Pablo Samuel Castro
@pcastr.bsky.social
Señor swesearcher @ Google DeepMind, adjunct prof at Université de Montréal and Mila. Musician. From 🇪🇨 living in 🇨🇦.
https://psc-g.github.io/
https://psc-g.github.io/
Pinned
thrilled to finally put out the second release from my musical project "the 45s" with my buddy JS Diallo!
open.spotify.com/album/0Eb3vq...
open.spotify.com/album/0Eb3vq...
Today's wordle spoke volumes.
Wordle 1,677 2/6
⬛🟩⬛🟩🟩
🟩🟩🟩🟩🟩
P.S. here's a selfie of my x-country ski commute this morning 😃🎿
Wordle 1,677 2/6
⬛🟩⬛🟩🟩
🟩🟩🟩🟩🟩
P.S. here's a selfie of my x-country ski commute this morning 😃🎿
January 21, 2026 at 2:55 PM
Today's wordle spoke volumes.
Wordle 1,677 2/6
⬛🟩⬛🟩🟩
🟩🟩🟩🟩🟩
P.S. here's a selfie of my x-country ski commute this morning 😃🎿
Wordle 1,677 2/6
⬛🟩⬛🟩🟩
🟩🟩🟩🟩🟩
P.S. here's a selfie of my x-country ski commute this morning 😃🎿
Today's wordle energized me
Wordle 1,662 2/6
🟨🟩🟩⬛⬛
🟩🟩🟩🟩🟩
Wordle 1,662 2/6
🟨🟩🟩⬛⬛
🟩🟩🟩🟩🟩
January 7, 2026 at 4:19 AM
Today's wordle energized me
Wordle 1,662 2/6
🟨🟩🟩⬛⬛
🟩🟩🟩🟩🟩
Wordle 1,662 2/6
🟨🟩🟩⬛⬛
🟩🟩🟩🟩🟩
How I started 2026, hoping to keep this spirit up throughout the year!
Happy new year!
Happy new year!
January 2, 2026 at 8:37 PM
How I started 2026, hoping to keep this spirit up throughout the year!
Happy new year!
Happy new year!
Another one of my favorite spots in Ecuador: El Pailón del Diablo 🇪🇨
December 30, 2025 at 11:23 PM
Another one of my favorite spots in Ecuador: El Pailón del Diablo 🇪🇨
Gets better the closer you get 🏔️🇪🇨
December 29, 2025 at 10:24 PM
Gets better the closer you get 🏔️🇪🇨
Will never tire of this view ❤️🇪🇨
December 26, 2025 at 2:26 PM
Will never tire of this view ❤️🇪🇨
Reposted by Pablo Samuel Castro
Hi RL Enthusiasts!
RLC is coming to Montreal, Quebec, in the summer: Aug 16–19, 2026!
Call for Papers is up now:
Abstract: Mar 1 (AOE)
Submission: Mar 5 (AOE)
Excited to see what you’ve been up to - Submit your best work!
rl-conference.cc/callforpaper...
Please share widely!
RLC is coming to Montreal, Quebec, in the summer: Aug 16–19, 2026!
Call for Papers is up now:
Abstract: Mar 1 (AOE)
Submission: Mar 5 (AOE)
Excited to see what you’ve been up to - Submit your best work!
rl-conference.cc/callforpaper...
Please share widely!
RLJ | RLC Call for Papers
rl-conference.cc
December 23, 2025 at 10:16 PM
Hi RL Enthusiasts!
RLC is coming to Montreal, Quebec, in the summer: Aug 16–19, 2026!
Call for Papers is up now:
Abstract: Mar 1 (AOE)
Submission: Mar 5 (AOE)
Excited to see what you’ve been up to - Submit your best work!
rl-conference.cc/callforpaper...
Please share widely!
RLC is coming to Montreal, Quebec, in the summer: Aug 16–19, 2026!
Call for Papers is up now:
Abstract: Mar 1 (AOE)
Submission: Mar 5 (AOE)
Excited to see what you’ve been up to - Submit your best work!
rl-conference.cc/callforpaper...
Please share widely!
Today's wordle made me feel warm.
Wordle 1,646 2/6
⬛🟨🟩⬛⬛
🟩🟩🟩🟩🟩
Wordle 1,646 2/6
⬛🟨🟩⬛⬛
🟩🟩🟩🟩🟩
December 22, 2025 at 4:19 AM
Today's wordle made me feel warm.
Wordle 1,646 2/6
⬛🟨🟩⬛⬛
🟩🟩🟩🟩🟩
Wordle 1,646 2/6
⬛🟨🟩⬛⬛
🟩🟩🟩🟩🟩
Despite some of its flaws, OpenReview has had a tremendously positive impact on our research community.
