Brought to you by Meta. In addition to remaining active in the open source community and conference circuit, this podcast offers another channel that allows us to highlight the technical work of our engineers who will discuss everything from low-level frameworks to end-user features. Throughout the podcast, Meta engineer Pascal Hartig (@passy) will interview developers in the company.

48: A 94% reduction for basic video compute time on Instagram

January 25, 2023 37:22 18.42 MB Downloads: 0

Ryan and his team found a quick way of reducing the compute resources spent on encoding videos for Instagram by 94%, but that was actually the easy part. Tune in to learn what the fix was and how you roll out changes that can affect the user experience of billions of users. Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy and https://mastodon.social/@passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Reducing Instagram’s basic video compute time by 94 percent - Meta Engineering Blog: https://engineering.fb.com/2022/11/04/video-engineering/instagram-video-processing-encoding-reduction/  The Diff: https://thediffpodcast.com/ Unix Signals in Production - Dangers and Pitfalls: https://developers.facebook.com/blog/post/2022/09/27/signals-in-prod-dangers-and-pitfalls/ Introducing Velox: An open source unified execution engine - https://engineering.fb.com/2022/08/31/open-source/velox/ Timestamps: Intro 0:06 Intro Ryan 1:40 Transcoding Video at Instagram 2:52 Codecs and Tradeoffs 5:33 Client Support 7:13 Where did the compute go? 9:15 ABR 10:59 Progressive/Non-ABR Encodings 12:31 Saving Encoding Time 13:10 Testing the Changes 17:39 Results 26:43 Popularity Predictions 28:32 Outro 36:31

47: Sapling - A scalable, user-friendly source control system

December 24, 2022 40:46 20.07 MB Downloads: 0

Confused by the syntax of git’s rebase command? Overwhelmed with branch management? Check out Meta’s new git-compatible source control management system Sapling. Durham and Michael, two of the architects behind the recent open-source release, join Pascal on the podcast to discuss their plans for the project, how it was possible to extract one small part of Meta’s large SCM codebase and what the differences between Sapling, git and Mercurial are. Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy and https://mastodon.social/@passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Sapling: https://sapling-scm.com/ Review Stack: https://reviewstack.dev/ Timestamps: Intro 0:06 Durham and Michael Intro 1:18 What is Sapling? 2:56 git Compatibility 3:48 What's Available Today? 5:28 Sapling vs git 7:28 Branching Models 10:20 Stacks 13:09 Stacks and GitHub 17:28 Scaling Sapling 22:25 Extracting Sapling for Open Source 29:32 What's Next for Sapling 34:22 Outro 39:07 Bloopers 40:00

46: Cross-Platform Video Calling with RSYS

December 19, 2022 35:35 17.57 MB Downloads: 0

It’s the most wonderful time of the year: The time to talk about calling libraries that power most of our audio and video calls across Meta’s app. Alice, Ishan and Hani join Pascal to talk about how they replaced the different calling solutions with a library that’s extensible by the teams that choose to adopt it. But with great power comes great responsibility, so how does their team balance the desire for new features with the mandate to stay small, fast and reliable? Tune in for episode 46 to learn this and more! Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy and https://mastodon.social/passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Rsys: A smaller, faster video calling library for our apps: https://engineering.fb.com/2020/12/21/video-engineering/rsys/ Flipper: https://fbflipper.com/ Horizon Workrooms: https://www.meta.com/de/en/work/workrooms/ Timestamps: Intro 0:06 Team Overview 1:34 RSYS History 4:42 Design Tradeoffs 6:10 Testing Infrastructure 8:09 Usage and Support Model 11:04 Core Architectural Components 12:58 Changing Engines Mid-Air 16:48 Measuring Quality 19:30 Building on top of RSYS 21:34 Collaboration Model 24:22 Feature Development 26:41 Experimentation 28:43 Metaverse Strategy 29:51 What's Next for RSYS 33:26 Outro 34:36 Bloopers 35:24

