Meta Tech Podcast

The basic version of Threads for web was built in just under three months by two engineers, mirroring the nimble engineering practices we talked about on this podcast before when it came to launching Threads for Android and iOS. In this episode, Pascal is joined by Ally and Kevin, two engineers on the Threads Web team. They talk about how shared infrastructure with other Meta web properties allows them to move fast and how they manage to balance the need to ship new features with the desire to craft delightful experiences for their users. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links Threads: https://threads.net StyleX: https://stylexjs.com/ FlowJS: https://flow.org/ Introducing Meta Llama 3: https://ai.meta.com/blog/meta-llama-3/ Building custom silicon for the future of AI: https://www.metacareers.com/life/building-custom-silicon-for-the-future-of-ai Building Meta’s GenAI Infrastructure: https://engineering.fb.com/2024/03/12/data-center-engineering/building-metas-genai-infrastructure/ Timestamps Intro 0:06 Intro Ally and Kevin 1:44 Why focus on Web? 2:48 Kevin's contributions 4:42 Focus on craft 6:18 Editing Threads 7:34 Ally's contributions 10:40 Prioritising delight and shipping features 12:02 Launching Threads Web 13:30 Shared Infra 16:13 Tech Stack 19:15 The DevX of Meta www 23:51 Challenges 30:57 Favourite bit of polish 34:32 Outtakes 39:18

Every day, trillions of image download requests are made from Meta’s family of apps. Zuzanna works on the Media Platform Team that owns the entire flow from serving images from the CDN to displaying the pixels on your phone. One of the project she and her team recently worked on was rolling out HDR images to Instagram and Threads and in this episode’s interview, Zuzanna tells show host Pascal how they partnered with large phone manufacturers to develop and roll out the new feature. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links Fresco: https://frescolib.org/ Timestamps Intro 0:06 Intro Zuza 1:44 Image Infra Team 3:23 The scale of images at Meta 5:10 Measuring quality 10:01 HDR photos 12:13 HDR file formats 19:02 HDR photo availability today 22:34 Partnering with phone vendors 30:40 Why photos after videos? 32:27 Outro 36:22

Distributing binaries and toolchains to developers is a pain but DotSlash makes it a breeze. Instead of committing large, platform-specific executables to your repository, DotSlash combines a fast Rust program with a JSON manifest prefixed with a #! to transparently fetch and execute the binary you need. Tune in to our interview with Andres and Michael to learn more. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links Simple Precision Time Protocol at Meta: https://engineering.fb.com/2024/02/07/production-engineering/simple-precision-time-protocol-sptp-meta/ Meta Time libraries on GitHub: https://github.com/facebook/time DotSlash - Simplified executable deployment: https://engineering.fb.com/2024/02/06/developer-tools/dotslash-simplified-executable-deployment/ DotSlash website: https://dotslash-cli.com/ DotSlash on GitHub: https://github.com/facebook/dotslash Timestamps Intro 0:05 Intro Andres 2:30 Intro Michael 3:39 Andres's Projects at Meta 3:54 Michael's Projects at Meta 5:00 What is DotSlash? 5:30 DotSlash vs LFS 6:04 DotSlash vs buck2 run 7:08 Where is DotSlash used at Meta? 8:45 How does DotSlash work? 9:37 DotSlash on Windows 13:15 How DotSlash is built 16:21 Bundling the rust toolchain 17:14 Automated DotSlash file generation 20:33 DotSlash and remote execution 24:53 Storage providers 26:27 Why open-source? 30:05 Limitations 34:17 Cache Eviction 36:59 Outro 39:22 Bloopers 40:15

