We’re sharing insights into Meta’s Capacity Efficiency Program, where we’ve built an AI agent platform that helps automate finding and fixing performance issues throughout our infrastructure. By leveraging encoded domain expertise across a unified, standardized tool interface these agents help save power and free up engineers’ time away from addressing performance issues to innovating on [...] Read More... The post…
#devinfra
24 posts
16 Apr
9 Apr
At Meta, WebRTC powers real-time audio and video across various platforms. But forking a large open-source project like WebRTC within our monorepo presents unique challenges – over time, an internal fork can drift behind upstream, cutting itself off from community upgrades. We’re sharing how we escaped this “forking trap” – from building a dual-stack architecture [...] Read More... The post…
8 Apr
As AI increases developer speed and productivity it also increases the need for safeguards. On this episode of the Meta Tech Podcast, Pascal Hartig sits down with Ishwari and Joe from Meta’s Configurations team to discuss how Meta makes config rollouts safe at scale. Listen in to learn about canarying and progressive rollouts, the health checks [...] Read More... The…
6 Apr
AI coding assistants are powerful but only as good as their understanding of your codebase. When we pointed AI agents at one of Meta’s large-scale data processing pipelines – spanning four repositories, three languages, and over 4,100 files – we quickly found that they weren’t making useful edits quickly enough. We fixed this by building [...] Read More... The post…
2 Apr
This is the second post in the Ranking Engineer Agent blog series exploring the autonomous AI capabilities accelerating Meta’s Ads Ranking innovation. The previous post introduced Ranking Engineer Agent’s ML exploration capability, which autonomously designs, executes, and analyzes ranking model experiments. This post covers how to optimize the low-level infrastructure that makes those models run [...] Read More... The post…
17 Mar
Ranking Engineer Agent (REA): The Autonomous AI Agent Accelerating Meta’s Ads Ranking Innovation
FacebookMeta’s Ranking Engineer Agent (REA) autonomously executes key steps across the end-to-end machine learning (ML) lifecycle for ads ranking models. This post covers REA’s ML experimentation capabilities: autonomously generating hypotheses, launching training jobs, debugging failures, and iterating on results. Future posts will cover additional REA capabilities. REA reduces the need for manual intervention. It manages [...] Read More... The post…
11 Feb
The Death of Traditional Testing: Agentic Development Broke a 50-Year-Old Field, JiTTesting Can Revive It
FacebookWHAT IT IS The rise of agentic software development means code is being written, reviewed, and shipped faster than ever before across the entire industry. It also means that testing frameworks need to evolve for this rapidly changing landscape. Faster development demands faster testing that can catch bugs as they land in a codebase, without [...] Read More... The post…
22 Dec 2025
The 2025 Typed Python Survey, conducted by contributors from JetBrains, Meta, and the broader Python typing community, offers a comprehensive look at the current state of Python’s type system and developer tooling. With 1,241 responses (a 15% increase from last year), the survey captures the evolving sentiment, challenges, and opportunities around Python typing in the [...] Read More... The post…
16 Oct 2025
Sapling is a scalable, user-friendly, and open-source source control system that powers Meta’s monorepo. As discussed at the GitMerge 2024 conference session on branching, designing and implementing branching workflows for large monorepos is a challenging problem with multiple tradeoffs between scalability and the developer experience. After the conference, we designed, implemented, and open sourced our [...] Read More... The post…
14 Oct 2025
At Open Compute Project Summit (OCP) 2025, we’re sharing details about the direction of next-generation network fabrics for our AI training clusters. We’ve expanded our network hardware portfolio and are contributing new disaggregated network platforms to OCP. We look forward to continued collaboration with OCP to open designs for racks, servers, storage boxes, and motherboards [...] Read More... The post…
6 Oct 2025
OpenZL is a new open source data compression framework that offers lossless compression for structured data. OpenZL is designed to offer the performance of a format-specific compressor with the easy maintenance of a single executable binary. You can get started with OpenZL today by visiting our Quick Start guide and the OpenZL GitHub repository. Learn more [...] Read More... The…
29 Sept 2025