45: Syncing GitHub to Monorepo with Jon

November 30, 2022 45:32 22.33 MB Downloads: 0

Back from a short hiatus, Pascal is joined by Jon to talk about the infrastructure that allows commit to sync between Meta's monorepo and GitHub. While ShipIt has been around for a while, allowing commits from the internal repository to sync out to GitHub, Diff Train is its younger brother to allow the inverse. This makes it possible for open-source-first projects like PyTorch to develop on GitHub and bring changes back into the monorepo without sacrificing security and reliability. Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/. Links: https://github.com/facebook/pyre-check https://github.com/facebookincubator/cinder https://github.com/facebook/hhvm https://github.com/facebook/fbshipit Timestamps: Intro 0:06 Intro Jon 1:49 Open-sourcing an internal project 7:26 Open Source Team @ Meta 10:22 Third-party dependencies 12:07 ShipIt 13:48 Diff Train 29:01 Most excited about 41:07 The GIL 42:29 Outro 44:22

BONUS: Comparing Company Cultures with Jay

August 31, 2022 46:25 44.67 MB Downloads: 0

Ever wondered how the culture of big companies like Meta, Microsoft and Amazon differ? Jay comes with a fairly unique perspective as he has now worked at all three of them. In his discussion with Pascal, he shares his views on the trade-offs that a company value like “Move Fast” brings along and how companies assign different weights to the value of making mistakes. Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Power On: The Story of Xbox: https://www.youtube.com/watch?v=AJYsA1jXf60 Timestamps: Intro 0:06 Jay Introduction 1:18 Business Engineering at Meta 2:43 Social Impact 5:35 Culture Shocks 8:24 The Value of Mistakes 14:15 Finding your Pace 16:14 Modes of Working in Different Teams 19:32 Expectations vs Reality 23:36 Workflows 30:02 Incidents 37:26 Internal Mobility 42:24 Outro 45:30 Bloopers 46:10

44: Building a Cross-App Messaging Platform

July 29, 2022 37:52 36.84 MB Downloads: 0

msys is the technology that underpins most of the messaging products Meta offers. What started as a small library in C wrapping sqlite is now used by many teams across the company and is now trying to address the developer experiences challenges that arise from the initial focus on speed and size above all else. Tune in to Pascal's interview to learn how Akshay and Chris are tackling this and other thorny issues.  Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Meta Tech Podcast Episode 37: Faster and Smaller Messenger for With Amy Meta Tech Podcast Episode 39: White Labeling Messenger for iOS with Amy Project LightSpeed: Rewriting the Messenger codebase for a faster, smaller, and simpler messaging app   Timestamps:   Intro 0:06 Introduction Chris 1:33 Introduction Akshay 2:54 msys overview 3:37 Products adopting msys 7:16 Building features with msys 13:06 Migrations 20:28 Optimising DevX 26:38 Web Client 33:30 What's Next for msys 34:40 Outro 36:50 Outtakes 37:45

43: Building for the metaverse with Cami

June 30, 2022 45:21 44.28 MB Downloads: 0

Cami returns to the Meta Tech Podcast, with now having 18 months of AR/VR experience under her belt. Cami is excited to share what developers can now do on the Quest platform. In this episode, Pascal and Cami discuss new SDKs for motion controls, voice and spatial objects; and for creators without programming experience - there’s Horizon Worlds.  Cami, as a Developer Advocate, shares her expertise whilst being acutely aware of areas that require careful consideration. To find out more from Cami and the exciting updates on Quest, tune into episode 43 of the Meta Tech Podcast. Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/.   Links: Display prototypes on Zuck’s Facebook: https://www.facebook.com/4/videos/355247026677540/ Boz to the Future on Display Tech: https://www.facebook.com/1681/videos/390455039578133/ Presence Platform Announcement: https://developer.oculus.com/blog/introducing-presence-platform-unleashing-mixed-reality-and-natural-interaction-for-oculus-developers/?locale=en_GB Presence Platform Developer Portal: https://developer.oculus.com/presence-platform/ Cami on Twitter: https://twitter.com/cwillycs Keep talking and nobody explodes: https://www.oculus.com/experiences/quest/2010043642376517/?locale=en_GB wit.ai: https://wit.ai/   Timestamps: Intro 0:06 Cami: Reintro 2:01 Horizon Worlds 3:22 Presence Platform SDK 7:59 Voice SDK 12:57 Insights SDK 17:34 Next-Gen Displays 24:14 Keep Talking and Nobody Explodes 28:20 Building for Horizon 31:37 ELI5 on YouTube 36:59 Meta Connect 42:51 Outro 44:14

