Engineering Blogs

We're rebuilding GitHub's Git infrastructure while GitHub keeps running, creating a foundation for agent-scale software development. The post Building Git infrastructure for agent-scale development ap...

How we capture real production database traffic at Airbnb and replay it offline to load-test, plan capacity, and de-risk upgrades.By: Zuofei Wang, Erluo LiIntroductionAt Airbnb, MySQL-compatible datab...

Michele Ceccacci; Software Engineer I | Jason Coffman; Sr. Software Engineer | Colm O’Shaughnessy; Software Engineer II | Laura Palmer; Staff Product Manager | Adam Podraza; Manager, Engineering | Sur...

Meta’s public time service now speaks NTS (Network Time Security, RFC 8915) at nts.meta.com. Packets are authenticated, so a device can verify the time came from us and was not modified on the way. Ou...

Token billing is useful infrastructure, but usually a bad customer-facing pricing model. Your invoice should define the value your product delivers, not break down what it cost you to create it....

Open USD (OUSD), a stablecoin built for global money movement, is now available across Stripe. Businesses can use OUSD to manage funds, make payments, and offer new financial services....

How Airbnb uses proximity signals to personalize without relying on individual user history.By: Wei Jiang, Bin Xu, Bharathi Thangamani, Weiwei Guo, Sundar Srinivasavaradhan, Tracy Yu, Huiji Gao, Swapn...

As agents take on more purchases, agent builders have increasingly asked us to help agents navigate checkout and earn consumer trust. Today, we’re sharing three major improvements to support this broa...

At the “great recalibration”-themed travel conference, Airbnb CEO Brian Chesky called AI “an existential risk” to his company and “literally the best thing to ever happen” to it in the same discussion...

By Dhruv PratapIntroductionOrganizations that have been around for a while usually run two identity systems side by side. One belongs to the cloud provider: IAM roles, instance profiles, execution rol...

Qianrui Zhang | Sr Software Engineer, Logging PlatformKanchi Masalia | Software Engineer II, Stream Processing PlatformLiang Mou | Sr Staff Software Engineer, Logging PlatformYi Pan | Principal Engine...

How we fully migrated github.com away from CSS-in-JS. The post Improving site performance by shipping more CSS appeared first on The GitHub Blog. ...

We believe glasses are the best form factor for having AI help throughout your day. They can understand your personal context better than other kinds of devices and keep you present without picking up...

How we rebuilt the diff surface in the GitHub Copilot app to open a million-line pull request with hundreds of inline review comments. The post Rendering huge pull requests in the GitHub Copilot app a...

We analyzed billions of transactions on Stripe from January 2022 to March 2026 to understand how card fraud patterns differ by region and country, what's driving those differences, and how businesses ...

We’re open-sourcing Rebalancer, the assignment-problem solver that has been used to solve resource allocation problems throughout Meta for over nine years. Rebalancer separates several related c...

Petal, the next step in Meta’s subsea innovation, will be the first subsea cable to deliver petabit capacity at transoceanic distances, connecting France and the United States over approximately 7,000...

Introducing composable, module system native and agent friendly command line tools for modern Java developmentBy Danny Thomas, JVM Ecosystem TeamRecent work on the Java language to pave the on-ramp ha...

Last year, Stripe data shows fraud attempts against travel and leisure businesses hit a four-year high. We analyzed payment activity from more than 200,000 active travel and leisure businesses on Stri...

How two new Chronon capabilities, Push Mode and NRT Model Transform, allows us to provide more relevant search results instantly as a guest explores, rather than waiting for the next batch run.By: Pen...

Authors: Longyu Zhao (Staff Machine Learning Engineer), Gwendolyn Zhao (Staff Machine Learning Engineer), Peng Yan (Senior Machine Learning Engineer), Yuanlu Bai (Senior Machine Learning Engineer), Yu...

The SaaSpocalypse was a useful warning for the software industry, but SaaS platforms that help businesses run core operations are more deeply embedded. New platform businesses on Stripe are up 182% ye...

Quality and reliability have always been a point of pride for Spotify. We run an extraordinarily complex... The post AI Changed How Spotify Builds. What We Learned (and Fixed) About Quality at Higher ...

How Airbnb’s agent harness transforms unstructured data exploration by encoding scientific methodology into scalable, reproducible, and audit-ready infrastructure.By: Wren DoughertyAsk a coding agent ...

We analyzed attempted fraud rates and customer abuse patterns on Stripe over the past year and found that AI companies faced 4.3x more fraud attempts than startups overall in Q3 2025. ...

Authors: Bowen Zhou | Staff Software Engineer; Shan Gao | Senior Software Engineer; Jingwen Hu | Software Engineer II; Wenjiang Chu | Staff Software EngineerThe Billion-Embedding ChallengeAt Pinterest...