Over the past 21 years, Meta has grown exponentially from a small social network connecting a few thousand people in a handful of universities in the U.S. into several apps and novel hardware products that serve over 3.4 billion people throughout the world. Our infrastructure has evolved significantly over the years, growing from a [...] Read More... The post Meta’s…
11 Aug 2025
Federation Platform and Privacy Waves: How Meta distributes compliance-related tasks at scale
FacebookWe’re exploring Meta’s Federation Platform, a scalable set of tools for managing compliance-related tasks, along with Privacy Waves, our method for batching these tasks and ensuring accountability. Together, the Federation Platform and Privacy Waves create a structured, effective, and sustainable approach to operationalizing privacy work, enabling Meta to safeguard user data for the billions of [...] Read More... The post…
6 Aug 2025
The state of the research Diff Risk Score (DRS) is an AI-powered technology built at Meta that predicts the likelihood of a code change causing a production incident, also known as a SEV. Built on a fine-tuned Llama LLM, DRS evaluates code changes and metadata to produce a risk score and highlight potentially risky code [...] Read More... The post…
1 Jul 2025
Have you ever worked is legacy code? Are you curious what it takes to modernize systems at a massive scale? Pascal Hartig is joined on the latest Meta Tech Podcast by Elaine and Buping, two software engineers working on a bold project to rewrite the decades-old C code in one of Meta’s core messaging libraries [...] Read More... The post…
30 Jun 2025
We are proud to announce that Meta has officially joined the Kotlin Foundation as a gold member, marking a significant milestone in our ongoing commitment to Kotlin and the broader Android development ecosystem. Over the past several years, Meta engineers have been actively migrating our extensive Android codebase—comprising tens of millions of lines—from Java to [...] Read More... The post…
20 May 2025
As Meta has launched new, innovative products leveraging generative AI (GenAI), we need to make sure the underlying infrastructure components evolve along with it. Applying infrastructure knowledge and optimizations have allowed us to adapt to changing product requirements, delivering a better product along the way. Ultimately, our infrastructure systems need to balance our need to [...] Read More... The post…
15 May 2025
Back in 2017, engineers at Meta sought to create a type checker for Instagram’s typed Python codebase. Years later, as the type system continued to evolve, that type checker eventually became Pyrefly. Pyrefly is a new type checker and IDE experience for Python, written with Rust, and now available for the entire Python community to [...] Read More... The post…
Today we are announcing an alpha version of Pyrefly, an open source Python type checker and IDE extension crafted in Rust. Pyrefly is a static type checker that analyzes Python code to ensure type consistency and help you catch errors throughout your codebase before your code runs. It also supports IDE integration and CLI usage [...] Read More... The post…
5 May 2025
Meta and Quansight have improved key libraries in the Python Ecosystem. There is plenty more to do and we invite the community to help with our efforts. We’ll look at two key efforts in Python’s packaging ecosystem to make packages faster and easier to use: 🚀 Unlock performance wins for developers through free-threaded Python – [...] Read More... The post…
25 Feb 2025
Meta has been working to shift its Android codebase from Java to Kotlin, a newer language for Android development that offers some key advantages over Java. We’ve even open sourced various examples and utilities we used to in our migration to manipulate Kotlin code. So how do you translate roughly tens of millions of lines of Java [...] Read More...…
24 Jan 2025
Introducing a new Android UI framework like Jetpack Compose into an existing app is more complicated than importing some AARS and coding away. What if your app has specific performance goals to meet? What about existing design components, integrations with navigation, and logging frameworks? On this episode of the Meta Tech Podcast Pascal Hartig is [...] Read More... The post…
16 Jan 2025
Do types actually make developers more productive? Or is it just more typing on the keyboard? To answer that question we’re revisiting Diff Authoring Time (DAT) – how Meta measures how long it takes to submit changes to a codebase. DAT is just one of the ways we measure developer productivity and this latest episode [...] Read More... The post…
19 Dec 2024
We’re sharing details about Glean, Meta’s open source system for collecting, deriving, and working with facts about source code. In this blog post we’ll talk about why a system like Glean is important, explain the rationale for Glean’s design, and run through some of the ways we’re using Glean to supercharge our developer tooling at [...] Read More... The post…