This is a great initiative! Join me, and many others, in donating to ensure OpenReview not only remains a positive force, but is able to improve.
This is a great initiative! Join me, and many others, in donating to ensure OpenReview not only remains a positive force, but is able to improve.
OpenReview is a pillar of progress in the AI research community. Now it needs our support.
Along with several of my colleagues, I have pledged to help, and I encourage anyone who can to do the same.
openreview.net/donate
Along with several of my colleagues, I have pledged to help, and I encourage anyone who can to do the same.
openreview.net/donate
OpenReview
Promoting openness in scientific communication and the peer-review process
openreview.net
December 20, 2025 at 9:40 PM
Despite some of its flaws, OpenReview has had a tremendously positive impact on our research community.
This is a great initiative! Join me, and many others, in donating to ensure OpenReview not only remains a positive force, but is able to improve.
This is a great initiative! Join me, and many others, in donating to ensure OpenReview not only remains a positive force, but is able to improve.
This #NeurIPS2025 was tiring, but it was fantastic to connect with so many friends and colleagues!
I was so busy I didn't get a chance to tweemote our papers at the conference, so I'll remedy that with this post-hoc thread: 👇🏾
I was so busy I didn't get a chance to tweemote our papers at the conference, so I'll remedy that with this post-hoc thread: 👇🏾
December 10, 2025 at 9:49 PM
This #NeurIPS2025 was tiring, but it was fantastic to connect with so many friends and colleagues!
I was so busy I didn't get a chance to tweemote our papers at the conference, so I'll remedy that with this post-hoc thread: 👇🏾
I was so busy I didn't get a chance to tweemote our papers at the conference, so I'll remedy that with this post-hoc thread: 👇🏾
Sixth, and last, #runconference at #NeurIPS2025 had the best turnout yet!
Thanks to everyone who came out, until the next conference!
The second picture is of those who stayed until the end 😅🏅
🤖🏃🏾👋🏾
Thanks to everyone who came out, until the next conference!
The second picture is of those who stayed until the end 😅🏅
🤖🏃🏾👋🏾
December 7, 2025 at 5:49 PM
Sixth, and last, #runconference at #NeurIPS2025 had the best turnout yet!
Thanks to everyone who came out, until the next conference!
The second picture is of those who stayed until the end 😅🏅
🤖🏃🏾👋🏾
Thanks to everyone who came out, until the next conference!
The second picture is of those who stayed until the end 😅🏅
🤖🏃🏾👋🏾
Fifth #runconference at #NeurIPS2025 , good turnout again!
Tomorrow is the last run (at least with me), so if you've had FOMO this week, you have one more chance!
🤖🏃🏾
Tomorrow is the last run (at least with me), so if you've had FOMO this week, you have one more chance!
🤖🏃🏾
December 7, 2025 at 12:11 AM
Fifth #runconference at #NeurIPS2025 , good turnout again!
Tomorrow is the last run (at least with me), so if you've had FOMO this week, you have one more chance!
🤖🏃🏾
Tomorrow is the last run (at least with me), so if you've had FOMO this week, you have one more chance!
🤖🏃🏾
Fourth #runconference at #NeurIPS2025 had the best turnout yet!
Help us beat it tomorrow, same place, same time (follow tweet thread for details)!
🤖🏃🏾
Help us beat it tomorrow, same place, same time (follow tweet thread for details)!
🤖🏃🏾
December 6, 2025 at 1:22 AM
Fourth #runconference at #NeurIPS2025 had the best turnout yet!
Help us beat it tomorrow, same place, same time (follow tweet thread for details)!
🤖🏃🏾
Help us beat it tomorrow, same place, same time (follow tweet thread for details)!
🤖🏃🏾
Third #runconference at #NeurIPS2025 was great, including special guest @JeffDean !
Same place, same time, tomorrow morning if you want to join!
🤖🏃🏾
(I forgot to post yesterday's pic, so including it here)
Same place, same time, tomorrow morning if you want to join!
🤖🏃🏾
(I forgot to post yesterday's pic, so including it here)
December 4, 2025 at 7:15 PM
Third #runconference at #NeurIPS2025 was great, including special guest @JeffDean !
Same place, same time, tomorrow morning if you want to join!
🤖🏃🏾
(I forgot to post yesterday's pic, so including it here)
Same place, same time, tomorrow morning if you want to join!
🤖🏃🏾
(I forgot to post yesterday's pic, so including it here)
. @roger-creus.bsky.social and @johanobandoc.bsky.social did an awesome job presenting our paper at the LatinX in AI workshop at #NeurIPS .
