Get an API keyGet an API keyThe 4 YC S11 companies whose team grew the most in the last 6 months (active companies with 10+ people).
Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.
| # | Company | Team | 6 mo | 12 mo | Open roles | Total raised | Last round |
|---|---|---|---|---|---|---|---|
| 1 |  Data products for sales, marketing, finance, recruiting, and more. | 100 | +30% | +117% | YC | $2M | Debt$250K, Feb 2016 |
| 2 |  The Leader in Digital Trust & Safety | 283 | +6% | −12% | 4 | $157M | Secondary$50M, Feb 2022 |
| 3 |  Streak transforms Gmail into a powerful CRM | 40 | +5% | +5% | YC | $1.9M | Seed$1.9M, Oct 2012 |
| 4 |  Change the world to value skills over pedigree | 2,231 | +4% | +14% | 3 | $103M | Series D$60M, Mar 2022 |
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
60 companies were in Y Combinator's Summer 2011 batch (S11); 12 are active.
6 companies posted roles in the last 60 days, led by Apollo (8 roles), OneSignal (8 roles) and Sift (4 roles). 7 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): MixRank (+30%), Sift (+6%) and Streak (+5%).
No reported rounds after their YC batch in the last 12 months.