For the second time in just a few months, we are talking Python on the Meta Tech Podcast. Python 3.12 features a whole range of new features, many of which were contributed by Meta. Carl and Itamar join Pascal to talk about their contributions to the latest release, including new hooks that allow for custom JITs like Cinder, Immortal Objects, improvements to the type system, faster comprehensions and much more. In their discussion, they talk not just about how and why those features were built but also the process of upstreaming and engaging with the community. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links “Lazy is the new fast: How Lazy Imports and Cinder accelerate machine learning at Meta” - https://engineering.fb.com/2024/01/18/developer-tools/lazy-imports-cinder-machine-learning-meta/ “How Meta built the infrastructure for Threads” - https://engineering.fb.com/2023/12/19/core-infra/how-meta-built-the-infrastructure-for-threads/ Cinder on GitHub - https://github.com/facebookincubator/cinder “Meta contributes new features to Python 3.12” - https://engineering.fb.com/2023/10/05/developer-tools/python-312-meta-new-features/ Timestamps Intro 0:06 Carl Intro 2:09 Itamar Intro 3:27 Teams and Missions 5:10 Python 3 Faster Coroutines 8:57 Code Watchers and JIT Hooks 12:10 When to upstream 13:53 How to upstream to CPython 16:19 History of Cinder 21:35 Why not upstream Cinder? 25:48 Cinder hooks in CPython 29:34 Free Threading 34:10 Outro 37:08

For this last episode of 2024, Pascal talks with Devi, an AI research director at Meta. They talk about the history of AI at Meta, some of the basic terms, how Meta's approach to developing and using AI differs notably from other companies and what the future has in store. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links Meta AI Blog: https://ai.meta.com/ Purple Llama: https://ai.meta.com/blog/purple-llama-open-trust-safety-generative-ai/ AI Alliance: https://ai.meta.com/blog/ai-alliance/ Audiobox: https://ai.meta.com/blog/audiobox-generating-audio-voice-natural-language-prompts/ Emu Video and Emu Edit: https://ai.meta.com/blog/emu-text-to-video-generation-image-editing-research/ Meta AI Agents: https://about.fb.com/news/2023/09/introducing-ai-powered-assistants-characters-and-creative-tools/ Timestamps Intro 0:00 Introduction Devi 2:27 AI vs ML 4:00 History of AI at Meta 6:03 Deep learning and LLMs 9:32 LLMs vs GenAI 11:42 Multi-modal models 12:21 Meta's AI agents 14:33 Meta's open approach to AI 16:53 Image and video generation and editing 22:28 Most exciting future AI developments 27:17 Outro 28:57

We’re jumping into our time machine and going back to 2018 for an interview with Will B. about the various twists and turns that led to the creation of Instagram Stories. We will be back with a fresh interview next month. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links https://github.com/facebookarchive/reboundhttps://origami.design/ Timestamps Intro 0:06 Will Bailey 1:14 Early FB iOS app 7:16 Release Trains 11:52 The End of HTML5 13:29 Migration to Native 16:05 Facebook Home 17:02 Design Collaboration 22:03 Instagram 26:33 Slingshot 27:57 Instagram for Android 29:54 Instagram Stories 35:37 Rebound 41:25 Outro 44:41

Python at Meta is huge. Not only does it famously power Instagram's backend, but it underpins our configuration systems, much of our AI work and many services. Amethyst joins Pascal for this episode of the Meta Tech Podcast to talk about how the Python Foundation Team works to improve the developer experience of everyone working with Python at Meta and Fixit 2, the freshly open-sourced linter framework built on top of libcst. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links Fixit 2 announcement post: https://engineering.fb.com/2023/08/07/developer-tools/fixit-2-linter-meta/ Fixit: https://fixit.readthedocs.io µfmt: https://ufmt.omnilib.dev µsort: https://usort.readthedocs.io LibCST: https://libcst.readthedocs.io 5 Things You Didn’t Know About Buck2: https://engineering.fb.com/2023/10/23/developer-tools/5-things-you-didnt-know-about-buck2/ Scheduling Jupyter Notebooks at Meta: https://engineering.fb.com/2023/08/29/security/scheduling-jupyter-notebooks-meta/ Timestamps Intro 0:06 Intro Amethyst 1:57 Production vs Software Engineering 3:41 PE for language teams 5:40 Python at Meta 6:58 Python3 migration 10:15 Projects on the Python Foundation Team 16:30 libcst and codemods 21:55 What Python looks like at Meta 25:53 Meta's involvement in the Python community 30:30 The importance of lints at Meta 35:13 Why another linter? 39:11 Favourite lint 46:26 Outro 48:17 Bloopers 48:54

