Simile

Simulating human behavior 🔮

[Simile @simile_ai]

Today we’re announcing our Series B.

We’ve raised $200M at a $2B valuation from Greenoaks with participation from Index Ventures, Hanabi, A*, Bain Capital Ventures, CVS Health Ventures, and Definition.

Our mission is to simulate all eight billion people on earth, accurately.

[Harry Stebbings @HarryStebbings]

Three weeks ago, I was sitting in the drawing room of the holiday rental my family always gets in July in Frinton-on-Sea (St Tropez of the UK).

It was midnight and as my grandparents were snoring loudly next to me; my phone suddenly buzzed. It was legendary investor, @shardul_shah @IndexVentures.

As much as I love Shardul, it is rare for him to send me a deal and so when he does, I pay attention.

Shardul was sharing @simile_ai with me, suggesting I meet @joon_s_pk. He spoke of all the companies he has backed, their growth being unparalleled. Given the man did Wiz, that really excited me!

I asked for the intro, and 60 mins later, at 1 AM UK time, I was on a call with Joon. Straight away, it was clear he was one of the most unique talents I had met; an ability to be world-class in two seemingly opposing skills: creativity and scientific rigour. The man was a painter before becoming world class AI mind! Wow.

I committed to invest on the call. Why? Joon is obviously insanely special. Second, I care deeply about upside. If this works, what could this be? If this works, it will change marketing forever. It will change stock markets forever. It will change human decision-making in general. Insane.

I had to be a part of it and so I gave Joon a boatload of cash and asked if I could summarise the notes from our conversation below. (Links in comments)

Huge thanks to @BennettSiegel @ninaachadjian @kevinhartz @BryanOffutt @karpathy for amazing thoughts, questions and feedback here.

1. The Question to Ask When Assessing Talent

The best way to evaluate talent is to look for consistent performance across multiple stages of a career, not impressive titles. Ask one question: Were they the common denominator behind every success? Exceptional operators repeatedly create great outcomes across different roles, demonstrating rare ownership and adaptability.

-- @kevinhartz you are one of the single best talent spotters in tech. What is the single biggest commonality in the best founders you have worked with?

2. The Sign of Truly Great Talent

Exceptional talent combines traits that rarely coexist. While most people have correlated strengths, world-class builders embrace cognitive tension. They are short-term paranoid but long-term optimistic—obsessing over daily execution while maintaining unwavering conviction in the bigger picture.

-- @dannyrimer you also have an immense love of art. How has art impacted your view on company building and entrepreneurship?

3. People Will Pay $100 Million for a Single Simulation

AI will enable simulations so valuable that companies will spend tens of millions on a single run. A simulation may cost $20 million in compute, but if it prevents a $500 million product failure, paying $100 million becomes an extraordinary bargain.

-- @GavinSBaker does this align to your views on specialised intelligence?

4. Why Simulation Requires Modeling Human Bias, Not Perfect Logic

Frontier labs are racing to build the “CPU of intelligence” optimized for perfect reasoning. The bigger commercial opportunity may be the “GPU of intelligence”: models that replicate human judgment, bias, and imperfect decision-making to simulate complex real-world markets at scale.

-- @ml_angelopoulos how does the role of evaluations change in this world?

[keeyen @keeyeny]

Series B @simile_ai

[Simile @simile_ai]

We’re building a future where people make better decisions today, by simulating how people will think, decide, and behave before ideas meet the real world.

Read more about what we're building in today's @nytimes. Thank you, @srimuppidi.

https://t.co/kiIfpDdKEk

[Simile @simile_ai]

Read more in the New York Times: https://t.co/kiIfpDdKEk

[Simile @simile_ai]

Today we’re announcing our Series B.

We’ve raised $200M at a $2B valuation from Greenoaks with participation from Index Ventures, Hanabi, A*, Bain Capital Ventures, CVS Health Ventures, and Definition.

Our mission is to simulate all eight billion people on earth, accurately.

