# agentsite-static-version=4fe2775b-f8ce-458a-a024-3303fdd80eea
# blacksmith.sh

> AI-optimized mirror of blacksmith.sh containing 53 pages totalling 52,099 words of clean markdown content, structured data, and semantic HTML. Original source: https://blacksmith.sh. Last updated: 2026-10-27T14:24:26.484Z.

Each page is available as HTML (with JSON-LD structured data) and Markdown (text-only, ideal for LLMs and RAG).

## Homepage

- [The Fastest Way to Run GitHub Actions | Blacksmith](/content/site-root.html): Speed up your GitHub actions with Blacksmith. Run CI/CD 2x faster, download caches 4x faster, build Docker images 40x faster, and eliminate queue times. Start free today. (380 words)

## Articles & Blog Posts

- [How to run Jest tests faster in GitHub Actions | Blacksmith](/content/blog/how-to-run-jest-tests-faster-in-github-actions/index.html): Cut 20-minute Jest tests to under 3 minutes by scaling vertically with more cores or horizontally with sharding, with sharding being both faster and cheaper. (992 words)
- [Protect prod, cut costs: concurrency in GitHub Actions | Blacksmith](/content/blog/protect-prod-cut-costs-concurrency-in-github-actions.html): Use GitHub Actions concurrency groups to cancel outdated jobs and prevent deployment conflicts while saving money. (517 words)
- [Faster Docker builds using a remote BuildKit instance | Blacksmith](/content/blog/faster-docker-builds-using-a-remote-buildkit-instance.html): Offload builds to beefy EC2 instances running remote BuildKit with shared cache to drop 30-minute builds to under 2 minutes. (1,346 words)
- [Cache is King: A guide for Docker layer caching in GitHub Actions | Blacksmith](/content/blog/cache-is-king-a-guide-for-docker-layer-caching-in-github-actions.html): Enable Docker layer caching with cache-from and cache-to using GitHub's cache or registry cache for faster CI builds. (1,504 words)
- [How to optimize your Dockerfile for faster Docker builds | Blacksmith](/content/blog/how-to-optimize-dockerfile-faster-docker-builds/index.html): Structure Dockerfiles from least to most frequently changing, copy dependencies before code, and use multi-stage builds. (1,564 words)
- [Push, Cache, Repeat: Amazon ECR as a remote Docker cache for GitHub Actions | Blacksmith](/content/blog/push-cache-repeat-amazon-ecr-as-a-remote-docker-cache-for-github-actions.html): Caching Docker builds in ephemeral CI is tricky, so we showed a customer how to store build cache layers remotely in AWS ECR. Using Docker Buildx with cache-from/cache-to parameters, you can dramatically speed up builds. We saw rebuild times drop from minutes to seconds while keeping GitHub Actions runners efficient. (745 words)
- [Understanding Multi-Stage Docker Builds | Blacksmith](/content/blog/understanding-multi-stage-docker-builds/index.html): Optimize your Docker images with multi-stage builds, a powerful feature that separates build and runtime environments for smaller, more secure, and faster-to-build images. Learn how to leverage multi-stage builds effectively and understand the anatomy of a multi-stage Dockerfile. (1,890 words)
- [Matrix Builds with GitHub Actions | Blacksmith](/content/blog/matrix-builds-with-github-actions/index.html): Run jobs in parallel across multiple configurations (OS, languages, databases, etc.) to catch compatibility issues faster while eliminating redundant workflows and dramatically reducing CI time. (2,139 words)
- [A Guide to Disk Space Management with Docker: How to Clear Your Cache | Blacksmith](/content/blog/a-guide-to-disk-space-management-with-docker-how-to-clear-your-cache.html): Docker devours disk space through images, containers, volumes, and build cache. Fight back with docker system prune and prevent future bloat through .dockerignore files, specific image tags, and regular cleanup habits. (947 words)
- [Docker Architecture: The components and processes - Part 2 | Blacksmith](/content/blog/docker-architecture-the-components-and-processes-part-2.html): Secure your Docker environment with rootless mode, TLS/mTLS encryption, user namespace remapping, container runtime security measures, and comprehensive monitoring using Prometheus/Grafana with proper logging strategies. (1,860 words)