Threads went from idea to 100M users in just about five months. This would not have been possible without building on top of Meta's existing systems and infrastructure. Join Pascal as he speaks with Joy, Cameron and Richard, three engineers from the Threads team who worked on backend, iOS and Android, respectively to learn about the challenges they faced along the way. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links Threads: https://threads.net Threads: The inside story of Meta’s newest social app - https://engineering.fb.com/2023/09/07/culture/threads-inside-story-metas-newest-social-app/ Litho: https://fblitho.com/ Timestamps Intro 0:00 Introductions 0:56 Intro: Cameron 1:42 Intro: Joy 2:06 Intro: Richard 2:30 Early Days at Threads 3:03 Specialisations 6:52 Why built on top of IG? 7:18 iOS and Android approaches 10:17 UI Frameworks 12:00 Code sharing on server 15:36 What broke? 20:04 How has the team changed? 23:02 Favourite moments 25:30 Outro 29:45 Outtakes 31:03

For episode 55, Pascal speaks with Katherine and returning guest Dustin, two software engineers at Meta about how to ship code at Meta. Why do we have a monorepo? Why and how do we do pre-commit code review? What does our CI infrastructure look like? Get the answers to these questions and many more in this episode of the Meta Tech Podcast. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links The evolution of Facebook’s iOS app architecture - Engineering At Meta: https://engineering.fb.com/2023/02/06/ios/facebook-ios-app-architecture/ https://pca.st/episode/429e9f38-6537-43e3-b929-fbeeda326ed5 Timestamps Intro 0:06 Intro Katherine 1:55 Dustin's Origin Story 4:38 Topic Intro 6:28 Why Monorepo(s) 7:18 What Makes Monorepos Hard? 12:15 Why do we Have so Many Files? 17:31 Who Owns Stuff? 25:29 Life of a Diff 28:58 Writing Bots Writing Code Writing Bots 34:16 Finding Reviewers 38:46 Why Are Things Not Constantly on Fire? 41:43 Outro 47:47 Outtakes 48:46

In April, WhatsApp announced the launch of a new cryptographic security feature to automatically verify a secured connection based on key transparency. Key transparency helps strengthen the guarantee that end-to-end encryption provides to private, personal messaging applications in a transparent manner available to all. Rolling out a feature like this to WhatsApp's user base is not a small feat and requires some clever engineering to scale to the billions of users relying on WhatsApp to stay in touch with friends, family and business. Pascal is joined by Sean and Kevin to discuss what Key Transparency means in practice and the various challenges they encountered as they scaled it up to billions of users. Got feedback? Send it to us on Threads (https://threads.net/@metatechpod), Twitter (https://twitter.com/metatechpod), Instagram (https://instagram.com/metatechpod) and don’t forget to follow our host @passy (https://twitter.com/passy, https://mastodon.social/@passy, and https://threads.net/@passy_). Fancy working with us? Check out https://www.metacareers.com/. Links Infer: https://fbinfer.com/ Infer on GitHub: https://github.com/facebook/infer MTP Episode 18 about Infer: https://pca.st/5U9V Deploying key transparency at WhatsApp - Engineering at Meta: https://engineering.fb.com/2023/04/13/security/whatsapp-key-transparency/ GitHub - facebook/akd: An implementation of an auditable key directory: https://github.com/facebook/akd/ Parakeet: Practical Key Transparency for End-to-End Encrypted Messaging: https://www.ndss-symposium.org/ndss-paper/parakeet-practical-key-transparency-for-end-to-end-encrypted-messaging/ SEEMless: Secure End-to-End Encrypted Messaging with less trust: https://eprint.iacr.org/2018/607 Coniks: Bringing Key Transparency to End Users: https://www.usenix.org/conference/usenixsecurity15/technical-sessions/presentation/melara IETF Working Group on Key Transparency: https://datatracker.ietf.org/wg/keytrans/about Timestamps Intro 0:06 News Update: Infer turns 10 1:34 Interview Intro 4:27 Intro Kevin 4:45 Intro Sean 6:07 WhatsApp's mission 6:47 PETs 7:58 E2E basics 8:59 Key transparency 10:32 Crypto community response 18:20 End-user changes 19:57 Technical challenges and zero-knowledge proofs 23:18 AKD 28:27 Internal deployment 32:02 Outro 42:16 Bloopers 43:05

