Braintrust has raised an $80M Series B.
We're building the infrastructure that helps teams measure, evaluate, and improve their AI products.
Don't take our word for it. Hear how @NotionHQ, @Vercel, @Navan, and @billcom use Braintrust to ship quality AI.
watching @braintrust operate over the last 2.5 years has been a privilege, and seeing the amazing products their customers have built even more so
excited to be quadrupling down in this round 😊
.@braintrust is building the infrastructure for production AI. We're very excited to be backing their Series B.
CEO Ankur Goyal joined a16z's Martin Casado to cover how systems engineering stacks up against the bitter lesson, why Chinese models are gaining ground faster than spending suggests, whether AI demand will eventually saturate, and more.
00:00 Introduction
03:10 What "evals" actually mean (hypotheses and the scientific method)
07:34 AI is continuous, systems are discrete
08:29 The bitter lesson: universal function approximators vs. engineering
11:58 Engineering the harness, not the model
17:47 Chinese models: high token usage, low dollar share
20:37 Why open source models aren't dominating yet
27:08 Frontier labs, infinite capital, and scaling limits
30:38 Demand-side saturation: enterprises can't absorb better models
38:47 Bash vs. SQL for agents: "the results are comical"
@ankrgyl@martin_casado
We sent this note to our customers to let them know that Braintrust has raised a new round of funding, and thank them for their support. While the money is exciting, our focus hasn't changed: we're building Braintrust to help our customers ship quality AI products.
In 2026, AI is moving to production but teams have never had less conviction about what will fail next. Our customers are building AI products that serve millions and simply need to work. If Braintrust makes their lives easier and their products better, I know we are doing our job.
Thank you to @ICONIQCapital for leading our Series B, and to @a16z, @GreylockVC, @basecasevc, and @eladgil for doubling down. Thank you to the Braintrust team for all the incredible work you've done over the past year. And thank you to our customers, who have made this growth possible.
Trace talk → @replit
On Feb 25, @pirroh takes the stage to discuss agent observability at scale with @ankrgyl. If you're in SF, come: https://t.co/ZCIWsXyMSd
Announcing Lovable raised $330M at a $6.6B valuation.
We launched Lovable to empower the 99%, the people with ideas who don’t code.
Now everyone is a builder: founders, teachers, artists, and teams inside the world's largest companies.
Meet some of those incredible builders:
We're hosting a zero bullshit conference on evals & o11y for AI products.
Trying to focus on ppl actually building stuff sharing learnings with each other.
If you're building an AI product, would love to see you there!
Trace, our first user conference, is on Feb 25 at the California Academy of Sciences in SF.
500 AI builders. Hands-on workshops. Live demos. Sessions taught by the teams actually shipping production AI.
Save the date → https://t.co/HYtitZZyIq
Super excited that Loop is now GA. Loop brings frontier AI to AI dev and helps you write/optimize prompts, search through logs to find/categorize issues, and even generate synthetic data.
It's also been a helpful to dogfood building a complex agent 🧵
@eurowings@eurowings it doesn't work: "There was a problem in finding your details. No record was found with that reference number and family name combination. Check the values entered and try again."
These are the right details though - I have an email confirmation with my case reference
@eurowings I lost my bag on one of your flights, I'm getting an error message when using your self-serve portal (https://t.co/XZEDc8evwu), your hotline says they can't help me, and the email they provided bounces. Please help!!!
@Kiehls - I've made an order on Nov 29. The package was not delivered to my address and returned to your warehouse. I requested a new delivery which wasn't possible. I still haven't received the refund even though I reached out to your support team on Dec 15. Please get in touch.