Y Combinator Companies: Top YC Startups & How to Get Into the Program
By
Ethan Fahey
•
Nov 25, 2025
Y Combinator has launched some of the most influential startups in tech, including Airbnb, Stripe, and Coinbase. If you’re curious about the standout companies that have come through YC, or you’re thinking about applying, there’s a lot to learn from their trajectories and what sets them apart. If you’re building or scaling an AI-focused business, Fonzi AI can support you by connecting you with top engineering talent and offering tools to help your startup operate more efficiently as you grow.
Key Takeaways
Y Combinator is a leading startup accelerator that provides funding, mentorship, and a supportive alumni network, significantly improving startup success rates.
The program operates biannually funding cycles, offering startups competitive opportunities to gain invaluable resources and showcase their ideas.
Emerging companies like Notable Labs and Fonzi illustrate Y Combinator’s ongoing innovation, focusing on personalized medicine and efficient AI talent acquisition.
Y Combinator: A Startup School for Innovators
Y Combinator is a beacon of innovation, a startup accelerator and fund that has redefined the entrepreneurial landscape. Its mission is to help founders create products people want, significantly improving the success rates of startups through Y Combinator’s program, Combinator Partners Co.
Offering seed investments and mentorship, Y Combinator has built a legacy as a premier startup accelerator, with its companies’ combined valuation exceeding a staggering $600 billion, and many have had their successes fueled by its investments. Additionally, companies looking to grow often seek investments from Y Combinator.
The Genesis of Y Combinator
Founded in March 2005, Y Combinator made its first investments in the same year, planting roots in Mountain View, California. This startup school was envisioned as a nurturing ground for startup founders, providing them with the resources and support needed to transform their ideas into successful businesses.
The founders’ vision was clear: they decided to create a project where innovative ideas could flourish with the right guidance and funding, as envisioned by the co-founder, Paul Graham.
Why Startups Thrive with Y Combinator
Startups thrive at Y Combinator because of its unique blend of support, mentorship, and funding. The YC batch program is designed to assist founders in developing their ideas and raising funds. Key aspects include:
An initial investment covering essential expenses, allowing founders to focus on their business
Support from experienced mentors
Access to a vibrant alumni network
This environment not only fosters growth but also provides startups with a significant fundraising advantage.
How the Y Combinator Funding Cycles Work
Y Combinator operates on a biannual funding cycle, typically occurring in the spring and fall. These cycles offer startups two opportunities each year to secure funding and mentorship, navigating a competitive application process that selects the most promising ideas.
Selected startups gain access to invaluable resources, mentorship, and networking opportunities in marketing, propelling them towards growth and success.
Top YC Companies in 2025
The legacy of Y Combinator’s program is vividly illustrated through the success of its alumni. From revolutionizing the finance industry to transforming travel and logistics, YC companies have made significant impacts across various sectors.
Here’s a look at some of the top YC companies in 2025.
Stripe
Stripe, founded by Patrick and John Collison in 2009, has become a cornerstone in the payment processing industry. Key points about Stripe include:
Valuation reaching $70 billion in 2024
Supports over 300,000 business clients through its subscription-billing service
Acquired Bridge, a cryptocurrency infrastructure software company, for $1.1 billion, further solidifying their market position.
During the 2024 holiday shopping period alone, Stripe processed transactions exceeding $31 billion, highlighting its pivotal role in the financial ecosystem.
Airbnb
Airbnb, the brainchild of three innovative minds, has transformed the global travel industry. Key facts about Airbnb include:
Over 8 million active listings
Diverse accommodations for travelers worldwide
Hosts have generated a total of $250 billion in earnings, reflecting the platform’s significant economic impact.
In 2023, Airbnb reported diluted earnings per share of $7.52, showcasing its strong financial health and continued growth.
Coinbase
Coinbase was founded in 2012. Its mission is to enhance economic freedom for over 1 billion individuals. Achieving the milestone of becoming a Fortune 500 company in 2022, Coinbase now supports 110 million customers and facilitates transactions for more than 240 cryptocurrencies. This remarkable growth underscores its role in the evolving landscape of digital finance.
DoorDash
Founded in 2013, DoorDash:
Connects customers with local and national restaurants across more than 600 cities.
Holds a significant 67% market share in the United States food delivery sector as of March 2024.
Boasts 7 million active couriers.
This extensive network enables efficient food delivery, making DoorDash a leader in the industry.
