Peter Steinberger

Sources#

• Loop Engineering

Summary#

Austrian developer best known as the founder of PSPDFKit (a widely-licensed PDF SDK) which he built and later exited. Post-exit he became one of the most-followed independent experimenters with AI coding agents (handle @steipete), publishing hands-on workflows and takes on running fleets of agents. He originated the framing that Addy Osmani's Loop Engineering essay is built on.

The framing quote#

"You shouldn't be prompting coding agents anymore. You should be designing loops that prompt your agents."

This is the seed of Loop Engineering — the shift from human-as-prompter to human-as-loop-designer. It maps onto the same realization Boris Cherny reached independently ("my job is to write loops"), and Osmani's enumeration of five product-native primitives is essentially Steinberger's list made concrete against the Codex app and Claude Code.

Connections#

• Loop Engineering — originated the "design loops, don't prompt" thesis the discipline is named for
• Boris Cherny — reached the same loop-design framing from inside Anthropic
• Addy Osmani — gave the framing its name and anatomy
• Agent Loop Pattern — the primitive his framing operates on

Sources#

• Loop Engineering — quoted as the originator of the loop-design framing