Writing & field notes

Writing

Long-form engineering essays, production retrospectives, and field notes from shipping AI agents to production. Updated when there's something worth saying.

2026-05-13

FastAPI + LangChain template for AI agent SaaS - full walkthrough

A production-tested template that wires FastAPI, LangChain, multi-tenant billing, RAG, and an admin dashboard so you can ship AI agent products in hours instead of weeks. Here's what it includes and how to deploy it.

2026-05-12

FastAPI vs Next.js for AI agents in 2026

Should the AI agent live in your Next.js API routes or in a separate FastAPI backend? Here's the decision matrix from 30+ production AI agent deployments - when Next.js is enough, when FastAPI is mandatory.

2026-05-11

Multi-tenant credits system for AI SaaS - full implementation

How to wire a usage-tracked credits system across Stripe subscriptions, per-organization quotas, and anomaly detection - without hand-rolling 4 weeks of billing infrastructure.