Vercel OG Image Generation 也是做这的。

为了不跑 chromium，他们自己做了个库把 HTML + CSS 转成 SVG 再转 PNG。

看上面 DEMO 效果和性能还行，就是 PNG 和 SVG 结果有点不同。

Shared memory between processes is a common practice in the OpenResty/Nginx world.

Not sure if you protect the shared memory from concurrent access. At least in Nginx, they use a lock for this.