42: Building People-Centric Apps with Maria

May 31, 2022 42:13 41.03 MB Downloads: 0

The approach we take to building the Facebook app is based around three adjectives: trustworthy, people-centric and unified. In this episode, Pascal talks with Maria who is a director of engineering for product architecture and product excellence. They discuss what it means for a culture that is known for being driven by metrics to become more people-centric. What are examples of metrics that are aligned with people goals and when do they fail to capture them? Tune in to hear the answers to these questions and much more. Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Rachel Nabors on The Diff: https://thediffpodcast.com/docs/episode-12 Meet the Developers: Mobile Edition (Pritesh Nandgaonkar): https://developers.facebook.com/blog/post/2022/05/23/meet-the-developers-pritesh-nandgaonkar/ Meta Open Source on YouTube: https://www.youtube.com/c/FacebookOpenSource Meta Tech Podcast Episode 29: Design Systems with Sriram: https://pca.st/u8r4u6h6 Meta Tech Podcast Episode 9: Android Bytecode Optimisation with Emma https://pca.st/J3cn    Timestamps: Intro 0:06 The Diff: Episode 12 1:23 Meet The Developer: Prish 1:38 Meta Open Source on YouTube 2:01 Intro 2:26 Intro Maria 2:36 Craft in FB App 5:15 Metrics vs People? 6:40 Unquantifiable Quality Goals 10:14 Dropping Facial Recognition 11:38 Dynamic Goals in a Dynamic World 13:21 Driving Cultural Change 15:49 Average vs Power Users 18:53 Metrics for Quality 22:33 Dev Tools' Role for Quality 29:12 Supporting People at Meta 33:38 Most Exciting Upcoming Change 39:25 Outro 40:43 Bloopers 42:00

41: Earth Week Special - Carbon Explorer with Bilge

April 22, 2022 30:07 29.25 MB Downloads: 0

For our second special for Earth Week, we are talking to Bilge who works as a research scientist at Meta AI. Her open-source project Carbon Explorer evaluates solutions to make data centres operate on 24/7 renewable energy. Why this is easier said than done and how engineers can help within their day-to-day work to reduce their carbon footprint are among the many things Pascal and Bilge discuss in this episode.   Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Carbon Explorer: https://github.com/facebookresearch/CarbonExplorer Holistic Approach for Designing Carbon Aware Datacenters: https://arxiv.org/abs/2201.10036 Open Catalyst: https://opencatalystproject.org/ Open Catalyst SchrepTech Interview: https://ai.facebook.com/blog/how-ai-is-helping-address-the-climate-crisis/ Timestamps: Intro 0:05 Intro Bilge 2:18 Optimising for the Environment 4:01 Carbon Explorer 5:02 Mitigations for Renewable Intermittency 7:17 Operational and Embodied Footprints 10:57 Motivations for Carbon Explorer 13:06 Battery Storage 14:36 Renewable Curtailment 15:52 Empowering Engineers 18:20 Carbon Intensity APIs 19:22 AI Carbon Intensity Forecasts 22:07 Carbon Metrics 23:17 Where to Learn More 25:38 Outro 27:32 Bloopers 29:45

