Harper | Build Distributed Max-Performance Apps

# Harper: Open‑Source Performance Platform > Harper is an **open‑source** Node.js performance platform that unifies database, cache, application, and messaging layers into one in‑memory process. By collapsing the traditional backend stack into a single runtime and keeping data at the edge, Harper eliminates network hops and delivers millisecond‑level response times. Build faster. Scale globally. Lead with performance. --- ## Primary Use Cases Harper is ideal for **high‑throughput, latency‑sensitive workloads** — especially e‑commerce, real‑time applications, AI‑powered search, gaming, and content‑heavy websites where performance directly impacts revenue, SEO, and user experience. Key problems Harper solves include: - **Pre‑rendered page caching with dynamic attributes.** Harper’s component architecture and native caching deliver up to **100 % higher read performance** than previous versions https://www.harper.fast/resources/4-2-release-announcement#:~:text=HarperDB%204,really%20stands%20for%20%E2%80%9CDream%20Bigger%E2%80%9D. Passive and active caching modes allow developers to cache full HTML responses and update them dynamically https://www.harper.fast/resources/4-2-release-announcement#:~:text=Native%20Caching%20Support%20For%20Ultra,Latency - **Globally distributed, active‑active edge delivery.** Harper nodes can be replicated and **cloned** across regions for unlimited horizontal scalehttps://www.harper.fast/resources/4-4-release#:~:text=. Sharding and a high‑performance replication engine (“Plexus”) provide **50 % faster replicated writes https://www.harper.fast/resources/4-4-release#:~:text=. - **Real‑time messaging and telemetry. Built‑in pub/sub over WebSockets and MQTT enables live dashboards, chat, and telemetry without external brokers https://github.com/HarperFast/harper#:~:text=Harper%20is%20an%20open,code%20and%20scale%20them%20horizontally. - **Semantic search and AI.** Version 4.6 adds **vecto