Blog
Deep technical writing from actually running custom-domain infrastructure at scale — SSL automation, Let's Encrypt rate limits, edge routing, and preventing domain takeover.
Custom Domains: Build vs Buy (TCO Calculator)
An interactive calculator and honest breakdown of what custom-domain infrastructure really costs to build vs buy — per-domain pricing across cnames.dev, Cloudflare, SaaSKevin, Entri, and self-host.
July 6, 2026
Cloudflare for SaaS Pricing: The Real Cost at Scale
What Cloudflare for SaaS actually costs: the $0.10/hostname math after 100 free, the base plan you also pay for, and where it beats or loses to alternatives. Dated July 2026.
July 6, 2026
Entri Pricing Explained (and the Self-Serve Math)
What Entri costs as of July 2026: the $249/mo published entry point, the sales-led higher tiers, and how the per-domain math compares to a self-serve API.
July 5, 2026
Anatomy of a Custom-Domains Proxy
A deep dive into every stage a request passes through in a multi-tenant custom-domains proxy — DNS, SNI, cert selection, host routing, header shaping, and origin fetch.
July 5, 2026
Let's Encrypt Rate Limits at Scale
Which Let's Encrypt rate limits actually bite when you issue certificates for thousands of customer domains, the math behind them, and the mitigations that work.
July 4, 2026
Why We Give You the Real Client IP (and How)
Once you proxy custom domains, your origin sees the proxy IP. Here is how to forward and trust the real client IP with X-Forwarded-For and PROXY protocol — without getting spoofed.
July 3, 2026
How to Add Custom Domains to a Vercel App
Add customer domains to a Vercel project via the Domains API: verification, apex records, wildcard limits, and where Vercel stops. DIY and the one-API-call way.
July 6, 2026
How to Add Custom Domains on Fly.io
Issue certificates for customer domains on Fly.io with fly certs: A/AAAA + _acme-challenge records, shared vs dedicated IPs, and the apex case. DIY and the easy way.
July 5, 2026
Custom Domains and Supabase: What You Actually Need
Two different things get called "Supabase custom domains": your project's vanity API URL, and letting your app's users bring their own domain. How to do each.
July 4, 2026
How to Add Custom Domains to Your Next.js App
Route customer domains in Next.js with middleware and the Host header, forward the real client IP, and issue SSL — the DIY way and the one-API-call way.
July 6, 2026
How to Add Custom Domains to a Node.js / Express App
Handle customer domains in Express: host-based routing, trust proxy for the real client IP, and TLS termination — the DIY way and the one-API-call way.
July 5, 2026
How to Add Custom Domains on Cloudflare Workers
Route customer hostnames in a Cloudflare Worker, the options for SSL (Custom Hostnames vs a proxy), and where each approach breaks. DIY and the one-API-call way.
July 4, 2026
How to Add Custom Domains to Your Rails App
Custom domains in Rails: the config.hosts gotcha that blocks unknown hosts, routing constraints, the real client IP, and SSL. DIY and the one-API-call way.
July 3, 2026
How to Add Custom Domains to Your Laravel App
Custom domains in Laravel: Route::domain constraints, the TrustProxies middleware for real client IPs behind a proxy, and SSL. DIY and the one-API-call way.
July 1, 2026
How to Add Custom Domains to Your Django App
Custom domains in Django: the ALLOWED_HOSTS gotcha, SECURE_PROXY_SSL_HEADER behind a TLS-terminating proxy, host-based tenant routing, and SSL. DIY and the easy way.
June 27, 2026
Custom Domains for SaaS: The Complete Guide (2026)
CNAME vs A records, the apex problem, SSL issuance (HTTP-01 vs DNS-01), SNI, proxy architecture, tenant routing, and how to avoid domain takeover. Written by an operator.
July 6, 2026
How We Run SSL for 5,000+ Customer Domains
The architecture behind 5,000+ customer domains: on-demand TLS, Let's Encrypt rate-limit math, a stateless edge, and the failure modes that actually bite at scale.
July 2, 2026
What Is Domain Connect? One-Click DNS, Explained
Domain Connect lets users configure DNS at GoDaddy, IONOS and others in one click — no copy-pasting records. How the protocol works, and where it falls short.
June 30, 2026
The CNAME-at-Apex Problem, and How to Solve It
You cannot put a CNAME on a root domain. Here is why, what breaks when you try, and the five real fixes: ALIAS/ANAME, apex A records, redirects, and more.
June 24, 2026