Robert Weber

Talent + Compute @amppublic | prev. Partner @a16z

[Robert Weber @RobertNWeber]

@AnjneyMidha @vivianmshen Congratulations! Here’s to many more happy and healthy years!

[Anastasios Nikolas Angelopoulos @ml_angelopoulos]

I come from a family of Greek immigrants that came to this country for a better life.

@america has given us extraordinary opportunity to improve our situation. My grandfather was a waiter. He raised a doctor, an executive, and a professor. My father came as a graduate student to contribute to space science and technology. My wife is an amazing scientist and professor at Stanford, another immigrant from Serbia. I’d never have met her without the opportunities this country gave us.

Great people from all over come to America to enjoy the freedom and meritocracy that you can’t get anywhere else. We celebrate our diverse cultures while achieving in our careers at the highest level, and ultimately doing something meaningful with our lives. Today is a great reminder to protect the values that make our country special.

I am so proud to be a Greek-American. Happy 250, @america!

[Vivian Midha Shen @vivianmshen]

happy 250th birthday to the greatest place on earth 🇺🇸🇺🇸

[Anthony Mensah @mranthonymensah]

A paper I co-authored called "Building an LLM-Powered Content Moderation Bot in the Classroom" just got published in Cambridge Press. Like + sub!

https://t.co/RV4Ga916Rd

[Robert Weber @RobertNWeber]

@mranthonymensah Congratulations @mranthonymensah !!

[Anastasios Nikolas Angelopoulos @ml_angelopoulos]

Arena has crossed $100M in annualized revenue run rate, eight months after launching our evaluation product.

With our recent release of Agent Mode, millions of users on Arena are doing real work with agents, from coding to document analysis, in long-running, multi-turn sessions with hundreds of tool calls. Arena now evaluates objective criteria like task completion rates, hallucination rates, and more, far beyond our original human preference voting model. This expansion has taken us from a student project at Berkeley to one of the fastest growing companies in history. Go Bears! 🐻

Our core thesis is simple: to align AI with human values, we must directly measure its impact on people in the real world. Today's milestone is proof that Arena’s platform is the de-facto standard for post-deployment evaluation of AI.

[Robert Weber @RobertNWeber]

@ml_angelopoulos Woohoo! Congratulations!!

[Erin Price-Wright @espricewright]

If you're a naturally anxious person, I recommend pursuing a high stress career path where at least you'll be compensated for anxiety you're going to have anyways.

[Rishabh Agarwal @agarwl_]

I gave a talk at ICLR 2026 about how we are scaling RL on frontier LLMs with 1T+ parameters, on experimental data from our physical lab at Periodic!

Here's a rough recording of the talk:

[Robert Weber @RobertNWeber]

@drfeifei @cs231n @Stanford Packed house! What a special class to be able to attend. Needs a bleachers section!

[Robert Weber @RobertNWeber]

@AnjneyMidha @CS153Systems Amazing class, and this upcoming lineup is ridiculous. When is the world tour? Sphere residency feels like the only logical next step.

[atlas @creatine_cycle]

the legends at @soontechnology and I have been on a mission to find the most jacked AI researcher and we think that @LiamFedus, co-creator of ChatGPT and co-founder of @periodiclabs might be it.

check out the latest episode of Swole as a Service where he totally framemogs me while discussing whether or not AI will replace scientists

00:21 Who is Liam Fedus?
01:21 Lying skull crushers & will AI replace scientists?
03:05 Barbell curls, Jayden’s fitness tips, & why build an AI scientist now?
05:17 Hammer curls & is the singularity imminent?
07:43 Sleds & is the permanent underclass meme real?
08:37 Chestmaxxer Challenge & why hasn’t AI cured all diseases?

[Robert Weber @RobertNWeber]

@xanderai @periodiclabs beast > cracked

[Xander Dunn @xanderai]

I am so incredibly grateful to be a part of @periodiclabs. Seriously, beast company, beast opportunity, beast colleagues.

[Robert Weber @RobertNWeber]

@simon_mo_ @vllm_project @nvidia @inferact Congrats @simon_mo_ and @inferact. It’s been a blast working with you!

[Robert Weber @RobertNWeber]

@DanielChao4 @theworldlabs Congrats Daniel!!

[Robert Weber @RobertNWeber]

Back in the day I used to ask this question to junior recruiter candidates:

A natural disaster is about to hit LA. What's your plan to save as many people as possible?

It was interesting to gauge someone's critical thinking, thought process, logic, etc. A lot didn't think to ask what the natural disaster was.

[Robert Weber @RobertNWeber]

@weberwongwong From one Weber to another. Congratulations!

[Robert Weber @RobertNWeber]

@bridgitmendler @WashingHarbour Amazing. Congrats team!!

[Matt Bornstein @BornsteinMatt]

[New deal] We're leading the $150m seed round for @inferact to support the @vllm_project

Inference will soon be the bottleneck in the AI industry, if its not already. And vLLM is one of the critical pieces of the stack.

Congratulations @woosuk_k @simon_mo_ @KaichaoYou @rogerw0108!