Kieran Klaassen

Kieran Klaassen is general manager of Cora and an entrepreneur in residence at Every, where he developed compound engineering: a way of building software with AI agents that turns each correction, product decision, and completed feature into reusable knowledge. His work tackles a central problem of agent-assisted development: generating code is becoming easier, but preserving judgment about what to build and how it should feel remains difficult.

Before joining Every, Klaassen co-founded Vinebase and Occasion and served as vice president of engineering. At Cora, he has explored a different model: one engineer retaining responsibility for a substantial product, assisted by designers, specialist engineers, and coding agents. The agent-native email client combines Ruby on Rails and React, with functionality accessible to both users and software agents. Every released Cora from beta in 2025; Klaassen subsequently began rebuilding the product around more expansive agent-native capabilities.

As agents improved, the constraints on his work shifted from unreliable code to planning and then to product judgment. Repeatedly supplying the same preferences and corrections led him to build persistent memory into the development process. When a single instructions file became unwieldy, he moved toward repository-based solution documents that preserve not only decisions but their rationale, failed experiments, and postmortems.

• Compound engineering as institutional memory. Klaassen’s engineering framework treats each feature and review as an opportunity to improve future execution. Agents draw on accumulated decisions instead of repeating research or mistakes; he argues that well-targeted context can ultimately reduce token usage by preventing unnecessary correction.

• Human judgment at the boundaries. People define the user problem before agents plan, implement, review, and test; they return afterward to assess whether the result meets the intended standard. For Klaassen, product polish includes qualities automated correctness checks miss, such as visual consistency, responsiveness, and delight.

• The Compound Engineering plugin. The open-source Compound Engineering plugin packages these workflows for coding tools including Claude Code, Codex, and Cursor. Its capabilities extend beyond implementation into brainstorming, document review, prioritization, and capturing lessons; CE Ideate evaluates potential work against existing issues, strategy, and accumulated project knowledge.

• Production-grounded evaluation and feedback. Klaassen’s Leva provides language-model evaluation with production data for Rails applications. Riffrec captures screen activity, spoken feedback, interaction details, network behavior, and console errors so people and agents can investigate concrete product problems.

• Durable context over constant supervision. His folder-based approach to agents organizes instructions and project knowledge into inspectable working context. A post about running coding agents while hiking illustrates the practical ambition: useful autonomous execution without continuous human attention.

Klaassen measures the system against a demanding product standard: shipping a feature should make the next feature easier to build.