Building a CDN from Scratch: Lessons Learned

On paper, building your own CDN sounds like control and cost savings. In practice it is a long list of hard problems: peering agreements, cache consistency, TLS at scale, and debugging latency that only appears in Johannesburg at 3 a.m. We went down that path so you don't have to. Here's the honest rundown of what it takes to stand up a CDN, what surprised us, and why UploadBird bundles an edge network for you.

The architecture you actually need

A "hello world" CDN is just a couple of POPs and a cache. A production CDN for uploads, images, video, and documents needs much more:

• Global edge presence: enough points of presence to be within ~50 ms of most users.
• Peering and routing: good POPs are useless without the right transit and peering to reduce last-mile latency.
• Cache key discipline: consistent hashing, query-string normalization, and versioned URLs to avoid stale or duplicated objects.
• Invalidation strategy: fine-grained purges that don't require full-cache wipes and won't explode your bill.
• TLS and certificates: automate issuance, rotation, and OCSP stapling across hundreds of thousands of edge nodes.
• Observability: request logs, cache hit ratios, edge RTTs, and health probes you can trust.

The hidden operational cost

Even with a strong SRE team, we spent weeks hunting elusive problems:

• Packet loss localized to a single ISP that only impacted 4% of traffic.
• Edge cache stampedes after heavy invalidations because of poorly scoped cache keys.
• Surprise bills from overly broad purge APIs and misconfigured TTLs.
• Certificate renewals that behaved differently per region due to rate limits and CA quirks.

Why most teams shouldn't DIY

Unless your core business is running an edge network, building a CDN pulls senior engineers away from product work, introduces 24/7 on-call noise, and adds another surface for security incidents. Meanwhile, image optimization, video streaming, and signed URLs are still waiting on top of that foundation.

UploadBird's opinionated alternative

UploadBird ships with a battle-tested CDN baked in:

• 325k+ edge nodes across 135 countries, peered for low latency.
• Immutable, content-hashed paths to avoid heavy invalidations.
• Automatic image and video optimization with modern formats and adaptive bitrate streaming.
• Signed URLs and private files by default.
• Logs, metrics, and status built for developers—not hidden behind CSV exports.

You get the performance and reliability of a mature CDN without owning the operational burden. Point your uploads at UploadBird and focus on the product experience instead of edge math.