# Building personal software with Claude

DevFeed: [Building personal software with Claude](<https://devfeed.tech/articles/building-personal-software-with-claude-21955.md>)

Original publisher: [Read original article](<https://blog.nelhage.com/post/personal-software-with-claude/>)

Author: Nelson Elhage

Published: 2025-01-27T20:00:00Z

Content type: article

Language: en

Sources: [Nelson Elhage](<https://devfeed.tech/sources/nelson-elhage.md>)

Topics: [Claude](<https://devfeed.tech/topics/claude.md>), [Rust](<https://devfeed.tech/topics/rust.md>), [Emacs](<https://devfeed.tech/topics/emacs.md>), [Obsidian](<https://devfeed.tech/topics/obsidian-md.md>), [Software Engineering](<https://devfeed.tech/topics/software-engineering.md>), [JSON](<https://devfeed.tech/topics/json.md>), [Markdown](<https://devfeed.tech/topics/markdown.md>), [Org mode](<https://devfeed.tech/topics/orgmode.md>)

Tags: [app](<https://devfeed.tech/tags/app.md>), [claude](<https://devfeed.tech/tags/claude.md>), [code](<https://devfeed.tech/tags/code.md>), [emacs](<https://devfeed.tech/tags/emacs.md>), [json](<https://devfeed.tech/tags/json.md>), [markdown](<https://devfeed.tech/tags/markdown.md>), [profiling](<https://devfeed.tech/tags/profiling.md>), [rust](<https://devfeed.tech/tags/rust.md>), [software](<https://devfeed.tech/tags/software.md>)

## AI overview

The author describes using Claude, under supervision, to port parts of an Emacs package from Elisp to Rust. The resulting approach reduced one measured execution time from about 90 seconds to 15 milliseconds and changed the author's view of LLMs' role in software engineering.

## Source excerpt

Earlier this month, I used Claude to port (parts of) an Emacs package into Rust, shrinking the execution time by a factor of 1000 or more (in one concrete case: from 90s to about 15ms). This is a variety of yak-shave that I do somewhat routinely, both professionally and in service of my personal computing environment. However, this time, Claude was able to execute substantially the entire project under my supervision without me writing almost-any lines of code, speeding up the project substantially compared to doing it by hand.