Top Tech Startups in California, US in 2026

Prime Intellect democratizes AI development at scale. Our platform makes it easy to find global compute resources and train state-of-the-art models through distributed training across clusters. Collectively own the resulting open AI innovations, from language models to scientific breakthroughs.

Karlon Group provides enterprise-grade fractional finance & accounting, data analytics and investor relations support services to bootstrapped, venture-backed, and private equity owned companies at various stages of growth. We bring decades of strategic and operational finance & accounting experience, partnering with businesses across a range of industries, from SaaS to consumer to financial services. Our fractional CFO franchise prioritizes close partnership, excellence, and integrity above all in our approach to advising clients on their most critical finance & accounting challenges.

We're an early stage security startup founded by 2 experienced technical leaders from Tessian (former Head of Eng and former Lead Architect). Our product helps security teams quickly and accurately detect intrusions in their cloud environment using canaries. We're Series A stage and about to ramp up the company from 24 to 32.

Agentic Operating Procedures for your ERP. Execute at machine speed, learn from every exception, and improve with every transaction.

Parker is the AI creative director built to produce the highest-performing ads on the internet. Every company needs to grow. That's not new. What is new is that AI is about to create more companies than the world has ever seen, and every single one of them will eventually need to find customers. That problem isn't going anywhere. If anything, it's getting bigger. There are thousands of ad agencies built to solve it. A handful are great. Most are honestly pretty bad. And none of them scale past the people who work there. The idea behind Parker is simple: what if there's one agency that's as good as the best in the world, except it runs in software instead of people? We launched. We went viral. We've grown 10x since January. Top brands like LiquidIV, Gruns, and Legends now rely on Parker to create ads that actually win. We're not building just another AI tool. We're building the default answer to the question every company eventually asks: who's going to help us grow? We're a small team of people who deeply love their craft. Engineers who love to build, creative strategists who live for a great ad, and marketers obsessed with growth. We don't just work on this. We love what we're working on. If that sounds like you, we'd like to meet you.

Amigo partners with healthcare organizations to deploy robust AI infrastructure that directly serves patients and providers. Our agents handle clinical workflows and patient engagement across the entire journey: pre-visit intake, care navigation, post-visit care plans, patient monitoring, and more. We own outcomes, not just delivery. For our customers, we're responsible for agent performance: clinical safety, continuous improvement, measurable patient outcomes. Agents operate autonomously within bounded clinical domains, with clear scope and handoff protocols. That scope expands as we validate performance across populations. We're backed by Tier 1 investors like General Catalyst, GSV Ventures, SVA, and CohoVC. Our work is validated with leading academic medical institutions. Our agents have reached 3M+ patient encounters and are on track to 10x this year.

FleetWorks automates the 2B phone calls and emails that the freight industry makes every year. We use voice synthesis, generative AI, and integrations with logistics systems to solve the largest cost in this industry - people. We are a fast-growing startup in the logistics space led by a founding team from companies like Airbnb and Uber Freight. We are a YC backed company. For more information about us, visit ycombinator.com/companies/fleetworks