- [Docker Architecture: The components and processes - Part 1 | Blacksmith](/content/blog/docker-architecture-the-components-and-processes-part-1.html): Learn how the Docker daemon handles image pulls, container creation, networks, and volumes behind the scenes. (600 words)
- [How Celery made their GitHub Actions 4x faster and stopped waiting 4-hours on PRs with Blacksmith](/content/customer-stories/celery/index.html): Now, through our new Open Source Sponsorship Program, Celery’s maintainers can commit code in minutes instead of hours, without worrying about unreliable infrastructure causing flaky tests or limits on the number of jobs they can run in parallel. (1,081 words)
- [How Highbeam sped up their GitHub Actions by 2x from 30 to 15 minutes with Blacksmith](/content/customer-stories/highbeam/index.html): Now, Highbeam’s engineers can cost-effectively run their CI/CD pipeline without trading off performance. (709 words)
- [How Upbound merges and ships code faster by speeding up their GitHub Actions with Blacksmith](/content/customer-stories/upbound/index.html): Now, Upbound’s engineering team has shaved critical time off of their Mean Time To Merge allowing engineers to be more productive. (895 words)
- [How to reduce spend in GitHub Actions | Blacksmith](/content/blog/how-to-reduce-spend-in-github-actions/index.html): Group small jobs, cancel redundant runs, cache aggressively, and switch to faster runners like Blacksmith to slash CI costs by 70%. (1,052 words)
- [Why I joined Blacksmith to work on storage again | Blacksmith](/content/blog/why-i-joined-blacksmith-to-work-on-storage-again/index.html): Why I joined Blacksmith to work on storage again and where off-the-shelf storage runs out (3,566 words)
- [How Chroma deploys 2x faster while cutting GitHub Actions costs by 50% with Blacksmith](/content/customer-stories/chroma/index.html): Now, Chroma’s engineering team can run tests for every PR in half the time, with stable caching and significantly reduced CI costs — enabling faster, more frequent deployments. (142 words)
- [Best Practices for Managing Secrets in GitHub Actions | Blacksmith](/content/blog/best-practices-for-managing-secrets-in-github-actions.html): Rotate GitHub Actions secrets regularly (30-90 days), use OIDC over long-lived tokens, implement environment-based access controls with approval workflows, avoid hardcoded secrets, and use descriptive naming conventions, or supply chain attackers will own your deployment pipeline. (490 words)
- [How we built a logging platform for GitHub Actions with ClickHouse | Blacksmith](/content/blog/logging/index.html): When it comes to observability in CI, logs are still the main tool in a developer’s toolbox. Yet, the experience still sucks in GitHub Actions — until now. (1,292 words)
- [How Clerk reduced test flakiness and cut GitHub Actions costs by 70% with Blacksmith](/content/customer-stories/clerk/index.html): Now, Clerk’s developers can reliably and efficiently run their integration tests before publishing to tens of thousands of developers, without dealing with flakiness caused by the underlying infrastructure. (605 words)
- [The physics of Docker build caching | Blacksmith](/content/blog/the-physics-of-docker-build-caching/index.html): Concepts, rules of thumb, and what dissecting a few hundred CI builds says about them. (3,067 words)
- [Why Finch ditched self-hosting GitHub Actions runners on Kubernetes for Blacksmith](/content/customer-stories/finch/index.html): Now, Finch’s DevOps team can reliably and cost-effectively run their CI/CD pipelines without the subtly hidden operational costs of self-hosting. (711 words)
- [Code mode lost its first race. Then we gave it muscle memory | Blacksmith](/content/blog/code-smith-code-mode/index.html): Speed up your GitHub actions with Blacksmith. Run CI/CD 2x faster, download caches 4x faster, build Docker images 40x faster, and eliminate queue times. Start free today. (1,531 words)
