Get an API keyGet an API keyAll 26 companies in Y Combinator's Summer 2009 batch, with team size, growth, open roles and funding.
Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.
StripeS09
Mixpanel26MixpanelS09Stripe+8%| Company | Team | 6 mo | 12 mo | Open roles | Total raised | Last round |
|---|---|---|---|---|---|---|
Economic infrastructure for the internet. | 16,694 | +8% | +21% | 659 | $10B | Secondary$694M, Mar 2026 |
Mixpanel is event analytics for builders that need answers. | 771 | +18% | +43% | 26 | $277M | Series C$200M, Nov 2021 |
 Mobile marketplace for trading used goods. | 19 | 0% | 0% | 0 | $26.2M | Token sale$15M, Jan 2018 |
 The open source database for the realtime web. | 19 | 0% | 0% | 0 | $12.2M | Series A$8M, Dec 2013 |
 Olark gives you an AI agent that works your marketing funnel 24/7 | 16 | −11% | −6% | 0 | SeedJun 2009 | |
 Apartment rental marketplace | 13 | 0% | +8% | YC | $25K | Seed$25K, Apr 2014 |
 The best way to buy a new car. | 4 | 0 | ||||
Product recommendations. | 2 | 0 | $15K | YC investment$15K, Jun 2009 | ||
HighlightCam edits video, automatically! | ||||||
 | 0 | $7M | Series A$6M, Mar 2011 | |||
 Bump, Flock, Photoroll (unreleased) => Google Photos | ||||||
 Payments for platform businesses. | ||||||
 Lockitron makes electronic locks you can control locally from your… | 0 | Undisclosed roundApr 2013 | ||||
 Online marketplace for equipment rental | ||||||
 FanChatter aggregates, amplifies and empowers fan content on every… | 0 | $20K | YC investment$20K, Jun 2009 | |||
 We let you know where to go and what to get once you get there.… | 0 | $20K | Undisclosed round$20K, Dec 2009 | |||
Online IDE. We joined Microsoft in 2014. | ||||||
Lingt provided a web-based platform for learning languages leveraging… | ||||||
Every launched company in YC's public directory, with its batch, status, industry and location. New companies show up the week YC lists them.
Each company is matched to Crustdata by its website. Crustdata adds team size and its change over 6 and 12 months, open roles from job postings, reported funding, and founders' past employers.
Hiring the most counts distinct roles posted in the last 60 days. Growth needs 10+ people today, shrinking 20+ a year ago, so tiny teams do not top the lists. Rebuilt every week.
The numbers on this page come from three Crustdata API calls. Crustdata tags 5,000+ companies with Y Combinator as an investor; swap the filter for any investor, industry or headcount range and track your own list, with founders' work emails one call away.
# 1. every company with Y Combinator as an investor curl https://api.crustdata.com/company/search \ -H "authorization: Bearer $CRUSTDATA_API_KEY" \ -H "x-api-version: 2025-11-01" \ -d '{ "filters": { "field": "funding.investors", "type": "in", "value": ["Y Combinator"] }, "fields": ["basic_info.name", "headcount.total", "headcount.growth_percent", "funding.total_investment_usd"], "limit": 100 }' # 2. open listings per company, last 60 days (limit 0 = counts only) curl https://api.crustdata.com/job/search \ -H "authorization: Bearer $CRUSTDATA_API_KEY" \ -H "x-api-version: 2025-11-01" \ -d '{ "filters": { "op": "and", "conditions": [ { "field": "company.basic_info.company_id", "type": "in", "value": [...] }, { "field": "metadata.date_added", "type": "=>", "value": "2026-08-24" } ]}, "limit": 0, "aggregations": [{ "type": "group_by", "field": "company.basic_info.company_id", "agg": "count" }] }' # 3. the same company filter as a weekly watch: POST /watch/company/search
26 companies were in Y Combinator's Summer 2009 batch (S09); 7 are active.
2 companies posted roles in the last 60 days, led by Stripe (659 roles) and Mixpanel (26 roles). 2 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): Mixpanel (+18%) and Stripe (+8%).
No reported rounds after their YC batch in the last 12 months.