TLDR: I launched Requiems API, grab code REQUIEMSLAUNCH for 50% off and try it at requiems.xyz

Hey everyone,

I've been a backend engineer for 6 years, mostly as an employee shipping things for other people's businesses. This is the first time I've built and launched something of my own, handling everything myself: deployment, infrastructure, billing, config across multiple platforms, the whole thing. It was a grind but honestly one of the best things I've done for my own growth as an engineer.

I've always loved API platforms. When I was first learning to code I kept using these sites that gave you a single key and a whole collection of endpoints. I always thought it'd be cool to build one. Six months ago I actually started. Today I'm launching it.

What is Requiems API?

One API key, one dashboard, access to dozens of endpoints across finance, validation, AI, and more. The idea is that you're building something and you need a handful of small utility APIs. Instead of juggling multiple accounts and keys, you get it all from one place.

Finance and Validation (what I'm most proud of)

The finance category has things like BIN lookup for card validation, IBAN and SWIFT/BIC validation, live exchange rates and crypto prices, commodity prices, a mortgage calculator, and historical inflation data by country.

On the validation side there's full email validation (syntax, DNS, reachability), disposable email detection, email normalization, phone number validation with carrier and region info, WHOIS lookup, MX records, and domain info.

Everything else

Beyond those two there's also: IP intelligence with VPN/proxy detection, user agent parsing, QR and barcode generation, password generation, timezone and geocoding lookups, public holidays and working days by country, language detection, sentiment analysis, text similarity, lorem ipsum, thesaurus, spellcheck, profanity detection, and a handful of other utilities.

How it's built

Multi-language monorepo. Go handles all the business logic and talks to Postgres. Rails handles the dashboard, user auth, subscriptions, and background jobs. Two Cloudflare Workers sit in front: one is the public-facing auth gateway that validates keys at the edge and proxies requests to Go, and the other is an internal management service for key CRUD and usage analytics. Cloudflare KV and D1 handle edge-side auth caching and usage recording so the main DB doesn't get hit on every request.

Probably over-engineered for v1, but I learned a lot doing it this way.

Launch promos

50% off: REQUIEMSLAUNCH valid all month!!

100% promo code: If you make a post or video about Requiems API that hits 10,000+ views (or 1000+ views for video), DM me the link and I'll send you a full discount code.

The video or post doesn’t have to focus entirely on Requiems API. You could create something like a tutorial on building a login/signup flow and use the validation endpoints as a practical example of how to integrate Requiems API into different types of applications.

This is the biggest thing I've built on my own. I know it's not perfect. If something is broken, confusing, slow, or the docs are unclear, please tell me. I would rather you roast me in the comments than leave without saying anything.

Every comment gets read. Thanks for reading. 🙏