artlu's Bear Blog

Please Use My Free Software

if you have 30-100 personal projects, you might benefit from this...

Announcing lmdis, the Lightning Memory-Mapped Dictionary Server. FOSS under MIT license.

tl;dr

What

lmdis is a drop-in replacement for Upstash Redis, preserving the same developer ergonomics. It has all the functionality you might use for daily driving, and gives more headroom than Upstash or Cloudflare's free tiers.

The repo provides 3 things:

The codebase is LLM-friendly for understanding, has great test coverage, and is reasonably hardened for personal use.

Why

Upstash Redis is the fastest, most performant way to bootstrap a KV cache for any web app. It works just as well with Vercel and Cloudflare. They promise to scale with you (and charge you only when you need the scale).

I have too many personal projects on their free plan, and it's fragile for one project with usage to bring all my other projects into a resource constraint.

For personal, non-performance and non-edge-distribution-sensitive projects, one can serve a KV cache on a home server or VPS for marginally zero cost.

When any individual project hits the need to scale vertically or horizontally, it is simple to drop in a paid Upstash Redis service.

How

99.99% of Redis calls are SET or GET.

This service runs on Bun and lmdb for rock-solid simplicity.

Before LLMs, it was not worth the dev time to write this small software. (Upstash is quite cheap, due to their scale.) But now, LLMs enable real abundance for certain kinds of well-understood, resource-lite compute needs.

Addendum

The startup stack used to be Vercel, Supabase Auth, Upstash, Neon Postgres, etc.

You pay via vendor lock-in after you achieve scale.

And it used to be hard / expensive / a distraction to provide reliability.

Technical problems around caching are all solved, or at least, well understood. SaaS and PaaS and IaaS pricing power is based on obscure knowledge, and a bit of capital.