I built a fast crypto pricing API as a solo SaaS - here's what I learned about performance as a selling point
We've been building Luzia - a real-time crypto pricing API for developers building trading bots, portfolio trackers, and DeFi apps.
The market already has CoinGecko, CoinMarketCap, CoinAPI, and dozens of others.
So why build another one? 🤔
Because they're all slow. Seriously. Most aggregators add 300-600ms of latency on top of exchange data. For a portfolio dashboard that's fine. For a trading bot making 100 calls per cycle, that's the difference between a 50-second loop and an 8-second loop.
I made speed the core differentiator. Luzia responds in 80-100ms - on a TypeScript stack running on Bun. No Go, no Rust, no exotic infrastructure. Just careful architecture.
I wrote up the engineering decisions behind it: WebSocket-first data ingestion, multi-level caching, atomic rate limiting, read/write separation. Nothing groundbreaking individually, but the combination gets us within striking distance of direct exchange API speeds while aggregating five exchanges through one endpoint.
A few takeaways for other indie builders:
Performance can be a moat. Most SaaS competes on features. Competing on speed is harder to copy because it's an architectural choice, not a checkbox.
Bun is production-ready. I was skeptical but it handles thousands of concurrent WebSocket connections and request throughput without issues. Saved me from maintaining two codebases.
"Fast" is easy to demo. When a prospect runs one API call and sees the response time, the pitch is done. No slide deck needed.
Blog post with the full technical breakdown: https://luzia.dev/blog/fast-crypto-api-engineering
Would love to hear from others building developer tools as a solo founder. How do you think about differentiation when the market already has incumbents?
