Get an API keyGet an API key10 Y Combinator companies with a founder who worked at Box before.
Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.
NumeralW23
Medplum1NumeralW23Medplum+14%
Vector+3%NumeralW23Vector$10M
Risely AI$3.6M| Company | Batch | Team | 6 mo | 12 mo | Open roles | Total raised | Last round |
|---|---|---|---|---|---|---|---|
The AI-native sales tax solution. | W23 | 173 | +25% | +63% | 2 | $158M | Series C$100M, Sep 2026 |
Advertising for the new internet | W23 | 93 | +3% | +19% | YC | $10M | Series A$10M, May 2026 |
 Dashboards and actionable insights for high-performing engineering… | W20Acquired | 61 | +2% | +5% | 0 | $6.6M | Seed$4.4M, Feb 2022 |
 The All-in-One Learning Platform | S16Acquired | 38 | −27% | −37% | 0 | $67.2M | Series C$40M, Mar 2022 |
API first electronic health record (EHR) that is open source | S22 | 24 | +14% | +71% | 1 | GrantMar 2023 | |
AI agents that automate administrative work across college campuses. | S25 | 9 | +50% | +29% | 0 | $4.1M | Seed$3.6M, May 2026 |
 Clinical skincare tested on diverse skin, now available in Sephora. | W21 | 9 | 0 | $3.1M | Seed$3M, Jul 2023 | ||
 tEQuitable's mission is to create work culture that works for everyone | W18 | 3 | 0 | $2M | Angel$1.6M, Jun 2018 | ||
 Acquired by Brex. Building digital payments infrastructure. | W19Acquired | 1 | 0 | SeedMar 2019 | |||
 Last mile logistics for delivery & service teams. We bring real-time… | S16Acquired | 1 | 0 | SeedMar 2017 |
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
10 Y Combinator companies have a founder who worked at Box; 6 are active.
2 companies posted roles in the last 60 days, led by Numeral (2 roles) and Medplum (1 roles). 3 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): Numeral (+25%), Medplum (+14%) and Vector (+3%).
Largest latest rounds in the last 12 months, after their YC batch: Numeral ($100M), Vector ($10M) and Risely AI ($3.6M).