40: Earth Week Special - Green AI with Ramya

April 19, 2022 36:49 35.79 MB Downloads: 0

The most recent IPCC report has reiterated that the climate crisis is an all hands on deck situation. We all need to think about the impact our actions have on the planet that provides our life support system. Ramya is a TPM on the Meta AI team and analyses the impact AI has, as it grows superlinearly, on energy use and carbon emissions. Her recent work on Green AI identifies ways for reducing that footprint without limiting the options engineers have for building great products for connecting people. Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/.   Acronyms: LCA: Life Cycle Assessment PUE: Power Usage Efficiency Links: Sustainable AI: Environmental Implications, Challenges and Opportunities: https://arxiv.org/abs/2111.00364 Make an Impact for Earth Day: https://about.fb.com/news/2022/04/make-an-impact-for-earth-day/ Green AI SchrepTech: https://ai.facebook.com/blog/how-ai-is-helping-address-the-climate-crisis/ Timestamps: Intro 0:05 Intro Ramya 2:13 The Cost of AI 3:05 Measuring AI's Carbon Footprint 11:00 Trade Offs 13:28 Calculating the Carbon Intensity 16:01 Mitigation Options 18:36 Cultural Changes 25:35 Societal Value 26:13 Running AI on Edge Devices 29:02 What's Next? 32:33 Outro 34:55

39: White Labeling Messenger for iOS with Amy

March 11, 2022 38:01 36.8 MB Downloads: 0

When Amy joined the Workplace team nearly seven years ago (back then still under the name Facebook for Work), it became clear that it would require a messaging service. While there were already a few options available, none of them was designed to be plugged into a new app. That's when Amy and her team decided to take on white labeling Messenger for iOS to turn it into what would become Workplace Chat. Amy and Pascal discuss the challenges of taking a huge app that is under constant development and adding your own functionality on top. After many years on Workplace, Amy recently switched teams and now works on Lexical, "an extensible text editor library that does things differently". To find out why you should get excited about the upcoming open source release of the library, tune in! Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/. Links: Lexical: https://lexical.dev/ Workplace: https://www.workplace.com/ Timestamps: Intro 0:06 Introducing Amy 1:54 Joining Workplace 3:54 Early Days at Facebook for Work iOS 6:38 Whitelabeling Messenger 8:10 Project Workspeed 10:23 msys 14:39 End-to-End Encryption 17:50 Workplace Chat for Desktop 19:33 Unified Editor 24:27 Lexical 28:01 Text Rendering Models 34:16 Outro 37:02

38: From Sales to Tech - How Kevin Made The Switch

February 08, 2022 42:39 41.44 MB Downloads: 0

Kevin has had an unusual career path that led him to an engineering role at Meta. He first joined the company in a sales role before he moved into a more product-focused position. Working closely with engineers, Kevin decides to pursue a career in software development himself. Instead of dropping out of his job to get formal education in the space, he takes online courses and within less than a year smashes the internal interview process. To learn what his thinking behind the change was and which resources were particularly helpful, tune in to episode 38!   Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://www.metacareers.com/.   Links: Coursera Datastructures and Algorithms classes: https://www.coursera.org/courses?query=data%20structures%20and%20algorithms Udemy: https://www.udemy.com/   Timestamps: Intro 0:06 Introduction Kevin 1:22 Learning to Code 3:38 Learning Resources 12:50 Deciding When to Stop 16:42 Interview Prep 21:57 The Big Day 24:45 Dealing With Imposter Syndrome 29:53 Interviewing is Broken 38:41 Outro 40:52

