Kieran Klaassen

Kieran Klaassen is General Manager of Cora, the email product Every runs, and he wrote *Compound Engineering: The Definitive Guide* in February 2026. He is the recurring figure in a line of source notes that trace one idea from a blog post to a shipped toolchain.

The idea is stated the same way each time: every unit of engineering work should make the next one easier, not harder. Klaassen's November 2025 pieces start from the practical end. "Stop Coding and Start Planning" argues that generative AI made engineers sloppy about planning, and sorts work into three fidelities, with the Fidelity Two sweet spot (multi-file features, clear scope, non-obvious implementation) as where compounding pays. The follow-up turns that philosophy into eight research strategies, each with its own "how to make this compound" clause: reproduce before fixing, read the git history, prototype to clarify, review with style agents that accumulate taste.

The definitive guide scales the claim: Every runs five products (Cora, Spiral, Sparkle, Monologue, Proof) with one-person teams, backed by an open source plugin of 40+ agents and 30+ slash commands installable on «Claude Code». Klaassen's own tally on manual authorship is blunt: first attempts have a 95% garbage rate. He places the entry point for «Compound Engineering» at stage 3 of a five-stage ladder, plan-first with PR-level review.

The July 2026 «Thinkroom» guide moves the problem again. Writing lessons down was never the bottleneck; retrieval was, and postmortems rot in wikis.