[Simile @simile_ai]

Simulation is a difficult and ambitious problem. We’re hiring researchers, engineers, designers, and operators to help build it. Join us: https://t.co/bA0vUxEIcx

[Sanjay Kairam @skairam]

I’m one month into @SimileAI, and I’m even more convinced that evals for simulating human behavior is one of the most interesting problems in AI.

That's why we’re growing our small-but-mighty Evals team by hiring multiple Evals -- MTS roles in SF + NYC.

https://t.co/cjqmbzmZly

[Mihika Kapoor @mihikapoor]

I’m hiring a video game designer @simile_ai

The first thing we ever built was a top-down pixel-art town called Smallville. It looked like a game, but the characters were the world's first ai agents living their own lives.

Now we're building simulated worlds full of people who act like people, and we want a website that feels like one too.

if you obsess over games, sprites, systems, worldbuilding, behavior, and making things feel alive, DMs are open :)

[Joon Sung Park @joon_s_pk]

Simulation and AGI were the twin pillars of advanced civilizations in all my favorite sci-fi. When we created Smallville and agents in 2023, the romantic in me couldn’t resist devoting my career to it -- now with an incredible team @simile_ai.

Fun conversation @sonyatweetybird!

[Toronto Tech Week @TOtechweek]

Our official main stage brings together 1,000+ of Canada's top builders from around the world.

Featuring @tobi @andrewgordonmac @nickfrosst @lucyhargreaves4 @Sirupsen @MaxBrodeurUrbas @ElainaYallen @EliotPence @mitrymin @Alex_Danco and more.

Limited in-person tickets. Request access ➡ https://t.co/U0lagZzuKv

[Percy Liang @percyliang]

I think it’s pretty clear that simulation is the next frontier for AI.

The most impressive feats of AI to date are when we have a clear environment + reward, whether it be beating Le Sedol at Go, winning an IMO gold medal, or writing entire apps from scratch. In these cases, the RL algorithm can try different actions, and observe the well-defined consequences in the safety of a docker container.

But what about messy real-world situations involving people? The rewards are unclear, the stakes are high, and you can’t experiment in the real world. But these situations are precisely where the next big opportunity in AI is. To crack this, we need to *simulate* society (“put society into a docker container”). Concretely, this means building a model that can predict what will happen in any given situation (real or hypothetical). If we can do this, we are only limited by our imagination: predict the future, optimize for better outcomes, answer hypothetical (“what if”) questions. Ultimately, this goes beyond making better decisions, but it’s about giving us a better understanding of ourselves and the world.

Simulation is the whole enchilada. And this is exactly the research that @simile_ai is working on. Read more here:
https://t.co/eBMW2beHdT

[Yann Dubois @yanndubs]

Simulating humans is such an interesting and useful problem but very comps, if anyone can do it it’s this team @joon_s_pk @percyliang @msbernst

[Simile @simile_ai]

Our work on generative agents showed that it's possible to accurately simulate human behavior by capturing rich information about real people.

@joon_s_pk spoke with @Nature about how our work builds on this research, and how enterprises can now use simulations to test decisions before they hit the real world:

https://t.co/5XswZaafif

[Joon Sung Park @joon_s_pk]

Exciting to see @WSJ cover what we’re building at
@simile_ai.

It’s great to see the technology we developed in the lab making real world impact alongside foundational institutions like CVS and Gallup. Nothing like frontier research meeting real PMF!

https://t.co/C2Dbre0p8y

[Simile @simile_ai]

Read more here: https://t.co/Xd8PumCnGK

[Simile @simile_ai]

Simile is increasing decision-making capacity and decreasing research time. We are proud to work with partners like @CVSHealth! 🤝

Projects that took months are now taking hours, and studies are closer resembling human behavior than prior self-reported research - all with the goal of providing the best products and services for customers at companies like CVS Health, where the customer is centered in every decision.

Read more in the CVS Health whitepaper below.