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.

Itaú used Simile’s behavioral simulation to turn a five-week research cycle into four days and a two-week concept exploration into under three hours. The work also won an ESOMAR Award for AI and automation in market research. simile.com/blog/itau-at-esom…

What does it take to build an AI model that can accurately simulate human behavior? You need to understand both what people do and why they do it. On Sept 24, @msbernst is taking us under the hood of behavioral simulation. We’ll explore why neither behavioral data nor surveys and interviews are enough on their own, what each reveals about human behavior, and how Simile brings them together to model what people might do next. RSVP here simile.zoom.us/webinar/regis…

Me to @msbernst last year: What if we build a simulation company together

I describe AI behavioral simulation as a “what-if” machine. I wrote about what a What-If Machine is, and how it works, at @simile_ai:

Most big decisions are some version of a “what-if” question. What if we launched this? What if we raised the price? What if we didn’t? At Simile, we’re building a What-If Machine to simulate those decisions before making them for real. But getting the answer right requires understanding both what people do and why they do it. @msbernst explains what it takes to build one. simile.com/blog/what-if-mach…

Simile has been selected amongst this year's IA40, the top private companies shaping the future of applied AI. Proud to be building alongside this group.

The story behind Simile, the research that started it all, and what we’re building today! Thank you @kateparknews for the thoughtful conversation.

Anyone can simulate the future. But the simulation only matters if it’s trustworthy. At Simile, we train two types of models: simulation models and confidence models. Our first research blog post explores the origin of our proprietary confidence model, which predicts the accuracy of our population simulations and, in turn, makes them actionable. simile.com/blog/confidence?v…

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?

Series B @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. nytimes.com/2026/07/30/busin…

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. jobs.ashbyhq.com/simile/33d7…

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 :)