The Most Promising Startups From The First-Ever YC Spring Batch

“Make something people want.” That’s the famous Y Combinator slogan—and the results speak for themselves. Over the years, YC has launched some of the most iconic startups of our time, including Airbnb, DoorDash, Dropbox, Instacart, Stripe, and Deel.

Now operating four batches per year, Y Combinator just introduced its first-ever spring batch—and the upcoming Demo Day promises to deliver. Startups are working around the clock to prepare and attract investment from top-tier VCs.

What’s There For Us?

Unsurprisingly, many of the YC X25 (Spring 2025) batch startups are AI-driven—but their applications span a wide range of industries. From homebuying and healthcare to solopreneur support and developer tools, this batch reflects the growing diversity of AI use cases.

• Cactus is building the AI business assistant that empowers solopreneurs to succeed by handling calls, qualifying leads, and managing bookings, allowing them to scale with nearly no admin staff. In other words, an AI copilot for solopreneurs.
• Approval AI is transforming homebuying by using AI to automate the entire mortgage process, making it radically faster and simpler. One-click mortgage: AI shops, negotiates, and handles your application.
• Den, Cursor for knowledge workers, makes it 10x easier for anyone—not just engineers—to build and collaborate with AI agents on a Slack/Notion-like platform, unifying your entire productivity stack behind one natural language interface.
• SynthioLabs, is the world’s first AI medical expert for pharma GTM teams, enabling them to 3x their physician reach with always-on, personalized, and medically accurate engagement. By transforming how pharma connects with every physician—not just the top tier—SynthioLabs is set to revolutionize medical education, compliance, and outreach at scale.
• Text.ai brings AI directly into SMS, WhatsApp, and Telegram, letting over 5.5 billion people access powerful AI without downloads or a learning curve. By embedding AI where people already chat, text.ai is making advanced technology instantly accessible and collaborative for everyone, everywhere.
• Better Auth is the fastest growing auth library with 14k+ stars and 1.5M+ downloads. They let developers build secure, enterprise-grade authentication in TypeScript without relying on third-party services. This empowers teams to innovate faster while maintaining full control over their user data.

Solving Real Problems, One AI Breakthrough at a Time

Cactus is addressing the operational challenges faced by solopreneurs—particularly private chefs and other service-based entrepreneurs. These businesses often rely on multiple disconnected tools and consultants, making it difficult to scale and grow. With recent advancements in AI and voice technology, there’s a unique opportunity to automate and streamline these workflows. Cactus aims to be the AI Copilot that manages brand maintenance, website creation, lead qualification, proposal generation, and invoicing—freeing up solopreneurs to focus on what they do best.

Ajith Govind and Avinash Joshi, co-founders of Cactus, explain:

“The idea for Cactus emerged from personal experiences. We both became fathers and started working with private chefs. We saw firsthand the intense operational demands they faced. Those shared experiences and insights into the broader challenges solopreneurs encounter inspired us to launch Cactus.”

Ajith brings a strong foundation in data science and firsthand experience scaling a previous YC-backed company—giving him deep insight into business growth and operational pain points. Avinash’s engineering prowess and experience in building products for major companies like Unilever, Pepsi, and Nestle make him an invaluable asset.

Text.ai is consumer-first and AI-native. With no downloads required, Text.ai brings AI to where 97% of Americans already are multiple times a day: in their chats. And with collaborative AI features, Text.ai allows groups to plan trips, book restaurants, and set reminders—seamlessly and together.

Founded by three friends Rushi Shah, Prahar Patel, and Paras Maniar, Text.ai was born out of frustration with how tech often adds complexity instead of reducing it.

“I built the first version just for fun—as a personal travel companion to help me find hidden vegetarian restaurants while backpacking solo in Spain and Portugal,” Rushi recalls. “It was ridiculously simple but solved a real problem. Then friends started asking to add the AI to their group chats. The magic? No one had to download a thing. AI just showed up where they already were.”

Arjun Lalwani and Helly Shah, co-founders of Approval AI, are tackling one of the most frustrating parts of homeownership: the slow, opaque, and stressful mortgage process. “The mortgage process in the U.S. is broken,” Arjun says. “Rates aren’t transparent, paperwork is repetitive, and buyers are bombarded with lender spam before they even understand what they’re signing up for.” As first-time homebuyers—with technical backgrounds—they found the process confusing, inefficient, and severely lacking in transparency. That personal pain inspired the creation of Approval AI, which uses AI to streamline and simplify the mortgage journey for others.

The founding team blends deep technical expertise with hands-on industry experience. Arjun built large-scale commerce products at Google, including YouTube Shopping. Helly comes from a multi-generational real estate family and has experienced the mortgage process from every angle: as a developer, broker, and buyer. She’s a licensed mortgage broker, a former software engineer at Google Maps, and previously built real-time trading systems at Goldman Sachs.

