# How GitHub Actually Migrated 100 Million Repos to a New Storage Engine

Page: https://stenobird.com/podcast/the-cto-podcast-with-fexingo-technical-leadership-architecture-and-engineering-org-7871807/how-github-actually-migrated-100-million-repos-to-a-new-storage-engine
Text version: https://stenobird.com/podcast/the-cto-podcast-with-fexingo-technical-leadership-architecture-and-engineering-org-7871807/how-github-actually-migrated-100-million-repos-to-a-new-storage-engine.md
Podcast: [The CTO Podcast with Fexingo: Technical Leadership, Architecture, and Engineering Org](https://stenobird.com/podcast/the-cto-podcast-with-fexingo-technical-leadership-architecture-and-engineering-org-7871807)
Published: 2026-06-21T19:54:36+00:00
Episode link: https://audio.fexingo.com/business/the-cto-podcast/episode-0065.mp3
Audio file: https://audio.fexingo.com/business/the-cto-podcast/episode-0065.mp3
Processing state: not_requested
JSON: https://stenobird.com/v1/public/podcasts/the-cto-podcast-with-fexingo-technical-leadership-architecture-and-engineering-org-7871807/episodes/how-github-actually-migrated-100-million-repos-to-a-new-storage-engine
Duration seconds: 565

## Resource

In 2024, GitHub faced an impossible problem: its 15-year-old storage backend, built on bare Git repositories, couldn't keep up with 100 million active repos, AI-generated commits, and terabyte-scale monorepos. This episode drills into how GitHub's engineering team designed and rolled out a custom storage engine called 'GitHub Storage Service' (GSS) without a single user-facing outage. We cover the fundamental shift from POSIX filesystem assumptions to object-storage-native Git, the two-year phased migration that touched every push and clone request, and the surprising performance win: 40% faster clone times for large repos. Lucas and Luna also discuss the trade-off between backward compatibility and architectural purity — and why GitHub chose to keep the Git protocol unchanged even as they ripped out the entire storage layer underneath. #GitHub #StorageEngine #Git #Infrastructure #Migration #ObjectStorage #Engineering #CTO #TechnicalLeadership #Architecture #Scalability #Monorepo #AI #BackwardCompatibility #Performance #Business #FexingoBusiness #BusinessPodcast Keep every episode free: buymeacoffee.com/fexingo

## Actions

- request_transcript: `POST https://stenobird.com/v1/public/podcasts/the-cto-podcast-with-fexingo-technical-leadership-architecture-and-engineering-org-7871807/episodes/how-github-actually-migrated-100-million-repos-to-a-new-storage-engine/transcription-requests` — Idempotently request low-priority transcript generation for this episode.
- read_markdown: `GET https://stenobird.com/podcast/the-cto-podcast-with-fexingo-technical-leadership-architecture-and-engineering-org-7871807/how-github-actually-migrated-100-million-repos-to-a-new-storage-engine.md` — Read the agent-friendly Markdown representation of this episode resource.

A page view does not enqueue transcription. Agents should invoke `request_transcript` explicitly when they need this episode processed.

## Transcript

Full transcripts are not published on public pages unless there is a clear rights basis.