Architecture & optimization

The GitHub Ruby on Rails monolith is big: nearly two million lines of code and more than 1,000 engineers collaborating on it, to the tune of around 20 deployments every day. To operate at that scale, while providing a performant and highly available experience to the millions of developers who rely on our platform, we dive deep into software development fundamentals. Follow along to see how we build and continually improve the tools you use every day.

Featured

How we organize and get things done with SERVICEOWNERS

Take CODEOWNERS and GitHub teams to the next level. Learn about how GitHub engineering solves the age old problem of who owns what.

Measuring Git performance with OpenTelemetry

Use our new open source Trace2 receiver component and OpenTelemetry to capture and visualize telemetry from your Git commands.

Optimize your GitHub Codespaces costs with upgraded virtual machines

See how much more you can get out of GitHub Codespaces by taking advantage of the improved processing power and increased headroom in the next generation of virtual machines.

How we build containerized services at GitHub using GitHub

Learn about how we build containerized services that power microservices on the GitHub.com platform and many internal tools.

Latest

Crafting a better, faster code view

The new GitHub Code View brings users many new features to improve the code reading and exploration experiences, and we overcame a number of unique technical hurdles in order to deliver those features without compromising performance.

Building GitHub with Ruby and Rails

Since the beginning, GitHub.com has been a Ruby on Rails monolith. Today, the application is nearly two million lines of code and more than 1,000 engineers collaborate on it daily.…

How GitHub Docs’ new search works

GitHub Docs recently changed its site-search to Elasticsearch. Here’s how it was implemented.

The technology behind GitHub’s new code search

A look at what went into building the world’s largest public code search index.

How we tripled max concurrent jobs to boost performance of GitHub Actions

The GitHub Actions team has done lots of work to improve the performance and resource consumption of Actions on GHES in the past year.

Scaling Git’s garbage collection

A tour of recent work to re-engineer Git’s garbage collection process to scale to our largest and most active repositories.

How we’re using projects to build projects

At GitHub we use GitHub to build our own products, and the new projects experience is no different. Check out how our team uses projects to build powerful project planning for developers.

Improving Git push times through faster server side hooks

The history of pre-receive hooks, how we discovered that the performance was problematic, and how we went about safely replacing them.

Performance at GitHub: deferring stats with rack.after_reply

How we sped up GitHub.com by moving slow, non-critical code into rack.after_reply.

How we use Web Components at GitHub

At GitHub, we pride ourselves on delivering a first-class developer experience. A considerable part of our work is on our front end, which we strive to keep as lightweight, fast,…

How GitHub Actions renders large-scale logs

Rendering logs in a web UI might seem simple: they are just lines of plain text. However, there are a lot of additional features that make them more useful to…

GitHub Mobile and GraphQL

GitHub’s mobile applications have used GraphQL to power new features. We’ve now been able to move faster and get more done with less hassle and no over-fetching. We were able…

Why Write ADRs

How architecture decision records can help your team.

CodeGen: Semantic’s improved language support system

The Semantic Code team shipped a massive improvement to the language support system that powers code navigation. Code navigation features only scratch the surface of possibilities that start to open up when we combine Semantic‘s program analysis potential with GitHub’s scale.