Featured postApril 8, 20265 min read
What Changed After Hitting 1B tokens/month
Doubling my token cost every month at what cost
AI AgentsTooling

Casey Hillers
AI tooling, systems, and practical engineering notes
Engineering notes, experiments, and personal projects.
Why flat-rate AI subscriptions aren't the cash incinerator they look like on paper.
Moving from vibe coding prototypes to production-ready AI engineering workflows.
In an era of yes-men, be different.
Learnings from OpenAI about the state of Codex
Gen Z adventure into dusty tapes
How cool HSMs are and why cloud based cryptographic operations are cheaper
Evolution of Generative AI in 2025
Learning to embrace the mess
Reflections on leading the development of the first Android agent, combining computer use models with virtual displays for background tasks