It's not just Not Invented Here Syndrome. Some technologies like CSS simply don't scale if you're building some of the largest websites on the planet with thousands of engineers committing to the same code base every day. StyleX is Meta's open-source solution for CSS at scale and allows atomic styling of components while deduplicating definitions for bundle size and exposing a delightfully simple API for developers.

Tune in to learn from Melissa, one of the StyleX maintainers how Open Source has acted as a force multiplier for the project, how interacting with other large companies adopting StyleX has been, and much more!

Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Instagram (https://instagram.com/metatechpod) and don't forget to follow our host Pascal (https://mastodon.social/@passy, https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/.

Links

• How AI Is Transforming the Adoption of Secure-by-Default Mobile Frameworks: https://engineering.fb.com/2025/12/15/android/how-ai-transforming-secure-by-default-mobile-frameworks-adoption/

• StyleX: A Styling Library for CSS at Scale:
  https://engineering.fb.com/2025/11/11/web/stylex-a-styling-library-for-css-at-scale/

• StyleX: https://stylexjs.com

• MTP 67: Measuring Developer Productivity with Diff Authoring Time: https://pca.st/pt4p4tv5

Timestamps

• Intro and news 0:06

• Introduction Melissa 1:47

• Why did we build our own styling system? 4:07

• StyleX API 5:36

• cx vs StyleX 7:37

• Component styling and priorities 10:38

• How StyleX evolved in the past seven years 15:20

• Community influence 19:33

• Open Source 24:07

• Challenges of OSS 27:02

• Managed breaking changes in OSS 29:48

• Measuring success for StyleX 32:04

• Packaging challenges 34:34

• StyleX competition 38:42

• Creating the StyleX roadmap 40:24

• Outro 43:15

You've likely heard of Meta Ray-Ban Display by now — but what's it actually like to work on it? In this episode, Pascal talks to Kenan and Emanuel about the exciting features of Meta's First-Gen Display Glasses and Neural Wristband, the engineering and product challenges they encountered during development, and their vision for future generations of these devices.

Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Instagram (https://instagram.com/metatechpod) and don't forget to follow our host Pascal (https://mastodon.social/@passy, https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/.

Links

• Pyrefly Beta: https://pyrefly.org/blog/pyrefly-beta/

• Pyrefly and Pydantic: https://pyrefly.org/blog/pyrefly-pydantic/

• Meta Ray-Ban Display: https://www.meta.com/gb/ai-glasses/meta-ray-ban-display/

Timestamps

• Intro 0:06

• Introduction Kenan 1:35

• Introduction Emanuel 5:03

• Roles and responsibilities 8:07

• What is Meta Ray-Ban Display? 11:13

• Memorable challenges: Clasps 15:52

• Memorable challenges: Display 19:24

• Celebrating incremental wins 23:51

• The feedback cycle in hardware engineering 26:29

• Open culture and dogfooding 31:39

• One-way doors 32:44

• Striving for quality and polish in fast-moving environments 36:25

• UI principles for AI glasses 40:15

• Future Plans 44:04

• Outro 46:53

• Blooper 47:49

In this episode, Pascal talks to Dharmesh J. (DJ) and Lisa about the vision for the open, scalable future of networking hardware for AI and to break down Meta's big announcements from the 2025 Open Compute Project (OCP) Summit. We dive into the OCP ecosystem, explore how AI is used to enhance our carbon modeling, and share our progress toward achieving Net Zero emissions across all scopes by 2030.

Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Instagram (https://instagram.com/metatechpod) and don't forget to follow our host Pascal (https://mastodon.social/@passy, https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/.

Links

• OCP: https://www.opencompute.org/

• OCP Summit 2025: https://engineering.fb.com/2025/10/13/data-infrastructure/ocp-summit-2025-the-open-future-of-networking-hardware-for-ai/

• How Meta Is Leveraging AI To Improve the Quality of Scope 3 Emission Estimates for IT Hardware: https://engineering.fb.com/2025/10/14/data-center-engineering/how-meta-is-leveraging-ai-to-improve-the-quality-of-scope-3-emission-estimates-for-it-hardware/

Timestamps

• Intro 0:06

• Introduction Lisa 1:49

• Introduction DJ 3:16

• What is OCP? 4:04

• OCP's scale 5:24

• Open vs closed hardware ecosystems 9:26

• Examples of OCP projects 11:33

• Sustainability in OCP 14:08

• How did you get into OCP? 15:59

• Marrying infrastructure growth with sustainability 19:05

• Emissions scopes and tracking 25:07

• Measuring scope 3 26:06

• What components embed the most carbon? 30:47

• DFE vs DFS 32:34

• Hardware reuse 33:39

• Outro 37:48