- [Reverse engineering GitHub Actions cache to make it fast | Blacksmith](/content/blog/cache/index.html): We reverse engineered GitHub Actions cache internals to transparently route cache requests through our faster, colocated cache. This delivered up to 10x faster cache performance for some of our customers, with no code changes required and no need to maintain forks of upstream actions. (1,377 words)
- [Blacksmith outage on July 21, 2026 | Blacksmith](/content/blog/blacksmith-outage-on-july-21-2026/index.html): Speed up your GitHub actions with Blacksmith. Run CI/CD 2x faster, download caches 4x faster, build Docker images 40x faster, and eliminate queue times. Start free today. (1,225 words)
- [Why we chose not to look like every other company in Silicon Valley | Blacksmith](/content/blog/rebrand/index.html): The first thing investors, talent, and consumers see isn’t your product — it’s your brand. (568 words)
- [How we SSH into GitHub Actions | Blacksmith](/content/blog/ssh/index.html): We built an SSH feature to let you pop the hood on running CI jobs. It relies on three subsystems — network tunneling, DNS registration, and SSH key management — each handling quirks in the VM lifecycle. (1,159 words)
- [Building Multi-Platform Docker Images for ARM64 in GitHub Actions | Blacksmith](/content/blog/building-multi-platform-docker-images-for-arm64-in-github-actions.html): Use native ARM64 runners instead of slow QEMU emulation for faster builds and lower costs. (1,013 words)
- [What is your CI job talking to? | Blacksmith](/content/blog/what-is-your-ci-job-talking-to/index.html): How we built line-rate network observability for untrusted CI jobs without touching the guest. (2,638 words)
- [The GitHub Actions control plane is no longer free | Blacksmith](/content/blog/actions-pricing/index.html): GitHub is adding a $0.002-per-minute fee on all GitHub Actions usage, so the control plane is no longer free. (629 words)
- [Closed-loop development: how we shipped Mac runners in 3 weeks | Blacksmith](/content/blog/how-we-shipped-mac-runners-in-3-weeks/index.html): We built the fastest Mac runners, fast - in less than three weeks by leveraging closed-loop development with agents. (1,171 words)
- [How Blacksmith survives ISP degradation with Tailscale Services | Blacksmith](/content/blog/blacksmith-x-tailscale/index.html): A transparent GitHub proxy, leveraging Tailscale Services and Squid, was built to overcome ISP degradation that was causing GitHub Actions jobs to fail. This internal solution reroutes GitHub traffic through a stable, alternate network path, providing defense-in-depth for runners with zero changes required from customers. (955 words)
- [Announcing Blacksmith’s Series B led by Peak XV Partners | Blacksmith](/content/blog/announcing-blacksmiths-series-b-led-by-peak-xv-partners.html): We raised a $45M Series B led by Peak XV. With AI codegen tools, developers are writing more code than ever. We’re building the infrastructure to validate it. (570 words)
- [US west region outage due to facility cooling loss on August 13, 2026 | Blacksmith](/content/blog/us-west-regional-failure-august-13-2026-postmortem/index.html): US west region outage due to facility cooling loss on August 13, 2026 (988 words)
- [Does a coding agent need a face? | Blacksmith](/content/blog/does-a-coding-agent-need-a-face/index.html): We designed an agent with a face for [code]smith, brought it to life, and made room for some fun personality in a product that takes performance really seriously. (1,050 words)
- [How the economics of multitenancy work | Blacksmith](/content/blog/the-economics-of-operating-a-ci-cloud/index.html): CI is chaotic, bursty, spiky, and short-lived. That chaos is a nightmare unless you’re built for it. Blacksmith’s serverless CI cloud thrives on unpredictability: more customers = more noise = smoother utilization = lower costs for everyone. Multitenancy isn’t just efficient — it’s profitable. And yes, the margins are good. (1,448 words)
- [How VEED deploys 2x faster while cutting GitHub Actions costs by 70% with Blacksmith](/content/customer-stories/veed/index.html): Now, VEED’s engineers have cut their CI times in half and their costs by 70%, which has been an insane productivity boost for the whole team. (841 words)