Bereket Engida, Co-Founder and CEO of Better Auth, is on a mission to solve one of the oldest—and still unsolved—problems in software: authentication. Deeply embedded in the TypeScript ecosystem, Bereket has built a wide range of apps and open-source libraries. Now, alongside co-founder KinfeMichael Tariku, he’s developing a comprehensive, framework-agnostic authentication solution built specifically for TypeScript.

“Even though auth is one of those age-old problems,” Bereket says, “it’s still surprisingly only half-solved. It continues to be a pain to implement, and as a developer myself, I’ve felt that pain over and over again. It’s not that there aren’t options—it’s just that the choices aren’t great.”

The goal is to empower developers to build secure, enterprise-grade authentication systems without relying on third-party services—giving teams full control over user data while accelerating innovation.

Justin Lee and Linus Talacko are building Den with a bold vision: to make AI agents accessible and useful for all knowledge workers—not just engineers. The idea began when Linus, then CTO and co-founder of Lyrebird Health (one of Australia’s fastest-growing startups), saw firsthand the productivity gains engineers were achieving with tools like Cursor and Windsurf. But when it came to non-technical teams, existing solutions like Slack’s Agentforce and Relevance AI fell short. Frustrated, Linus started building internal agents for his entire company. What began as a side project quickly evolved into a new mission.

Justin stepped in and convinced Linus to embark on a 20+ year journey to fundamentally reshape how knowledge work is done. Their long-term vision? Teams of 10 orchestrating swarms of 1,000+ AI agents—freeing up human talent to focus on creativity, judgment, and decision-making. Their mantra: empower the first 10-person unicorn. Inspired by platforms like Shopify and Atlassian that provide infrastructure for others to build on, Den aims to become the superstructure for AI-native teams to scale smarter and faster.

Supreet Deshpande, Sahitya Sridhar and Rajashekar Vasantha, co-founders of SynthioLabs, are building voice AI medical reps for pharma commercial and medical teams to engage with their most important stakeholders—doctors and patients. Pharma spends billions annually on sales and medical representatives, yet most physicians—especially those in community settings, who make up the majority of the market—never hear from one. The result? Missed engagement, slower adoption, and lost revenue where it matters most.

SynthioLabs is building voice AI medical reps that help pharma scale physician engagement in ways traditional field teams cannot. Their AI reps deliver compliant, on-demand medical info —and capture rich data on physician needs and concerns at scale.

The team includes ex-McKinsey and ex-ZS life sciences experts, as well as AI researchers from AWS. They have worked with 10 of the top 20 pharma companies and bring over a decade of experience in life sciences.

The YC Effect

These companies are about to present their ideas on Demo Day this week—the moment they’ve been working tirelessly toward. But what have they learned along the way? And how has their vision evolved since the beginning?

“The community”, says Justin Lee, Co-Founder of Den. “Unmatched loyalty, generosity, and ambition.” He adds, “It feels like having the entire world at your back—from GPs to batchmates.” Den’s company vision has evolved significantly: from a no-code, multiplayer agent builder for non-engineers to building an Agent Marketplace for sharing and selling agent workflows.

Supreet Deshpande, Co-Founder and CEO of SynthioLabs highlights, “Honestly, the best part about YC is the pace and the clarity it brings.” Founders are pushed to move fast, cut out the noise, and make decisions in days rather than months. And, of course, there’s the “founder energy.”

When they started, SynthioLabs focused on using AI to help pharma companies reach more physicians—especially those often overlooked. But as they went deeper, they discovered a bigger opportunity: bringing consumer-grade customer obsession to pharma. Now, they aim to become the platform for all customer engagement in pharma, closing the gap between what physicians and patients expect as consumers—and what they currently experience from the industry.

Going through Y Combinator has been instrumental for Cactus, primarily by driving focus on achieving product-market fit. “However, one of the most underrated benefits is the belief factor,” says Ajith Govind. “It instills confidence in founders to aim higher—to see themselves as the next big success story, like Airbnb.”

Cactus originally launched as a marketplace connecting private chefs with families. But the founders quickly realized the real challenge was not the connection—it was what happened afterward. That insight led to a pivot: Cactus now builds AI-powered business automation tools. The company’s new vision is to develop an AI Copilot that runs an entire business on autopilot—freeing up solopreneurs to focus on what they do best and capture more opportunities.

Rushi Shah, CEO of text.ai, puts it simply, “The best thing about Y Combinator is speed and focus.” He adds, “In ten weeks, we 10x’d our user base, stayed laser-focused on product development, and pushed ourselves to get more done every week—regardless of company size, funding, or stage.”

As Demo Day approaches, one thing is clear: this generation of YC founders isn’t just building companies—they’re reshaping industries. Fueled by urgency, guided by clarity, and supported by one of the strongest founder communities in tech, these startups are turning ambitious ideas into scalable, world-changing products. Whether it’s simplifying mortgages, reimagining healthcare engagement, or putting AI in the hands of solopreneurs and everyday users, the YC spring batch (X25) is a glimpse into the future—faster, smarter, and more founder-driven than ever.