Compiler Explorer Cost Transparency

Summary

Compiler Explorer Cost Transparency Written with LLM assistance.Details at end. I’ve been meaning to do this for ages - a proper breakdown of where all the Patreon, GitHub, Paypal, and commercial sponsorship money goes to keep Compiler Explorer running. TL;DR: we’re spending about $3,100 per month (~$37,000 annually) to serve around 8 million backend compilations monthly. That works out to roughly $0.00039 per compilation - shockingly good value! Taking April 2025 as an example, our costs are split 80% on AWS costs ($2,550) and 20% on operational costs ($550); for a total of $3,100. The operational bit includes monitoring tools (Grafana, Papertrail, Sentry), my share of office costs whilst I’m between “real” jobs, and community expenses like the Discord server and shipping stickers to supporters. Our infrastructure serves peak days of up to 1.66 million requests across x86_64, ARM64, and GPU platforms. We have a pretty impressive uptime for a bunch of amateurs (99.98% uptime in the last 30 days). And we genuinely don’t know who you are or what you’re compiling, which is important to me personally. The traffic patterns are always interesting to look at - we see clear daily cycles with US daytime hours being busiest, weekend dips, and holiday lulls. January 2025 was our peak month at $3,345, showing how much extra it can cost at busier times. Cost Optimisations We’ve done some work to get the most for our money out of AWS (Amazon Web Services, where most of our infrastructure is): Spot instances for the x86 production fleet (60-90% cost savings vs on-demand). Spot instances are ones where we “bid” for otherwise unused AWS resources. Careful scheduling for build infrastructure saves ~$481/month compared to running it 24/7. Single load balancer serving all environments - production, staging, beta, and our sub-environments for GPU and aarch64. EFS lifecycle policies automatically moving old and less frequently-accessed data to cheaper storage. EFS is Amazon’s elastic net...