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W21 companies that raised the most in the last 12 months

The 18 YC W21 companies whose latest reported round, after their YC batch and in the last 12 months, was the largest.

Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.

Showing 18 of 18 companies on this list
#CompanyTeam6 mo12 moOpen rolesTotal raisedLast round
1
Seamless mobility to, through, and from space. It starts with 100%…
451+17%+33%4$2.4BSeries E$1B, Sep 2026
2
Telehealth dietitians covered by insurance
4,256  7$213MSeries C$100M, May 2026
3
Get up and running with large language models.
77+38%+64%0$80.1MSeries B$65M, Jul 2026
4
The data layer for physical AI
231+31%+75%3$110MSeries C$60M, Feb 2026
5
Protecting the grid today, preparing the grid for tomorrow
221+18%+51%1$97.2MSeries B$55M, Nov 2025
6
Voice AI for developers.
150+50%+114%4$70.6MSeries B$50M, May 2026
7
Modernizing commercial insurance
107+11%+43%17$61.6MSeries B$42M, Mar 2026
8
all-in-one operating system (OS) for telcos
121+34%+51%8$66.3MSeries B$40M, Mar 2026
9
Internet for the urban developing world.
382+18%+41%0$75.6MSeries B$40M, Mar 2026
10
A digital wallet for the Middle East & North Africa
324+15%+45%5$30.5MSeries A$22M, May 2026
11
AI Agents for Oncology EHRs
98+48%+72%3$37.1MSeries B$22M, May 2026
12
Shift FinOps Left: Proactively Find & Fix Cloud Cost Issues
29 +16%YC$21.9MSeries A$18.8M, Nov 2025
13
Recover from any outage in 10 minutes or less.
51+46%+65%0$26.2MSeries A$15.9M, Jun 2026
14
AI-powered Compliance Platform for PCI 4, CCPA, HIPAA, CIPA, 50+ laws
51−4%+38%0$25.8MSeries A$14M, Nov 2025
15
User research on autopilot.
59−6%−11%4$15.5MSeries A$13M, Nov 2025
16
Tech-enabled fulfillment provider in the Middle East & Africa
190  0$15.9MSeries A$12.6M, Feb 2026
17
Source better parts by partnering directly with vetted manufacturers
122+8%+30%1$16.1MSeries A$12.1M, Nov 2025
18
The AI Underwriting OS for Commercial, Specialty & E&S insurance
167+7%+37%0$7.7MSeries A$7M, Nov 2025

How this works

1. The roster

Every launched company in YC's public directory, with its batch, status, industry and location. New companies show up the week YC lists them.

2. The numbers

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.

3. The lists

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.

Built with Crustdata. Get your own API key and build your own.

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.

  • Company search for team size, growth and funding
  • Job search with a count by company, for who is hiring and for what
  • A watch that re-runs the search weekly and sends only what changed
# 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

Questions about YC W21 companies

How many YC W21 companies are there?

334 companies were in Y Combinator's Winter 2021 batch (W21); 226 are active.

Which YC W21 companies are hiring?

46 companies posted roles in the last 60 days, led by REGENT (30 roles), Shepherd (17 roles) and Codingal (9 roles). 77 mark themselves as hiring on YC's directory.

Which YC W21 companies are growing fastest?

By team growth over 6 months (10+ people): OpenCode (+200%), Venu AI (+58%) and Vapi (+50%).

Which YC W21 companies raised the most?

Largest latest rounds in the last 12 months, after their YC batch: Stoke Space ($1B), Nourish ($100M) and Ollama ($65M).

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