LessWrong (30+ Karma) “How To Become A Mechanistic Interpretability Researcher” by Neel Nanda
Note: If you’ll forgive the shameless self-promotion, applications for my MATS stream are open until Sept 12. I help people write a mech interp paper, often accept promising people new to mech interp, and alumni often have careers as mech interp researchers. If you’re interested in this post I recommend applying! The application should be educational whatever happens: you spend a weekend doing a small mech interp research project, and show me what you learned.
Last updated Sept 2 2025
TL;DR
- This post is about the mindset and process I recommend if you want to do mechanistic interpretability research. I aim to give a clear sense of direction, so give opinionated advice and concrete recommendations.
- Mech interp is high-leverage, impactful, and learnable on your own with short feedback loops and modest compute.
- Learn the minimum viable basics, then do research. Mech interp is an empirical science
- Three stages:
- [...]
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Outline:
(00:45) TL;DR
(06:26) Introduction
(07:42) High-Level Framing
(09:36) Stage 1: Learning the Ropes
(10:41) Machine Learning & Transformer Basics
(13:22) Mechanistic Interpretability Techniques
(15:57) Mechanistic Interpretability Coding & Tooling
(19:40) Understanding the literature
(22:45) Using LLMs for Learning
(27:38) Interlude: What is mech interp?
(31:27) The Big Picture: Learning the Craft of Research
(33:24) Unpacking the Research Process
(37:04) What is research taste?
(38:28) Stage 2: Practicing Research with Mini-Projects
(39:28) Choose A Project
(43:04) Practicing Exploration
(45:51) Practicing Understanding
(48:09) Using LLMs for Research Code
(49:33) Interlude: What's New In Mechanistic Interpretability?
(49:56) Avoiding Fads
(53:58) What's New In Mech Interp?
(01:00:10) A Pragmatic Vision for Mech Interp
(01:01:42) Stage 3: Working Up To Full Research Projects
(01:03:12) Key Research Mindsets
(01:09:22) Deepening Your Skills
(01:16:59) Practicing Ideation
(01:21:19) Write up your work!
(01:27:33) Mentorship, Collaboration and Sharing Your Work
(01:28:02) So what does a research mentor actually do?
(01:30:23) Advice on finding a mentor
(01:35:53) Community & collaborators
(01:37:54) Careers
(01:37:57) Where to apply
(01:39:30) What do hiring managers look for
(01:42:44) Should you do a PhD?
The original text contained 36 footnotes which were omitted from this narration.
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First published:
September 2nd, 2025
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Narrated by TYPE III AUDIO.