Red Team X is a security team at Meta that is responsible for finding and exploiting vulnerabilities in third-party products that could impact Meta's own security. The team acts as a hybrid between a traditional red team, which focuses on probing their own organisation's systems and products for vulnerabilities, and an elite bug-hunting group. The team was founded by Vlad I. in 2020 when the pandemic and the sudden shift to Work From Home challenged various previously-held assumptions about security. In his discussion with Pascal, Vlad explains the roles of different security teams within Meta, how they go about prioritising the highest-impact targets to exploit and how they work with vendors to ensure not just Meta but the entire world benefits from the fixes produced. 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: The Diff episode about Velox: https://thediffpodcast.com/docs/episode-17 Risky Business Podcast: https://risky.biz/ RTX Blog: https://rtx.meta.security RTX Disclosures: https://rtx.meta.security/bugs RTX in WIRED: https://www.wired.com/story/facebook-red-team-x-vulnerabilities/ Timestamps: Intro 0:06 Vlad Intro 1:55 Red Teaming 2:43 Staying up-to-date 6:34 Different team colours 10:02 Defence-in-depth 12:44 Red Team X 15:57 Hardware v Software 19:43 Focus areas 21:29 Prioritising requests 22:44 Notable RTX Disclosures 26:05 Vulnerability disclosure policy 28:52 Getting into offensive security 38:48 Outro 40:51

PyTorch is now one of the most popular machine learning frameworks out there but that was not a foregone conclusion when it was released in 2016. Our host Pascal is joined by Suraj, a developer advocate here at Meta, to dissect the history of PyTorch and look at the factors that contributed to its success. That includes understanding your target audience, maintaining backwards compatibility, fostering a helpful community and so much more. You don't need to be an expert in PyTorch to enjoy the discussion as Suraj explains all the basics. 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: Meta Open Source Blog: Creating Safe Spaces for Underrepresented Individuals in Open Source Communities - https://developers.facebook.com/blog/post/2023/05/31/creating-safe-spaces/ PyTorch Developer Podcast - https://pytorch-dev-podcast.simplecast.com/ PyTorch - https://pytorch.org/ PyTorch on GitHub - https://github.com/pytorch/pytorch Announcing the PyTorch Foundation: A new era for the cutting-edge AI framework - https://ai.facebook.com/blog/pytorch-foundation/ Timestamps: Intro 0:05 Suraj Intro 1:52 What is PyTorch? 4:39 History of PyTorch 5:33 Choosing a Target Audience 7:27 Python and Performance 11:20 Design Decisions 19:04 OSS Governance and Community 21:11 PyTorch 2.0 25:47 How to get started 28:32 Outro 30:14 Bloopers 32:16

For episode 51, Pascal speaks with Neil and Marie, two of the engineers behind Buck2, our open source, large scale build system. Thousands of developers at Meta are already using Buck2 and performing millions of builds per day that on average complete in half the time of Buck1 builds. Marie and Neil discuss the design choices that make Buck2 so much faster and the various challenges they faced in engineering and open sourcing the build system. 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 https://engineering.fb.com/2023/04/06/open-source/buck2-open-source-large-scale-build-system/Buck2: https://buck2.build/ Buck2 on GitHub: https://github.com/facebook/buck2 Build Systems à la Carte - https://www.microsoft.com/en-us/research/uploads/prod/2018/03/build-systems.pdf Lexical YouTube clip: https://www.youtube.com/watch?v=Vpv0BYhhlak Lexical for iOS: https://github.com/facebook/lexical-ios Timestamps Intro 0:06 Intro Marie 1:30 Intro Neil 2:57 Why a custom build tool? 4:21 Rewriting Buck 6:49 Buck2 vs Bazel 8:49 Building language support 12:06 Buck2 as a developer 13:15 Upgrade from Buck1 to Buck2 15:05 How is Buck2 faster? 16:31 Rust and Profiling 18:44 From Python to Starlark 25:54 Open-Sourcing 28:18 Outro 32:15

