Get an API keyGet an API keyThe 11 YC S14 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 |  Emission free, always on power from advanced fission power plants. | 418 | +28% | +75% | 3 | $1.4B | Post-IPO equity$1B, Sep 2026 |
| 2 |  Building the world's first fusion power plant | 594 | +11% | +34% | 49 | $1.5B | Series G$500M, Jun 2026 |
| 3 |  Marketplace to get stuff from overseas | 31 | +7% | +3% | 0 | $120K | Seed$120K, Nov 2019 |
| 4 |  Nanotechnology-enabled coatings for automotive and defence sectors | 33 | +6% | +32% | 0 | $7.9M | Grant$4.3M, Jan 2026 |
| 5 |  Customer communications hub for building strong relationships | 579 | +6% | +13% | 4 | $204M | Series D$65M, Jun 2022 |
| 6 |  Quantum coherent supercomputing. | 204 | +6% | +19% | 0 | $883M | Grant$100M, May 2026 |
| 7 |  Providing Amazon level logistics to e-commerce businesses. | 1,730 | +6% | +14% | 35 | $331M | Series E$200M, Jun 2021 |
| 8 |  The AI Command Center for outbound and ABM | 108 | +5% | +2% | 1 | $22.4M | Series A$20M, Oct 2021 |
| 9 |  Crypto-currency trading platform. | 95 | +3% | +3% | 0 | $23.1M | Series B$23M, Mar 2025 |
| 10 |  People infrastructure for the future of work | 1,846 | +3% | +14% | 28 | $740M | Undisclosed round$61.1M, May 2025 |
| 11 |  Marketing automation for event promoters (email, sms, ads, CRM) | 78 | +3% | +11% | YC | $27.1M | Secondary$27M, 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
78 companies were in Y Combinator's Summer 2014 batch (S14); 21 are active.
8 companies posted roles in the last 60 days, led by Helion Energy (49 roles), ShipBob (35 roles) and Checkr (28 roles). 5 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): Oklo (+28%), Helion Energy (+11%) and Backpack (+7%).
Largest latest rounds in the last 12 months, after their YC batch: Helion Energy ($500M).