If you missed it, come to our poster #310 on Friday 11am, exhibit hall C,D,E.
If you missed it, come to our poster #310 on Friday 11am, exhibit hall C,D,E.
December 3, 2025 at 12:53 AM
. @roger-creus.bsky.social and @johanobandoc.bsky.social did an awesome job presenting our paper at the LatinX in AI workshop at #NeurIPS .
If you missed it, come to our poster #310 on Friday 11am, exhibit hall C,D,E.
If you missed it, come to our poster #310 on Friday 11am, exhibit hall C,D,E.
Join us tomorrow at #runconference for #NeurIPS2015, same time, same place (see quoted thread for details)!
It was three of us this morning but I forgot to take a picture before we separated, so here's a selfie to prove we actually went out 🤭
Hope to see more of you tomorrow!
It was three of us this morning but I forgot to take a picture before we separated, so here's a selfie to prove we actually went out 🤭
Hope to see more of you tomorrow!
December 2, 2025 at 9:38 PM
Join us tomorrow at #runconference for #NeurIPS2015, same time, same place (see quoted thread for details)!
It was three of us this morning but I forgot to take a picture before we separated, so here's a selfie to prove we actually went out 🤭
Hope to see more of you tomorrow!
It was three of us this morning but I forgot to take a picture before we separated, so here's a selfie to prove we actually went out 🤭
Hope to see more of you tomorrow!
Just landed in San Diego for #NeurIPS2025 !
If anyone wants to join me for #runconference tomorrow, meet me at the pin at 7:00am. We'll play distance and pace by ear, based on who shows up
See you then!
🤖🏃🏾
maps.app.goo.gl/W7fedHdpsrFn...
If anyone wants to join me for #runconference tomorrow, meet me at the pin at 7:00am. We'll play distance and pace by ear, based on who shows up
See you then!
🤖🏃🏾
maps.app.goo.gl/W7fedHdpsrFn...
December 1, 2025 at 10:17 PM
Just landed in San Diego for #NeurIPS2025 !
If anyone wants to join me for #runconference tomorrow, meet me at the pin at 7:00am. We'll play distance and pace by ear, based on who shows up
See you then!
🤖🏃🏾
maps.app.goo.gl/W7fedHdpsrFn...
If anyone wants to join me for #runconference tomorrow, meet me at the pin at 7:00am. We'll play distance and pace by ear, based on who shows up
See you then!
🤖🏃🏾
maps.app.goo.gl/W7fedHdpsrFn...
Today's wordle was received as a gift.
Wordle 1,622 2/6
⬛🟩🟩⬛⬛
🟩🟩🟩🟩🟩
Wordle 1,622 2/6
⬛🟩🟩⬛⬛
🟩🟩🟩🟩🟩
November 28, 2025 at 4:15 AM
Today's wordle was received as a gift.
Wordle 1,622 2/6
⬛🟩🟩⬛⬛
🟩🟩🟩🟩🟩
Wordle 1,622 2/6
⬛🟩🟩⬛⬛
🟩🟩🟩🟩🟩
Reposted by Pablo Samuel Castro
My lab is looking for new students who are very passionate about foundational models and planning/RL/robotics. Apply via Mila. I will also be at #NeurIPS to discuss research ideas and opportunities. See notes below for application advice.
November 19, 2025 at 3:10 PM
My lab is looking for new students who are very passionate about foundational models and planning/RL/robotics. Apply via Mila. I will also be at #NeurIPS to discuss research ideas and opportunities. See notes below for application advice.
🚨The Formalism-Implementation Gap in RL research🚨
Lots of progress in RL research over last 10 years, but too much performance-driven => overfitting to benchmarks (like the ALE).
1⃣ Let's advance science of RL
2⃣ Let's be explicit about how benchmarks map to formalism
1/X
Lots of progress in RL research over last 10 years, but too much performance-driven => overfitting to benchmarks (like the ALE).
1⃣ Let's advance science of RL
2⃣ Let's be explicit about how benchmarks map to formalism
1/X
October 28, 2025 at 1:56 PM
🚨The Formalism-Implementation Gap in RL research🚨
Lots of progress in RL research over last 10 years, but too much performance-driven => overfitting to benchmarks (like the ALE).
1⃣ Let's advance science of RL
2⃣ Let's be explicit about how benchmarks map to formalism
1/X
Lots of progress in RL research over last 10 years, but too much performance-driven => overfitting to benchmarks (like the ALE).
1⃣ Let's advance science of RL
2⃣ Let's be explicit about how benchmarks map to formalism
1/X
Reposted by Pablo Samuel Castro
Proud to announce that Meta-World+ was accepted to NeurIPs, Datasets and Benchmarks! Meta-World is a common benchmark for multi-task and meta-RL research! However, it was very difficult to do effective science with Meta-World as different versions produce different results.