If you hear privacy and your first thought is laborious processes and access management, this interview may be just as mind-expanding for you as it was for our host Pascal. He is joined by Alex and Haozhi who talk about the Anonymous Credential Service (ACS), a highly available multitenant service that allows clients to authenticate in a de-identified manner. They discuss the cryptographic primitives powering the service and the various challenges they encountered scaling it to support Meta's products. 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 How Meta enables de-identified authentication at scale - https://engineering.fb.com/2022/03/30/security/de-identified-authentication-at-scale/ Open-sourcing Anonymous Credential Service - https://engineering.fb.com/2022/12/12/security/anonymous-credential-service-acs-open-source/ ACS on GitHub - https://github.com/facebookresearch/acs ReactJS - The Documentary - https://www.youtube.com/watch?v=8pDqJVdNa44 Timestamps Intro 0:12 Alex and Haozhi Intro 1:22 Cryptography and Privacy 2:47 Team Mission 3:35 Data Minimisation 4:28 PETs 5:13 Why authenticate? 8:39 ACS under the hood 10:06 ACS Architecture 16:02 Challenges 21:03 ACS in Open Source 26:36 Key-Derivation Functions 29:22 How to get started 32:10 Outro 33:47 Bloopers 34:29

Lisa works on the Dev Craft team at Instagram that embarked on a journey to bring Kotlin to the Instagram for Android code base a little over three years ago. Now, nearly half of the large codebase is migrated and over 80% of newly committed code is in Kotlin. Tune in to hear what the unique challenges of bringing a new language to an existing app are and what it means for build speed, IDE experiences and developer happiness. 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 Meta Engineering Blog: How Meta brought AV1 to Reels - https://engineering.fb.com/2023/02/21/video-engineering/av1-codec-facebook-instagram-reels/ Source-only ABIs for Java - https://engineering.fb.com/2017/11/09/android/rethinking-android-app-compilation-with-buck/ Timestamps Intro 0:06 Intro Lisa 1:27 Dev Craft at Instagram 3:03 Building DevX Partnerships 3:56 The History of Kotlin at Instagram 6:22 Declarative UI 18:29 Build Speed Challenges 20:25 Source-Only ABIs 23:19 IDE Performance 26:19 Kotlin at IG in 2023 27:15 Outro 32:02 Bloopers 33:07

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: Intro0:06Intro Ryan1:40Transcoding Video at Instagram2:52Codecs and Tradeoffs5:33Client Support7:13Where did the compute go?9:15ABR10:59Progressive/Non-ABR Encodings12:31Saving Encoding Time13:10Testing the Changes17:39Results26:43Popularity Predictions28:3236:31

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: Intro0:06Durham and Michael Intro1:18What is Sapling?2:56git Compatibility3:48What's Available Today?5:28Sapling vs git7:28Branching Models10:20Stacks13:09Stacks and GitHub17:28Scaling Sapling22:25Extracting Sapling for Open Source29:32What's Next for Sapling34:22Outro39:0740:00

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: Intro0:06Team Overview1:34RSYS History4:42Design Tradeoffs6:10Testing Infrastructure8:09Usage and Support Model11:04Core Architectural Components12:58Changing Engines Mid-Air16:48Measuring Quality19:30Building on top of RSYS21:34Collaboration Model24:22Feature Development26:41Experimentation28:43Metaverse Strategy29:51What's Next for RSYS33:26Outro34:3635:24

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-checkhttps://github.com/facebookincubator/cinderhttps://github.com/facebook/hhvmhttps://github.com/facebook/fbshipit Timestamps: Intro0:06Intro Jon1:49Open-sourcing an internal project7:26Open Source Team @ Meta10:22Third-party dependencies12:07ShipIt13:48Diff Train29:01Most excited about41:07The GIL42:2944:22

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: Intro0:06Jay Introduction1:18Business Engineering at Meta2:43Social Impact5:35Culture Shocks8:24The Value of Mistakes14:15Finding your Pace16:14Modes of Working in Different Teams19:32Expectations vs Reality23:36Workflows30:02Incidents37:26Internal Mobility42:24Outro45:30Bloopers46:10