Lei Pan | Senior Software Engineer; Salina Wu | Senior Software Engineer; Cristian Lopez | Software Engineer I; Guangtong Bai | Staff Software Engineer; Soam Acharya | Principal Engineer; Saurabh Vish...

Clearing the confusion about what Bayesian A/B testing is. The post Why Spotify Is Not Using Bayesian A/B Testing appeared first on Spotify Engineering. ...

Most of what an AI coding agent does for me isn't thinking. It's I/O. The post Portal by Spotify cut my Claude Code token usage by 90% appeared first on Spotify Engineering. ...

Tilman Drerup, Moe Moazzami, Shih-Ting Lin, Greg Reda (and many more)IntroductionAt Instacart, artificial intelligence is fundamentally changing the way our machine learning engineers operate. In a pr...

We’re introducing ZGateway, the proxy we are using to unify traffic through ZippyDB, Meta’s most widely-used key value store. As a bonus, it also enables admission control, load balancing, cross-regio...

Why shorter outputs can cost more, and how GitHub Copilot reduces wasted work across the complete coding task. The post How we make AI coding more cost efficient without sacrificing task quality appea...

We’ve built an AI agent that acts as a secondary expert for a given domain, making deep specialist knowledge readily available and preserved for anyone in an organization to access, share, and build u...

John Grass | Sr. Manager, EngineeringA Fundamental TransformationAn AI team is fundamentally more than just a group whose members incorporate AI tools into their existing workflows. The journey to bec...

By Emma Yanyang Kong, Aditya Deshpande, Asad Abbasi, Bowei Yan, David Fagnan, Ashish Rastogi, Dhaval Patel, Ray ZhangIntroductionThe Netflix experience is a journey of discovery. Every visual cue, fro...

Devin Kreuzer | Sr. Machine Learning Engineer; Yichi Wang | Machine Learning Engineer I; Sujan Reddy Ale | Machine Learning Engineer I; Zelun Wang | Sr. Machine Learning Engineer; Hongtao Lin | Sr. Ma...

Project Lighthouse — Part 3: Introducing project-lighthouse-anonymizeThe data in Project Lighthouse is powered by privacy-preserving anonymization code. We’ve put this code into open source, and publi...

We built a plugin for the GitHub Accessibility Scanner to make sure your alt text is actually accessible. Here's how it works. The post Your alt text passes automated checks. That doesn’t mean i...

Training and serving frontier AI models depends on fast, reliable networks that move data between GPUs without wasting compute cycles.  To meet this challenge at scale, Meta designed MetaRoCE – a clea...

MTIA 300 is the first of Meta’s family of in-house training and inference accelerators optimized for training ranking and recommendation models. We’re sharing how MTIA 300’s built-in NIC chiplets allo...

Samuel Yeboah, Francesco Di Chiara and Mingliang LiuToday, Netflix runs two Flink autoscalers. That is exactly one more than we want. We built the first one in-house years ago, when there was no matur...

As AI transforms software economics, the standard revenue playbook is breaking down. Learn how leaders around the world are preparing for agent buyers, updating processes for faster pricing iteration,...

When we retrain, when we rebuild, and when we leave a model alone.By: Harrison KatzA forecast that carries weightThe Forecasting Data Science team at Airbnb produces many of the forecasts the rest of ...

Platforms like DoorDash, Meta, and Deel already enable stablecoin payouts for global workers. We surveyed 2,300 workers in 20 countries to see what's driving stablecoin demand, where the opportunity i...

TL;DR: LLM predictions can stand in for human outcomes in A/B tests, but only by assumption, not by design.... The post When Can LLMs Replace Humans in A/B Tests? appeared first on Spotify Engineering...

Rebuilding login and signup surfaced product insights, not just technical challenges. Here’s how we designed Flexible Authentication at the intersection of product intuition and technical architecture...

WhatsApp is committed to helping people stay safe while protecting the privacy of their messages. As scam tactics evolve — from impersonation to social engineering to AI-generated lures — we’re ...

Enterprise Java developers have a new superpower—drive GitHub Copilot from idiomatic Java code with annotations, virtual threads, and more. The post Using the GitHub Copilot SDK for Java appeared firs...

How and Why Netflix Built a Real-Time Distributed Graph: Part 3 — Querying the graph with gRPC execution APIAuthors: Nilesh Mishra and Ajit KotiThis is the third entry of a multi-part blog series desc...

Instead of one huge, un-reviewable pull request, teach coding agents to decompose work into a clean, ordered stack with GitHub stacked pull requests. The post Turn one giant AI-generated pull request ...

by Aarti Laddha, Richard Diaz-Cool, Rishika Idnani, Venkatesh SelverajNetflix supports a vast and evolving set of features and content types, ranging from 4K streaming and immersive audio to live stre...

