For the first time, Rachel and Pascal are joined by a guest from WhatsApp. Silky walks the two through a staggering array of optimisations WhatsApp deploy to make sure that text, media and documents arrive quickly, reliably and safely on the other end. They discuss going from five to six nines of reliability for Facebook’s distributed blob store, POPs, FNAs, and fighting abuse on an end-to-end encrypted platform. As ever, before the interview, Pascal and Rachel discuss some news from the Open Source world, including React Native documentation updates, an exciting contracting opportunity on the Docusaurus project and the latest Facebook Open Source statistics. Please do send us feedback! You can reach us via email mobilepodcasts@fb.com, Twitter (@insidefbmobile) or Instagram (insidefbmobile). Topics React Native Docs: https://reactnative.dev/docs/getting-started Docusaurus Contract: https://profacebook.applytojob.com/apply/hZPoVr1Eoj/Front-End-Engineer-V Open source year 2019 in review: https://engineering.fb.com/open-source/open-source-2019/ Evolution of WhatsApp within Facebook’s data centers: https://atscaleconference.com/videos/evolution-of-whatsapp-within-facebooks-data-centers/ WhatsApp on how it’s fighting bulk messaging and fake accounts: https://venturebeat.com/2019/02/06/whatsapp-on-how-its-fighting-bulk-messaging-and-fake-accounts/ How WhatsApp Reduced Spam for Over 1 Billion People: https://developers.facebook.com/videos/f8-2017/how-whatsapp-reduced-spam-for-over-1-billion-people/ Timestamps Intro    0:05 News: React Native Docs    1:02 News: Docusaurus Contractor    1:52 News: Open Source in Review 2019    3:10 Interview with Silky    5:05 Sharding Graph Databases    6:10 Getting into CompSci    7:45 Scaling an Exabyte Blob Store    9:00 Benefits of Shared Infrastructure    13:46 Going from 5 to 6 Nines    17:19 POPs    18:09 ISP-Level Caches    19:19 Making WhatsApp New-Year-Safe    22:13 Fighting Encrypted Abuse at WhatsApp    25:00 Encrypted Media Forwarding    32:45 ML Teams at FB    35:42 Transition to Management (and Back)    37:37 Outro    43:56 Aftershow/Outtakes    48:55 Harley Quinn: Birds Of Prey    50:59