Essays5 selectedcaskeycoding.comupdated
Selected writing
Eric Caskey writes long-form engineering essays at Caskey Engineering on spec-driven development, safety guardrails for distributed systems, and AI reliability. The five selected here best show the method rather than the result: a C++ options pricer tuned from 15 to 215 million prices a second, where most of the speedup assumptions died one measurement at a time; Ballast, a RAG system whose most important feature is refusing to answer; an honest account of building a personal finance reviewer, where the hard part was rarely the AI; the validation engines behind workflow orchestration, where an incorrect "yes" is a production incident; and the folder architecture that lets AI agents and humans both find their way around a codebase. The full archive lives at Caskey Engineering.
July 9, 2026
Pricing 215 million options a second with SIMD C++
A clean C++ options pricer, tuned from 15 to 215 million prices a second. Most of my speedup assumptions died one measurement at a time.
Caskey Engineering
June 27, 2026
Ballast: An LLM App Whose Best Feature Is Saying 'I Don't Know'
A RAG system whose most important feature is refusing to answer. How trust got built into the architecture instead of the prompt.
Caskey Engineering
May 19, 2026
Building a Personal Finance Reviewer: What Survived the Rewrite
An honest account of what worked, what did not, and why the hard part is rarely the AI.
Caskey Engineering
April 10, 2026
Designing Safety Guardrails for Distributed Workflow Orchestration
What I've learned building validation engines for infrastructure where an incorrect “yes” is a production incident.
Caskey Engineering
April 9, 2026
Spec-Driven Development and the Folder Architecture That Makes It Work
How I structure projects so AI agents and humans can both find their way around. This is the methodology behind everything else.
Caskey Engineering