How a branch-free loop and byte-space arithmetic let GitHub case-fold every byte of code search at >45 GiB/s on a single core. The post Don’t stop early: Case-folding source code at memory speed...

Authors: Ying Li, Arjun Rao, Shradha SehgalIntroductionRecommendations sit at the heart of the Netflix experience. Our current production models rely on thousands of hand‑crafted features over users, ...

Dependabot keeps your dependencies current, but its defaults can flood your repository with pull requests. Here's how grouping updates, slowing the cadence, and keeping security fixes fast cut the noi...

How Airbnb teams build trustworthy Generative AI products by treating evaluation as a first-class engineering discipline; not an afterthought.Nestled into the lush hillside, this stunning modern retre...

Companies like Spotify need vast quantities of data accessible at low latency for online services and,... The post Indexing the Data Lake for Online Point Queries appeared first on Spotify Engineering...

Part 1 of 2AuthorsPersonalization (Homefeed): Yuke Yan, Chuxi Wang, Andreanne Lemay, Olafur Gudmundsson, Anna Kiyantseva, Krystal Benitez, Jongho Kim, Jiacong He, Rahul Goutam, James Li, Dylan WangUse...

Ammar Ekbote | Senior Software EngineerChan Kim | Senior Software EngineerManaging Infrastructure as Code (IaC) across a massive organization comes with a unique set of security and logistical challen...

How we built a Transformer-based sequence model that encodes years of guest behavior to surface the right listings at the right time.By: Daochen Zha, Chun How Tan, Xin Liu, Bin Xu, Han Zhao, Xiaowei L...

By AI Platform’s Model Runtime team and Inference teamIntroductionMost organizations consume LLMs through hosted APIs. Netflix went further — we run the full stack ourselves, from model deployment thr...

The cost of writing code dropped; the cost of owning it didn't. A framework for deciding which changes are actually cheap in the AI era. The post The cost of saying yes has changed appeared first on T...

Training an LLM is the easy part. The hard part is designing experiments and evaluations that you can trust enough to know whether the new model is actually an improvement.By: Baharak SaberidokhtIntro...

How we built a Slack-native on-call reasoning harness at Instacart that shortens time to first insight, speeds up theory testing, and turns tribal knowledge into reusable infrastructure.Key Contributo...

By Parth Jain, Rakesh Sukumar, Yingwu Zhao, Renzo Sanchez-Silva & Nathan FisherA deep dive into the engineering challenges of building a real-time service dependency map at Netflix scale: from str...

Sergio Camelo, Caitlin Kearns, Matias Cersosimo, and Tilman DrerupAs artificial intelligence increases the velocity of engineering and science teams, experimental throughput is set to become a bottlen...

Benjamin S. KnightScaling Marketplace experiments requires specialized statistical techniques. We examine why standard ordinary least squares regression (OLS) becomes computationally intractable when ...

Authors: Lequn Wang, Jiangwei Pan, and Linas BaltrunasFigure 1. Autoregressive homepage generation. GenPage builds a Netflix homepage one row or entity at a time, each one conditioned on what’s alread...

Sheng Huang | Software Engineer, AI Platform; Pong Eksombatchai | Machine Learning Engineer, Applied Sciences; Saurabh Vishwas Joshi | Software Engineer, AI Platform; Gaurav Arora | Software Engineer,...

Key Contributors: Karuna Ahuja, Marko Avdalovic, Soroush Sobhkhiz, Shrikar Archak, Xiyu Wang, Ji Chao Zhang, Hao YanIntroductionEvery time a user opens Instacart, they see product recommendations: on ...

Key Contributors: Shrikar Archak, Karuna Ahuja, Soroush Sobhkhiz, Marko Avdalovic, Xiyu Wang, JiChao Zhang, Hao Yan, Chris HartleyIntroductionOperating a grocery catalog at Instacart’s scale means man...

Levi Boxell, Tilman Drerup, Alexandr LenkThe Economics Team at Instacart is an applied science team that operates at the intersection of machine learning engineering and economics. Similar to other ap...

TL;DRBackground: Marketing Across Marketplace and StorefrontInstacart operates across two distinct commerce experiences:Instacart Marketplace, our first-party consumer marketplaceStorefront Pro, our w...

Authors: Trey Zhong, Xiyu WangContributors: Joseph Haraldson, Sharad Gupta, Sarah LamacchiaIntroductionCarrot Ads is Instacart’s omnichannel retail media solution that allows retailer partners to buil...

Key Contributors: Moein Hasani, Hamidreza Shahidi, Trace Levinson, Guanghua ShuIntroductionAt Instacart, we are laser-focused on improving the user experience by making shopping feel easy, engaging, a...