GitLab
GitLab, founded in 2011 and joining Y Combinator in 2015, has redefined the work model by becoming the world’s largest all-remote company by 2020. Recognized by Gartner as a Leader in the Magic Quadrant for DevOps Platforms in 2023, GitLab’s platform enhances efficiency throughout the software development lifecycle. This recognition underscores its significant growth and industry standing.
Emerging YC Companies to Watch
While the top YC companies have already made their mark, emerging startups continue to innovate and disrupt various industries. Y Combinator’s intensive three-month accelerator program fosters a highly motivating atmosphere, driving productivity and innovation among startup founders in the YC Growth Program.
Here are a few emerging YC companies to keep an eye on, including one notable YC company.
Notable Labs
Notable Labs is at the forefront of developing personalized cancer treatments tailored to individual patient needs. Their innovative platform tests drug combinations specifically on individual cancer cells, optimizing personalized cancer therapies through unique scientific methodologies. This approach holds immense potential for revolutionizing cancer treatment.
Momentus
Momentus, selected for NASA’s Venture-Class Acquisition of Dedicated and Rideshare (VADR) contract, provides services including point-to-point delivery of payloads and a hosted payload platform for various space missions. Recognized for its pioneering technology, Momentus leverages water plasma propulsion to enhance efficiency in space operations. This technology could be a game-changer in space transportation.
Ginkgo Bioworks
Ginkgo Bioworks is revolutionizing biotechnology through the engineering of organisms for a multitude of applications across different industries around the world. Utilizing software and automation in large-scale organism design, Ginkgo Bioworks is recognized as a leader in biotechnology. Their innovative approach has the potential to transform numerous sectors.
How to Get Into Y Combinator
Securing a spot in Y Combinator’s program is a dream for many startup founders. With two funding cycles each year, the application process is highly competitive. However, with the right preparation and strategy, you can enhance your chances of success.
Here’s a guide to help you navigate the process.
Crafting a Winning Application
Founders must clearly articulate their vision and the uniqueness of their concept for users. Avoid jargon and focus on presenting a clear and concise description of your startup. Including an engaging video pitch can also help your application stand out.
Remember, Y Combinator accepts a small percentage of applicants, so make your case compelling.
Preparing for the Interview
The interview process is pivotal for founders to pitch their ideas and demonstrate their potential. Articulate your vision, address the problem you’re solving, and showcase your team’s qualifications.
Leveraging alumni networks for insights and advice can significantly enhance your preparation and chances of success.
Leveraging Alumni Networks
Engaging with Y Combinator alumni can provide critical insights and mentorship. Alumni networks offer unique perspectives on overcoming challenges faced during the YC program and can open doors to potential partnerships. Building and maintaining these connections can provide ongoing support and networking opportunities well beyond the application process.
Fonzi: Revolutionizing AI Talent Acquisition
In the realm of AI talent acquisition, Fonzi stands out as a game-changer. Connecting companies with elite AI engineers through a structured hiring event, Fonzi transforms the traditional job search into a transparent and efficient process.
Here’s how Fonzi is changing hiring for the better.
What is Fonzi?
Fonzi organizes a monthly event called Match Day, where companies can make salary-backed offers to candidates within a limited hiring window. This curated AI engineering talent marketplace employs high-signal evaluations to streamline candidate assessment, ensuring effective matching of applicants with jobs that best suit their skillsets.
Participating in Match Day allows companies to find top-tier, pre-vetted AI engineers, transforming the hiring process for the team.
Benefits for Startups and Enterprises
Fonzi provides startups and large enterprises with access to top-tier AI engineers, significantly reducing hiring times and improving the quality of candidates sourced. The platform supports both early-stage startups and large enterprises, making hiring fast, consistent, and scalable.
With most hires happening within three weeks, Fonzi enhances recruitment processes, allowing companies to extend verified salary-backed offers directly to candidates.
Elevating Candidate Experience
Fonzi ensures a superior candidate experience by providing personalized support through a Concierge Recruiter. The platform’s structured evaluations and bias auditing promote fairness and equality.
Enhancing the candidate experience ensures Fonzi provides engaged and well-matched talent, transforming hiring.
Summary
Y Combinator’s program has been a launchpad for some of the most successful startups in the world. From Stripe and Airbnb to emerging companies like Notable Labs and Momentus, the impact of YC is profound. Aspiring founders can learn from these success stories and utilize the insights provided to enhance their chances of joining this prestigious accelerator. With innovative platforms like Fonzi revolutionizing talent acquisition, the future for startups looks brighter than ever. Embrace the journey, leverage the resources, and transform your visionary ideas into reality.
