Get an API keyGet an API keyThe 5 YC S13 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 |  Professional website design and publishing platform. | 1,847 | +9% | +16% | 46 | $335M | Undisclosed round$400K, Apr 2025 |
| 2 |  Lob is the only automation platform that transforms direct mail into… | 440 | +8% | +14% | 3 | $82.3M | Series C$50M, Feb 2021 |
| 3 |  Improving education for every student. | 412 | +5% | +10% | 9 | $92.7M | Series C$60M, Sep 2021 |
| 4 |  Financial Services for Financial Caregivers. | 108 | +4% | +8% | 4 | $68.3M | Series B$35M, Jul 2020 |
| 5 |  Restaurant delivery. | 84,144 | +3% | +8% | 129 | $5.2B | Post-IPO debt$2.8B, Oct 2026 |
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
52 companies were in Y Combinator's Summer 2013 batch (S13); 10 are active.
6 companies posted roles in the last 60 days, led by DoorDash (129 roles), Webflow (46 roles) and Panorama Education (9 roles). 3 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): Webflow (+9%), Lob (+8%) and Panorama Education (+5%).
No reported rounds after their YC batch in the last 12 months.