Field notes · 8 and counting · the front door

Real incidents, mapped in public — free.

Every note teaches one decision the way the academy does — stake, map, verdict. When a note hooks you, it routes you into the exact course sprint that trains the skill.

Repair logLATEST · THE MONDAY NOTEThe invoice that emailed itself twiceFour customers got billed twice, eleven minutes apart, from a job that logs say ran once. The retry wrapper we added to fix reliability couldn't tell a slow success from a failure.Jun 2026 · 3 min · routes → Backend EngineeringRead the note →

8 notes · showing all 8

Repair logThe invoice that emailed itself twiceJun 20263 minroutes → Backend Engineering→SystemsBlast radius: the map nobody draws before Friday deploysJun 20262 minroutes → Engineering Judgment→AIYour RAG eval is lying to you (and how to catch it)Jun 20263 minroutes → AI Engineering & RAG→AuditThe AI implementation audit: 11 questions before you shipMay 20263 minroutes → AI Engineering & RAG→SystemsThe cron that ran on two clocksMay 20262 minroutes → Engineering Judgment→Repair logPostmortem: the retry storm that took the pool downMay 20262 minroutes → Backend Engineering→CareerInterviews as proof presentations: pick any claimApr 20262 minroutes → Interview & Portfolio→GrowthSEO as an engineering system, not a checklistApr 20263 minroutes → Product Execution→

The Monday noteA new incident, mapped in public, every Monday — the same one the weekly challenge runs.