November 2, 2026 · AI 101
AI 101: What Is a Context Window?
The context window is the AI's working memory: everything it can hold in mind at once. Like ours, it can get overloaded. How I check, and when I start a fresh session.
NameLin, Michelle, MD
ServiceEmergency Medicine
FacilityUCSF · San Francisco General
AllergiesBureaucracy
Michelle Lin, MD
Professor of Emergency Medicine at UCSF · founder of ALiEM · AI tinkererdirects AI systems(the words "AI tinkerer" are crossed out in red pen and corrected to "directs AI systems")
the old site really did call me a "tinkerer." corrected, June 2026.
I spent 25 years becoming a professor of emergency medicine. Then I learned to build. I don't write code. I direct it, the way an attending directs a resuscitation: clear intent, constant verification, no pretending to know things I don't. These days I'm building AI systems for academic clinicians and writing down what I learn, mistakes included.
Get in touchMessages come straight to my inbox, not an intake form.
Flowsheet· career vitals · checked October 2026
25 yrs
UCSF faculty · Professor since 2015
2M
readers a year at ALiEM
67
peer-reviewed papers
0
lines of code written
still true. I checked.Now
Interval note · October 2026Active problems
- Writing the AI Learning Journal. Latest entry: AI 101: What Is a Context Window?.
- Running two systems in daily use: PAIA, my AI chief of staff, and a promotion-letter drafting workflow the UCSF EM promotion committee uses.
- Studying paramedic radio calls, poison center calls, and SF EMS records with AI, in three IRB-approved QI studies.
The AI Learning Journal
Progress notes- November 1, 2026AI 101
AI 101: What Is Markdown?
Markdown is plain text with a few symbols for structure: # for a heading, ** for bold. AI chats format their replies in it, and it's an easy way to hand notes to an AI.
- October 31, 2026AI 101
AI 101: What Is a Token?
AI doesn't read words. It reads tokens, small chunks of text. Two reasons a beginner should care: how much the AI can hold at once, and what API use costs.
- October 30, 2026AI 201
AI 201: Why I Have a Second AI Check the First
I have Codex, OpenAI's version of Claude Code, review what Claude Code builds and writes: as an editor, an adversarial reviewer, and a skeptic. How to set it up, why a role beats "are you sure?", and why a person still makes the final call.
- October 25, 2026AI 101
AI 101: What Is an API?
An API lets a program use an online tool like PubMed, Kit, or Tally without opening its website. Here are three I use, what they cost, and the downsides.
- October 24, 2026AI 101
AI 101: 3 Mac Skills I Wish I'd Known Before Using Claude Code
Three Mac shortcuts I use every day with Claude Code: a screenshot straight to your clipboard, a hotkey for dictation, and copying a file's path.
The Builds
Medication list · reconciled October 2026Two systems in daily use, three IRB-approved studies in progress.
| System | Status | What it is |
|---|---|---|
| Faculty Promotion Letter Automation | In daily use | n8n workflow that curates faculty documents and generates first-draft promotion letters with transparent audit trails and flags for human review. Currently in use by UCSF EM promotion committee. |
| PAIA: Executive AI Assistant | In daily use | Personal AI assistant built with Claude's Agent SDK featuring memory, journaling, board of directors advisory sessions, CRM, YouTube video analyzer, and growing skill library. |
| Base Hospital Radio Call Analysis | IRB-approved QI · in progress | AI-powered transcription and QI analysis of base hospital radio calls between paramedics and physicians. |
| California Poison Center Call Analysis | IRB-approved QI · in progress | Using AI to transcribe and analyze poison center calls for quality improvement insights. |
| SF EMS Medical Record QI Analysis | IRB-approved QI · in progress | AI-driven quality improvement analysis of San Francisco EMS Agency patient care records. |
The Record
Past history · 1993 → present- UCSF / Zuckerberg San Francisco General
- Professor of Emergency Medicine (faculty 2001–, Professor 2015–). Practicing at ZSFG; Director of the Digital Innovation Lab.
- ALiEM — Academic Life in Emergency Medicine
- Founder & Editor-in-Chief, 2008–. Grew a solo blog into one of the world's most-visited med-ed sites, 2M+ annual views.
- ALiEMU
- Co-created free learning management system, 2014–. 75,000+ course completions.
- #PostitPearls
- Hand-drawn post-it teaching doodles from the ED, 2017–.
- Publications
- 67 peer-reviewed papers across Digital Scholarship & Social Media (28), Medical Education Scholarship (15), ALiEM AIR Series (9), Wellness & Burnout (6), Virtual Communities & Mentorship (5), COVID-19 & Virtual Education (4).
- Education & training
- Stanford BS (Biology) and Stanford MD; emergency medicine residency at Harbor-UCLA.
- Elsewhere
- EM editor at DynaMed. Dissemination lead, PECARN SPARC node. "The Lin Sessions" on EM:RAP.
Tricks of
the Trade
the Trade
Tricks of the Trade in Emergency Medicine - 50 clinical tricks from 38 experts, 100+ photos, expert authors, real-world tips. Buy a copy or read about it.
Signed and dated · October 2026