Discover the next generation of startups.

Litmus

YCombinator

Run an async work trial on every engineer you interview.

Litmus is the most accurate read on how an engineer actually builds. We evaluate candidates through async technical assessments built from your own tech context (repos, tickets, and job descriptions), generated from scratch and scoped as real end-to-end features. Candidates work in their own setup with all their tools including AI, while we track and evaluate their process and output. Every submission runs in a sandbox, and grading is tuned to your company across tool fluency, process, and outcome. You get a real read on how someone actually builds, not just how they interview.

Lob

YCombinator

Lob is the only automation platform that transforms direct mail into…

Lob provides the building blocks for developers to automate the offline world. Enterprise companies use Lob’s suite of APIs to mail fully dynamic and personalized customer communications with print media. We provide insight into deliverability with piece-by-piece tracing and utilize our proprietary Print Delivery Network to streamline production across fully redundant nodes all over the country. Founded in 2013 and based in San Francisco, Lob is venture backed by Y Combinator, Polaris Partners, Floodgate, and First Round Capital. Find out more about Lob and what we’re up to by following our blog: https://lob.com/blog or visiting our website: https://lob.com.

Locata

YCombinator

AI Referral Automation for Primary Care Clinics

Locata is an AI referral management platform for Primary Care. We deploy AI agents to automate every step of the referral process that back-office staff face daily, from submitting prior authorizations to broadcasting updates and following up with patients. This frees up staff to focus on patient care. Primary care back-offices are severely understaffed and overburdened by administrative work associated with referrals. Additionally, patients suffer navigating the complex referral process, which can have disastrous health effects if they don’t get the care they need. These factors point to a glaring gap in the system—where out of over 100 million specialist referrals issued annually in the US, only half are actually completed. Locata is tackling this problem head-on, saving administrative staff hours each week and ensuring that the referral process goes as smoothly as possible for patients and their providers. Alejandro and Josh met at Stanford where they graduated with BS degrees in Computer Science. Alejandro was a senior software engineer at Meta’s Reality Labs where he led development of several AI features for wearable products and prior to that conducted AI research at Stanford Medicine. Josh graduated with a masters in Computer Science, specializing in AI, before working as a software engineer at Google where he developed AI products that served over 1 billion users. Within two weeks of building our product, we signed a major regional health center and have saved them over 100 hours of work in our first month live.

Locus

YCombinator

Payment infrastructure for AI agents

We make your agents pay. As agents evolve from tools into dependable, autonomous actors, they’ll need the ability to execute open-ended workflows end-to-end. This inevitably means payments: accessing paywalled data, transacting for services or with other specialist agents. But autonomy requires guardrails. Businesses and developers will need a way to ensure their agents only spend how much and on what they’re supposed to. The machine economy is coming, and Locus (YC F25) is building the connector businesses will need to participate. We connect agents securely to funds, letting you define permissions and limits for every transaction. Each payment is traceable, auditable, and fully reconcilable with your existing financial stack.

LogosGuard

YCombinator

The sensitive data redaction layer for AI

Use AI tools like ChatGPT, Claude, and Gemini safely without leaking sensitive data. LogosGuard redacts your private information before the prompt ever leaves your device.

Lollipuff

YCombinator

Online Auctions for Authentic (Women's) Designer Goods

Lollipuff is the only online auction site that pre-screens each and every item to guarantee the authenticity of its high-end, pre-owned designer apparel and accessories. Buyers can be confident they're getting the real deal, and sellers never have to worry about listing their luxury pieces alongside counterfeits. Combining the buyer security of an upscale boutique with the amazing prices of an online auction, Lollipuff is the go-to site for authentic, affordable and on-trend designer fashion.

Lua Global Inc

YCombinator

The mid-market agent platform

Lua is the mid-market agent platform. We deliver enterprise reliability with the speed, flexibility, and economics that mid-market companies demand - helping them deploy AI agents that drive sales, support, and operations across everyday channels and tools. We scale through developer agencies and channel partners, enabling rapid distribution without a large enterprise sales motion or scaled forward deployed teams. We think of Lua as an agentOS that abstracts all of the complexity required to launch enterprise grade agents and combine it with the tools needed for these agents to succeed in the real world. Lua was founded by Lorcan O Cathain (CEO) and Stefan Kruger (CTO)- experienced founders who have spent 15 - 20 years each scaling technology companies across emerging markets. We sell to mid-market enterprises and developer agencies in the US and internationally. Developers are increasingly our primary ICP but we run SMB & enterprise sales motions to accelerate our learnings and further develop our product: - SMB ($25- 1k per month): fully automated self-serve agents that handle sales and support for eCommerce companies, hotels, restaurants and general service businesses. If you’ve been on our website you’ve likely seen this. - Enterprise: We directly sell to mid-market (~ $50M- $1BN) businesses across the US and internationally to eat our own dog food and strengthen our platform.

Lucent

YCombinator

AI that automatically improves products from user behavior

Lucent is an AI product manager that automatically improves products based on how users behave. We use AI to watch and understand user sessions and detect bugs and UX issues.

Lucira Health

YCombinator

Next generation infectious disease test kits

Diassess Inc. is revolutionizing the way infectious diseases are prevented, diagnosed, and monitored by developing the tools necessary to empower people to become knowledgeable about their health. We produce inexpensive, disposable health diagnostic hardware that transforms any smartphone into a portable, real-time health-monitoring device for rapid, accessible, multiplexed analysis of bodily fluids anywhere in the world.