”MATS 9 Retrospective & Advice” by beyarkay

I couldn’t find a recent write-up from a MATS alum about what attending MATS was like, so this is the thing that I wish I had. I attended MATS from January to March 2026, on Team Shard with Alex Turner and Alex Cloud. It was a great time! Applications for MATS are basically on a rolling basis nowadays, and I can strongly recommend applying (to multiple streams) even if you think you’re not a great match.

With that being said, there's a lot I wish I knew going into MATS, so here's a brain-dump of thoughts. It's not extremely polished, but I expect it’ll be useful nonetheless (none of this is endorsed by MATS, just my thoughts):

Work ethic

I think most mentees were working 10-12, sometimes 14 hours a day Mon-Fri, and probably 2-8 hours on Saturday and Sunday, often going out on some adventure or party on the weekend. Exactly which hours people worked varied wildly. I usually worked 8:30am/9am to 11pm/midnight, with breaks during the day, others worked from midday into the early hours of the morning. This was surprisingly sustainable (IMO); MATS puts a lot of effort into removing all other blockers that you normally [...]

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Outline:

(00:50) Work ethic

(01:29) Use more compute

(02:20) Research requires a lot of compute

(03:12) Applying for jobs during MATS (dont do it)

(04:55) The serious people are in War Mode

(05:44) Do you feel the AGI?

(06:00) Burn rate, efficiency, and decisions

(07:12) insider information

(08:08) Names & Faces

(08:20) Fellows

(08:50) Useful tools

(11:19) Use more Claudes

(12:06) Build nice helper utilities for yourself

(12:59) MATS-mentee-mentor dynamics

(13:45) Working with your mentors

(14:27) Research managers

(14:48) Ops requests

(15:38) Non-MATS events

(16:17) Team Shard

(17:12) Weekly updates

(18:46) Keep a log of your mistakes

(19:06) My running-experiments setup

(27:51) Lighthaven

(28:12) Getting setup with the Compute team

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First published:
May 15th, 2026

Source:
https://www.lesswrong.com/posts/eFD3rozNCZKMe4rTs/mats-9-retrospective-and-advice

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Narrated by TYPE III AUDIO.