added new test cases to cover inspector features, particularly keyboard shortcuts for pausing and stepping through code. The user's changes included modifying existing test files and adding new tests. They also implemented new tests to validate features like workers as a percentage of CPU, and `clear()` method.
web-testingchromiumtesting-toolsbrowser-automationfirefox
Freeyourgadget/Gadgetbridge
Jan 2019 - Mar 2019
We are on codeberg.org now! https://codeberg.org/Freeyourgadget/Gadgetbridge - Gadgetbridge - A free and cloudless replacement for your gadget vendors' closed source Android applications. Supports Pebble, Mi Band, Liveview, HPlus and more.
Role in this project:Mobile Developer (Android)
Mobile Developer (Android)Contributions:6 commits, 6 comments, 2 issues in 1 month
Contributions summary:Jean-françois primarily focused on adding support for the MiScale2 device to the Gadgetbridge application, evidenced by the creation of device coordinators, device-specific service implementations, and weight measurement functionalities. They developed features related to the Bluetooth Low Energy (BLE) communication with the scale, including data parsing and handling, as well as incorporating the device into the Gadgetbridge framework. The user also updated existing device support modules and made necessary modifications for compatibility and integration.
bandmi-bandandroid-applicationgadgetbridgehplus
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