- [How Ashby slashed GitHub Actions costs by 75% and doubled deployment frequency with Blacksmith](/content/customer-stories/ashby/index.html): Now, Ashby’s developers can reliably and efficiently run their tests for every git push and continuously deploy to their more than 2500 customers without having to slow down. (812 words)
- [How Mintlify made their GitHub Actions and Docker Builds 2x faster with Blacksmith](/content/customer-stories/mintlify/index.html): Now, Mintlify’s developers can continue to tear down and replace all the existing documentation out there in the world — twice as fast. (543 words)
- [Contact Our Team](/content/contact-our-team/index.html): Get in touch with our team. Book a demo to learn how Blacksmith can save you time and money. (25 words)
- [Blacksmith Support | GitHub Actions Help & Documentation](/content/support/index.html): Get help with Blacksmith’s CI/CD platform. Access GitHub Actions documentation, performance guides, and technical support to keep your CI/CD pipelines fast and reliable. (141 words)
- [Careers - Change How Software Gets Built | Blacksmith](/content/careers/index.html): Blacksmith is fast CI. We are building a high-performance cloud platform with a hardware-software stack purpose-built for CI. (325 words)
- [How Blacksmith runs >10M jobs per day | Blacksmith](/content/blog/how-blacksmith-runs-10-million-jobs-per-day/index.html): Scaling Scheduling past 10 Million Daily Jobs, Follow a VM demand through Blacksmith’s assigner and agent protocol: durable queues, independent fleet views, leader failover, and start receipts. (842 words)
- [About Blacksmith | Making GitHub Actions Fast](/content/company/index.html): Meet the team behind Blacksmith. Learn how we’re redefining CI/CD performance with a mission to make GitHub Actions faster and more efficient for every developer. (454 words)
- [Secure GitHub Actions | Blacksmith](/content/security/index.html): Run GitHub actions securely with Blacksmith. SOC 2 and GDPR compliant with advance security controls for reliable, fast CI/CD at any scale. (1,038 words)
- [Self-hosting CI gets harder every month | Blacksmith](/content/self-hosting/index.html): Across 315 organizations, CI jobs grew 7.5x from January 2025 to September 2026 while active developers grew 1.7x. See when managed GitHub Actions runners beat self-hosting. (850 words)
- [Blacksmith Guides | Faster GitHub Actions, Docker Builds, and CI/CD](/content/guides/index.html): Learn best practices for fast GitHub Actions, Docker builds, caching, and DevOps with Blacksmith’s guides. (185 words)
- [The two faces of tomorrow | Blacksmith](/content/blog/tomorrow/index.html): We’ve closed our $10 million Series A, led by Google Ventures. (440 words)
- [Pricing](/content/pricing/index.html): Start for free with plans to help any business speed up their GitHub Actions, save time, and reduce CI/CD costs by up to 75%. (328 words)
- [GitHub Actions Success Stories - Case Studies | Blacksmith](/content/customers/index.html): See how engineering teams speed up their GitHub Actions with Blacksmith. Real case studies showing 2x faster GitHub Actions, 70% cost reductions, and better developer productivity. (273 words)
- [Building the CI cloud: our Series C | Blacksmith](/content/blog/series-c/index.html): Sequoia is leading our Series C at a $1B valuation to scale the CI cloud. (408 words)
- [Blacksmith Blog | Engineering Blog for Fast GitHub Actions](/content/blog/index.html): Find Blacksmith engineering, product, and news articles to help DevOps teams and founders work faster with GitHub Actions. (178 words)

## Resources

- [Full Page Index](/index.html): Browse all cached pages with rich metadata
- [About This Cache](/about.html): Methodology, technical details, and usage guidelines
- [XML Sitemap](/sitemap.xml): Machine-readable sitemap for crawler discovery
- [Robots.txt](/robots.txt): Crawler directives
- [Agentsite Network](https://agentsite.network/network.html): Public index of Agentsites and their machine-readable resources