Engineering manager @meta MSL. After work - @BattleCastGG and e4developer.com

Joined January 2011
264 Photos and videos
I think we did a pretty good job at MSL 😎
Apr 27
GPT-5.5 by @OpenAI is now live in the Arena, landing across multiple leaderboards. Here’s how it ranks by modality: - Code Arena (agentic web dev): #9, a strong 50pt jump over GPT-5.4 - Document Arena (analysis & long-content reasoning): #6, on par with Sonnet 4.6 - Text Arena: #7, Math #3, Instruction Following: #8 - Expert Arena: #5 - Search Arena: #2 - Vision Arena: #5 Strong, well-rounded performance, especially in Code ( 50 pts vs GPT-5.4). Congrats to @OpenAI on the release. Full category breakdowns by modality in the thread.
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I’ve never had as much fun being software engineer as I’m having now. The speed of turning ideas into concrete work is something else!
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Bartosz Jedrzejewski retweeted
I have simulated 6.8 million battles to find the strongest CR1 monster... I have been in a crazy rabbit hole over the past month trying to build as complete as possible D&D simulator. I think I am in a good place where most basic things and tactics work pretty well... So i have decided to do the think I always wanted - run crazy scale D&D simulations! Hope you enjoy - battlecast.gg/blog/strongest… Let me know if you have other "D&D science experiments" ideas!
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Replying to @Pack_Tacticss
@Pack_Tacticss hey! I see you post really cool tactical content on youtube! Was wondering if you would be intereted in checking out battlecast.gg (100% free project I created) and if there are any features that would make it more interesting for you!
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Also - Kobolds are just the best!
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I kept asking ChatGPT and Claude who would win D&D battles. Different models gave different answers. The same model changed its mind if I asked again. So I built the thing myself - a grid-based combat simulator with 317 monsters, real 5e rules, and 10,000-trial Monte Carlo analysis. Three weeks of evenings and weekends. It hit #1 on r/dndnext. A year ago this would have taken months. I wrote about how AI coding tools changed the equation - and where they didn't help at all (Reddit to the rescue!). Try it: battlecast.gg Read the full story: e4developer.com/posts/how-i-…
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Bartosz Jedrzejewski retweeted
10 Cats vs 1 lvl 1 Wizard is a pretty balanced fight in D&D! You can try other matchups on battlecast.gg #DnD #DnD5e #DMTools
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Bartosz Jedrzejewski retweeted
After amazing feedback from the Reddit post - reddit.com/r/dndnext/comment… I have been crazy busy implementing dozens of fixes. The simulation is getting quite stable and reliable now!
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Bartosz Jedrzejewski retweeted
It takes about 8 Hobgoblins to make a fair fight against a Level 6 Barbarian. 10,000 simulations. 54/46 win rate. What matchups do you want to see? battlecast.gg
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I've been building BattleCast (battlecast.gg) - a D&D 5e combat simulator where you watch the battles play out on a grid. 82 SRD monsters, different tactics, Monte Carlo win probability analysis, animated replays. All in the browser. Very early stage - feedback welcome!
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Bartosz Jedrzejewski retweeted
okay this is too exciting :) meta AI is now #2 in the app store, top AI app! we are so back!
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Bartosz Jedrzejewski retweeted
Replying to @alexandr_wang
It’s #1 in the productivity category now
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Bartosz Jedrzejewski retweeted
Go open Meta AI app -> Do something fun -> Create an arcade game -> reply here with the result!
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Proud to have been a part of this journey! This is just the beginning 😎⚡️
1/ today we're releasing muse spark, the first model from MSL. nine months ago we rebuilt our ai stack from scratch. new infrastructure, new architecture, new data pipelines. muse spark is the result of that work, and now it powers meta ai. 🧵
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Bartosz Jedrzejewski retweeted
If you care about campaign and legacy games, this one came out properly sharp. The short version: Pandemic Legacy: Season 1 is still the benchmark, but the field is much deeper in 2026 than people give it credit for. New on The Dice Drop: thedicedrop.com/posts/the-be…
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Bartosz Jedrzejewski retweeted
Every nature & wildlife board game worth owning, from gateway to epic. The definitive guide to nature & wildlife on your table. thedicedrop.com/posts/theme-…
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Bartosz Jedrzejewski retweeted
We're tracking 4,366 indie games on Steam right now. The most-reviewed indie game? Terraria — 1.5 million reviews at 97.4% positive. But here's the real find: The Artisan of Glimmith has 333 reviews at 99.4% positive. Almost perfect. That's why we built the Hidden Gems tracker: indiegamedrop.gg/browse/?sor… #indiegames #steam
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I have re-launched my board game focused twitter account- @TheDiceDrop. It now comes with a website thedicedrop.com and is heavily relying on automation. It has been a fantastic project to work on, and I enjoy both the content it produces, as well as improving it!
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