September 19, 2025 at 11:21 PM
Proud to announce that Meta-World+ was accepted to NeurIPs, Datasets and Benchmarks! Meta-World is a common benchmark for multi-task and meta-RL research! However, it was very difficult to do effective science with Meta-World as different versions produce different results.
🔊Simplicial Embeddings (SEMs) Improve Sample Efficiency in Actor-Critic Agents🔊
In our recent preprint we demonstrate that the use of well-structured representations (SEMs) can dramatically improve sample efficiency in RL agents.
1/X
In our recent preprint we demonstrate that the use of well-structured representations (SEMs) can dramatically improve sample efficiency in RL agents.
1/X
October 20, 2025 at 2:07 PM
🔊Simplicial Embeddings (SEMs) Improve Sample Efficiency in Actor-Critic Agents🔊
In our recent preprint we demonstrate that the use of well-structured representations (SEMs) can dramatically improve sample efficiency in RL agents.
1/X
In our recent preprint we demonstrate that the use of well-structured representations (SEMs) can dramatically improve sample efficiency in RL agents.
1/X
Reposted by Pablo Samuel Castro
Very excited to be able to talk about something I've been working on for a while now - we're working with Commonwealth Fusion Systems, IMO the leading fusion startup in the world, to take our work on AI and tokamaks and make it work at the frontier of fusion energy. deepmind.google/discover/blo...
Google DeepMind is bringing AI to the next generation of fusion energy
We’re announcing our research partnership with Commonwealth Fusion Systems (CFS) to bring clean, safe, limitless fusion energy closer to reality with our advanced AI systems. This partnership...
deepmind.google
October 16, 2025 at 1:55 PM
Very excited to be able to talk about something I've been working on for a while now - we're working with Commonwealth Fusion Systems, IMO the leading fusion startup in the world, to take our work on AI and tokamaks and make it work at the frontier of fusion energy. deepmind.google/discover/blo...
Reposted by Pablo Samuel Castro
Hello everyone 👋 Good news!
🚨 Our Game Theory & Multiagent Systems team at Google DeepMind is hiring! 🚨
.. and we have not one, but two open positions! One Research Scientist role and one Research Engineer role. 😁
Please repost and tell anyone who might be interested!
Details in thread below 👇
🚨 Our Game Theory & Multiagent Systems team at Google DeepMind is hiring! 🚨
.. and we have not one, but two open positions! One Research Scientist role and one Research Engineer role. 😁
Please repost and tell anyone who might be interested!
Details in thread below 👇
September 29, 2025 at 12:36 PM
Hello everyone 👋 Good news!
🚨 Our Game Theory & Multiagent Systems team at Google DeepMind is hiring! 🚨
.. and we have not one, but two open positions! One Research Scientist role and one Research Engineer role. 😁
Please repost and tell anyone who might be interested!
Details in thread below 👇
🚨 Our Game Theory & Multiagent Systems team at Google DeepMind is hiring! 🚨
.. and we have not one, but two open positions! One Research Scientist role and one Research Engineer role. 😁
Please repost and tell anyone who might be interested!
Details in thread below 👇
this was a really great workshop at @rl-conference.bsky.social , and i enjoyed giving a talk and moderating a panel there.
everything was recorded, so if you weren't able to join, you can watch it now, link below.
everything was recorded, so if you weren't able to join, you can watch it now, link below.
Missed our workshop at @rl-conference.bsky.social?
Watch all keynote presentations and the panel discussion on YouTube:
youtube.com/playlist?lis...
Big thanks to our awesome speakers: @togelius.bsky.social, @jmac-ai.bsky.social, Roberta Raileanu, Michael Bowling and @pcastr.bsky.social!
Watch all keynote presentations and the panel discussion on YouTube:
youtube.com/playlist?lis...
Big thanks to our awesome speakers: @togelius.bsky.social, @jmac-ai.bsky.social, Roberta Raileanu, Michael Bowling and @pcastr.bsky.social!
RLVG Sessions @ RLC 2025 - YouTube
Recorded sessions of the Reinforcement Learning and Video Games (RLVG) workshop at the Reinforcement Learning Conference (RLC), 2025. Recorded on August 5, 2025
youtube.com
September 29, 2025 at 10:25 AM
this was a really great workshop at @rl-conference.bsky.social , and i enjoyed giving a talk and moderating a panel there.
everything was recorded, so if you weren't able to join, you can watch it now, link below.
everything was recorded, so if you weren't able to join, you can watch it now, link below.