Engineering notes
Notes
Write-ups from systems I've actually built. The decisions, the budgets, and the parts that only look obvious afterwards. Framed as patterns, not incident reports on any one product.
July 2026 · 12 min
Wiring agent observability
Observability used to be logs, then metrics, then distributed traces. Agents added a fourth axis: cost. The Customer Support Crew, wired three ways. Flue's global event bus, Think's per class lifecycle hooks, AgentCore's auto instrumented microVM. Same headline outcome, three completely different wiring philosophies.
July 2026 · 14 min
Three harnesses, one crew: Flue, Think, and Bedrock AgentCore
Two Cloudflare products and one AWS platform, building the same customer support crew. The runtime you pick decides almost everything else: how you declare agents, where subagents run, how memory works, how you trace what happened.
July 2026 · 7 min
Metering streaming AI inference without slowing it down
Every token is money and every request is a transaction, and the ledger can't be on the hot path. A two-phase billing engine for an AI model gateway.
July 2026 · 6 min
Per-PR cloud environments for a CDK-managed AWS platform
Cloudflare and Vercel make preview URLs feel automatic. A Lambda, API, and RDS platform needs the same workflow without duplicating state. Ephemeral CDK stacks fix that, at close to zero idle cost.
July 2026 · 5 min
Deleting every long-lived AWS key from CI
A static access key in CI is a breach waiting for a leak. GitHub OIDC federation with per-repo, per-environment roles, and prod trust policies that grant nothing but change-sets.
January 2026 · 10 min
Durable workflows · Cloudflare Workflows and AWS Durable Functions
Same problem, two products, one naming trap. A ticket reservation with a fifteen minute hold, built on both platforms, and the limits and gotchas that decide which one you pick.
July 2026 · 5 min
Micro-credits: integer money across four data stores
Floats drift, database drivers return strings, and four stores each want money in a different shape. A layered integer model that keeps every layer honest.