Bret Taylor

Sierra has opened an office in Toronto, and we’re hiring! 🇨🇦 sierra.ai/blog/sierra-la…

At Sierra, we’ve built a transcription platform that dynamically routes across providers, incorporates a customer’s context, supports 70+ languages, and adapts to real-world variability, improving both agent effectiveness and customer satisfaction sierra.ai/blog/voice-ai-…

An OpenAI model has achieved a major breakthrough in mathematics, by disproving a central conjecture in discrete geometry that was first posed by Paul Erdős in 1946. This is the first time AI has autonomously solved a prominent open problem central to a field of mathematics.

Sierra for branded credit cards: Imprint built a single agent that transforms into Booking, Shell, Rakuten—whichever brand is on the card—and got their sponsoring banks to sign off on it. Not a decision tree, but an intelligent agent that reasons, selects tools, and passes audits. sierra.ai/customers/impr…

R1 sits at the intersection of providers, payers, and patients, handling the revenue cycle — everything non-clinical — on behalf of health systems across the country. In partnership with Sierra, the R1 AI agent is already resolving 40% of incoming calls sierra.ai/customers/r1-r…

Grateful that Sierra is partnering with @dhivyasu and Fiserv to replace IVR systems and hold times with delightful agents for the thousands of banks and millions of people who depend on Fiserv for payments infrastructure

Paychex pays one in eleven private sector workers in the United States. With Sierra, Paychex rethought payroll processing to deliver 24/7 service with 95% customer satisfaction sierra.ai/customers/payc…

Introducing the latest agent benchmark from Sierra, 𝜏-knowledge. Most benchmarks test either an agent's ability to find information, or take action. 𝜏-knowledge tests both at once. sierra.ai/blog/tau-knowl…

At BARK, the world’s most dog-centric company and the team behind BarkBox, customer experience isn’t a department, it’s the business. I'm proud they've chosen to partner with @SierraPlatform to power their customer experience sierra.ai/customers/bark

Happy Mother’s Day 💐💕

@thygesen_allan @claybavor Allan, thank you so much for our partnership

@btaylor Congrats, @btaylor and @claybavor . Excited to be working with you.

Sierra is raising $950 million from new and existing investors, led by Tiger Global and GV, at a valuation of over $15 billion. We now have more than $1 billion to invest in becoming the global standard for companies wanting to transform their customer experiences with AI.  We’ve never had such conviction in the opportunity for Sierra and our customers. Just a couple of years ago, we had four design partners. Now, Sierra is serving over 40% of the Fortune 50, and agents built on our platform are powering billions of customer interactions — everything from refinancing homes to processing insurance claims, returning orders, and helping people raise millions in fundraisers. We’re deeply grateful to our customers for helping show what’s possible. If you’re not yet using Sierra, we’d love to partner with you. sierra.ai/blog/better-cu…

@mikebid Thank you for your partnership!

@btaylor Congrats @btaylor and Sierra team! As a customer, love what you’ve built and rooting for you all

The Sierra research team has contributed many of the leading industry benchmarks for agents grounded in our ambition to have the most robust and sophisticated agents in customer experience. 𝜏-voice is our new benchmark for real-time voice agents. 𝜏-voice measures 278 grounded customer service tasks across retail, airline, and telecom. It pairs deterministic, end-to-end task scoring with realistic, controllable audio across diverse personas, environmental noise, and free-form turn-taking. sierra.ai/blog/tau-voice…

1. We believe in iterative deployment; although GPT-5.5 is already a smart model, we expect rapid improvements. Iterative deployment is a big part of our safety strategy; we believe the world will be best equipped to win at the team sport of AI resilience this way. 2. We believe in democratization. We want people to be able to use lots of AI; we aim to have the most efficient models, the most efficient inference stack, and the most compute. We want our users to have access to the best technology and for everyone to have equal opportunity. We have been tracking cybersecurity as a preparedness category for a long time, and have built mitigations we believe in that enable us to make capable models broadly available. 3. We love you and we want you to win. We want to be a platform for every company, scientist, entrepreneur, and person. (My whole career has largely been about the magic of startups, and I think we are about to see that magic at hyperscale.)

Introducing GPT-5.5 A new class of intelligence for real work and powering agents, built to understand complex goals, use tools, check its work, and carry more tasks through to completion. It marks a new way of getting computer work done. Now available in ChatGPT and Codex.

We're excited to announce that Sierra has acquired Paris-based Fragment, which helps businesses scale their operations using AI. Fragment's cofounders are passionate about building better, more human customer experiences with AI, and bring valuable strength to our agent development efforts in France.

As coding agents have become the standard for developing software, we've transformed Sierra's engineering interview process to be AI-native. We've documented our lessons here, and very curious how others in the industry are navigating sierra.ai/blog/the-ai-na…

Introducing μ-Bench, an open multilingual transcription benchmark. At Sierra, we benchmark 79 locale variants across 42 languages and 13+ providers. Today, we're open-sourcing a subset of that evaluation as μ-Bench, which we hope will help labs improve real world transcription quality sierra.ai/blog/mu-bench-…