37: Faster and Smaller Messenger for iOS With Amy

January 31, 2022 40:25 39.27 MB Downloads: 0

New year, new us! Inside Facebook Mobile is now the Meta Tech Podcast but Pascal will continue to bring you stories about mobile development and many other topics.  For this episode's interview, we're tackling one of the few remaining big apps we never had a guest from: Messenger. Amy worked on Messenger for 3 years before recently moving on to Reality Apps to work on AR.   Amy discusses with Pascal how Messenger for iOS was rewritten as part of Project Lightspeed to make it smaller and faster. They used a range of low-level hacks while providing high-level abstractions that product teams could safely and productively build on top of. Amy was also the first one to prototype with Catalyst and Meta and has some important tips for you on how not to accidentally wipe your Mac while doing so.  Got feedback? Send it to us on Twitter (https://twitter.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://facebookcareers.com. Links: Project LightSpeed: https://engineering.fb.com/2020/03/02/data-infrastructure/messenger/ Mac Catalyst: https://developer.apple.com/mac-catalyst/ Buck: https://buck.build/ Remodel: https://github.com/facebook/remodel - Remodel is a tool that helps iOS and OS X developers avoid repetitive code by generating Objective-C models that support coding, value comparison, and immutability.   Timestamps: Intro 0:06 Introduction Amy 2:25 Messenger Culture 3:37 Building with Buck 5:38 Catalyst 6:27 Project Lightspeed 17:13 Remodel 23:55 Image Asset Optimisations 28:50 Theming 36:44 What's Next for Amy? 38:21 Outro 39:21 Bloopers 39:54

36: Developer Experience with Chandrika

December 17, 2021 43:28 42.18 MB Downloads: 0

Keeping engineers effective is not a small task when you work at Meta’s scale. Many of the tools you take for granted simply break or become unbearably slow. Chandrika’s team looks after developer experience at Meta and takes a holistic approach that spans the editing experience (IDEs, editors), builds, continuous integration and even custom calendar tooling. Her team ensures that as new platforms, for instance AR/VR, and languages like Swift and Kotlin emerge, our infrastructure is ready. Got feedback? Send it to us on Twitter (https://twitter.com/insidefbmobile), Instagram (https://instagram.com/insidefbmobile) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://facebookcareers.com. Links: The Diff Podcast: https://thediffpodcast.com/docs/episode-10/ Meta Connect Keynote: https://fb.watch/9YydoWHMEE/ Jest: https://jestjs.io/   Timestamps: Intro 0:06 News: The Diff is back 1:25 Chandrika before Meta 1:50 Meta vs other Megacorps 9:57 DevEx at Meta 12:05 Different Dev Infra Teams 23:18 Unexpected Challenges 26:45 Kotlin & Swift 30:34 Measuring Developer Experience 35:53 App Health & Perf 37:46 Cross-App Dev 40:12 Outro 42:17

35: Facebook App Health with Jon

November 11, 2021 34:58 33.92 MB Downloads: 0

Did you know that you can "rage shake" your phone to create a bug report in most Meta apps? If you did, have you ever wondered what happened after you hit submit? In this episode's interview, Pascal talks to Jon about App Health and how his team ensures that despite thousands of engineers shipping code every day, the apps remain reliable and fast. Got feedback? Send us an email to mobilepodcasts@fb.com, tweet us at @insidefbmobile (https://twitter.com/insidefbmobile), DM us on Instagram (https://instagram.com/insidefbmobile) and don’t forget to follow our host @passy (https://twitter.com/passy). Fancy working with us? Check out https://facebookcareers.com. Links: Flipper Litho Error Boundaries Meet the Rustaceans: Digant Kasundra ELI5: Metro - JavaScript Bundler for React Native IFBM 7: Performance and lnstrumentation with Ariane gCPU Paper: A Real-time Framework for Detecting Efficiency Regressions in a Globally Distributed Codebase Timestamps: Intro 0:06 Jon Intro 1:30 App Health Mission 2:58 Rage Shake & Fly Trap 5:27 Life of a Regression 8:49 Experiments and App Health 13:47 Tracking Down Perf Regressions 16:13 Soft Errors 18:54 Favourite Tools 23:35 Backend Regressions 25:31 Rolling out a Fix 28:00 gCPU 29:45 Wrapping Up 32:12 Outro 33:20 Bloopers 34:04