Software Team at Y Combinator

Y Combinator (YC) provides seed funding for startups. YC works with founders to help them with their company ideas and deal with investors and acquirers. To date, we have funded 1,500 startups and they are worth more than $70 billion in total. Our mission is to enable the most innovation of any company in the world and to spread that innovation throughout the entire population.

Job Openings at Y Combinator

Top Engineering Values

Each team is asked to select, explain, and rank their top 8 values in order of importance.
  • Start-to-Finish Ownership

    We encourage the entrepreneurial spirit within our software team, just as we do for the founders in each batch.

    Startup School is a great example of what one engineer can build at YC (good work, Finbarr). Startup School required close work with YC’s President, Sam Altman and Steven Pham (who works on special projects) to spec out the software, define what a YC MOOC should look like, and structure the program using software. For those who aren’t familiar with Startup School, it is a collaboration with Stanford University that combines lectures and hands-on office hours to teach founders about launching startups. Companies are invited to apply to participate in the MOOC. Companies that are accepted are split into groups and assigned a YC alumni to advise them as they learn from the course material and submit weekly metrics about their companies. At the end of the class, just like YC, they have a Demo Day. But unlike YC’s, MOOC Demo Day is virtual since these founders are working from all over the world.

    Project ownership is more than code development. As you can imagine, developing Startup School involved collaborating with others to design course material, build software from scratch to run the course, and participation in the course to support the enrolled founders; sometimes offering technical advice for their startups and other times providing technical support and building new features.

    The entrepreneurial spirit at YC extends to its internal engineering team. The possibilities are endless and creativity and experimentation are encouraged. While you aren’t required to invent new projects yourself, we will support the ideas you develop. One of our engineers, for example, put together a series of conversations for the YC blog called Ask A Female Engineer where female engineers answer questions posed to them by readers.

    Get in touch if you want to know more!

  • Customer Comes First

    Everything we build supports our YC founders and partnership.

    While our customer base of YC partners and founders is small, they are a critical group of users. Our software supports everything we do at YC: founder applications, our public recommendation system where anyone can recommend a startup, the Startup School MOOC, our social network for founders called Bookface, our Demo Day software, and of course, Hacker News (though HN is run by a separate team of LISP hackers).

  • Ideal for Parents

    We provide 4 months parental leave for men and women, as well as YC baby onesies.

    We are incredibly supportive of our current and soon-to-be parents. Along with our paid family leave policy, we also do our best to accommodate new parents in whatever way we can. For instance, we transformed one of our Mountain View offices into a lactation room for one member of the YC team after she had returned from her maternity leave. Our vacation policy allows parents and non-parents alike to take 3 consecutive weeks off, though we encourage you to consider demo day and other scheduled events when you do. When you join YC, you will be encouraged to live a balanced and productive life and provided the independence to figure out what that means for you.

  • Flat Organization

    We tend to hire self-motivated individuals who enjoy working independently.

    At YC, partners are our version of executives and our engineering team works directly with them. One of the partners runs the software team at a high level and the team of 4 reports to him. Different partners focus on different parts of the organization, so depending on what kind of software you’re building (e.g. admissions or financial software), you’ll work with different people (e.g. the admissions team or our CFO and the finance team, etc.). The software team members do weekly 1-1s to talk about how things are going and to identify areas for improvement, but ultimately, our team is very flat, which allows each person to run with their ideas and projects. People at YC tend to be independent and self motivated. Once you’re assigned a project, you have the opportunity to get creative and work with your customers to spec, prototype, build, release and promote it. When you have an idea about how to improve YC, you’re encouraged to pursue it.

  • Creative + Innovative

    We are constantly experimenting and thinking about how to scale YC.

    The software team is continually collecting feedback from YC founders, partners, and employees. A big part of our job is figuring out how to scale YC, improve the founder experience, increase the number of startup applications, and better support our alumni community. Once a month, the software team meets for a few hours to brainstorm about which projects will bring the most value and drive our organization’s key metrics. New initiatives are born from these meetings, like building our public recommendation software, which encourages people to apply to YC. We are always looking for new ways to get the word out about YC and encourage people who might not otherwise start a company or apply to do just that.

  • Impressive Team Members

    The YC founder ecosystem is made up of people from all over the world that are passionate about everything from supersonic jets to fashion.

    Working at YC means working with an incredibly smart, knowledgeable, and interesting group of individuals. The ability to learn with and from one another is likely one of the best perks about working at YC. Our partnership has deep expertise starting, growing, and running companies. To name a few, our CEO Michael Seibel was the founder of two YC companies: and Socialcam. Our CFO Kirsty can tell you anything you need to know about financing a company or fundraising. YC’s General Counsel Carolynn invented the SAFE, a convertible investment type that’s become an important part of startup investing. Paul Buchheit is the creator of Gmail. Ali Rowghani, the partner who runs our Continuity fund, was formerly the CFO of Pixar and COO of Twitter. The list goes on. We bring together a diversity of skills and experiences making YC a place where you can find inspiration every day from the people you work with.

    Some software engineers at YC are former YC founders, and others have worked at startups before or are interested in starting one of their own one day. All of our current engineers are senior, but we’d gladly hire an engineer early in their career that’s eager to learn and develop their technical and product skills.

  • Cross-Department Collaboration

    Engineers at YC work directly with founders and YC partners, as well as our legal, finance, outreach, and operations teams.

    Our goal is simple: scale YC and continuously get better at funding excellent founders and big ideas. It’s a job that is never finished, and the next software hire will do the same work that we all do. You can expect to sit with the engineering team in our open office in San Francisco, working directly with founders and YC staff.

    Every Tuesday and Thursday, all of YC’s partners work with the founders at our Mountain View office doing “Group Office Hours”. Office hours allow founders to meet with partners and talk through problems they’re having. On these evenings, we have dinner and a talk from one of our successful YC founders (think Airbnb, Segment, and PlanGrid founders). Members of the software team are encouraged to get to know the founders, have dinner with them, attend the talks, and occasionally sit in on office hours. As a YC engineer, you also have the opportunity to participate in YC’s interview process (where companies fly in from all over the world to meet with YC partners and potentially join the batch). At the end of each batch, when we have demo day, YC’s software team manages the software and attends the event with the rest of the organization. It’s an exciting and unusual job! Tell us if you think so too.


  • Start-to-Finish Ownership
  • Customer Comes First
  • Ideal for Parents
  • Flat Organization
  • Creative + Innovative
  • Impressive Team Members
  • Cross-Department Collaboration

Company Properties

  • B2B
  • Technical Founder(s)

Team Members

  • 4 Full-Stack Engineers
  • 1 Systems Engineer

Vacation Policy

Our vacation policy is flexible and people at YC really do go on vacation. Take as much vacation as you need.

Tech Stack

The YC internal software is mostly written in Ruby on Rails and React. We’re hosted on AWS and PostgreSQL. Some experience developing web apps would be helpful, but we don't care if you've used Rails before.

Note: Hacker News is written in Lisp, but Hacker News is run by a separate team. While we don't use Lisp anymore in our internal software, we retain the original motivation for it, and welcome Lisp hackers to join us.

Interview Process

Talk with someone on the team for an introductory call. We’ll ask about your background and interests and why you’d like to work at YC. A phone screen with a technical question. Usually this is a coding question either over the phone or in the office if you’re local. A full day on-site. We’ll do things like walk through some code, possibly do some debugging, talk through how you’d approach projects we’re working on. You’ll meet with engineers on the team and a few partners.