N Newsletters to 1 Digest, Built for AI Engineers

Writeup of a multi-stage LLM pipeline I've been running unattended for a while: fetch the article behind each newsletter link, summarize, de-dupe across sources, score on importance and urgency, publish. A few things that made it survivable — every model response is schema-validated and a non-conforming response is rejected rather than quietly reshaped, ambiguous de-dupe pairs escalate to a second model instead of trusting a threshold, and the pipeline grades its own output so the site holds publication when the health block isn't green. The input is adversarial by construction since an attacker controls the entire body of any email it ingests, so there are five layers of prompt-injection defense in front of the model. Happy to go deeper on any of those.