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Fastest growing S19 companies

The 38 YC S19 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.

Showing 38 of 38 companies on this list
#CompanyTeam6 mo12 moOpen rolesTotal raisedLast round
1
Human and AI design review for hardware
281+31%+71%2$134MDebt$728K, Mar 2026
2
Learn how to build a scalable growth engine
13+30%+18%0SeedAug 2019
3
A better data science notebook.
22+29%−31%YC$23.8MSeries A$20M, Jan 2022
4
Point of sale financing for Latin America's middle class.
27+29%+17%0$150KYC investment$150K, Aug 2019
5
Payment Platform for LatAm Micro and Small Businesses
116+23%+26%YC$88.5MDebt$42.3M, Feb 2026
6
Construction & industrial logistics platform.
318+21%+42%1$48.1MSeries B$42M, Jul 2024
7
Modern online payments for the Philippines
143+20%+17%0$45.7MSeries B$31M, Feb 2022
8
Modern medical billing
23+15%+21%YC$150KYC investment$150K, Aug 2019
9
The leading Composable CDP and AI Decisioning platform
658+14%+51%52$332MSeries D$150M, Apr 2026
10
Making diverse, high-quality data easily available to anyone, anywhere
1,580+14%+72%19$33.5MSeries A$32.3M, Jul 2023
11
TRM is building a safer world for billions of people.
481+14%+36%67$220MSeries C$70M, Sep 2026
12
Modern ecommerce for petite women
190+14%+23%3$2.9MSeed$2.9M, Sep 2021
13
Predictive Explorer and Driller for Critical Metal Deposits
44+13%+33%0$34MSeries B$20M, Jan 2025
14
The Fastest Scientific Computing Platform on the Planet
10+11% YC$150KSeries A$150K, Mar 2022
15
A zero inventory, zero returns factory-to-consumer apparel company
53+10%+18%YC$150KYC investment$150K, Mar 2021
16
Building the safety net of the future
320+10%+20%3$19.5MUndisclosed round$500K, Jun 2024
17
The LatAm tech-enabled real estate broker to buy and sell houses.
252+9%+7%0$13.4MSeries A$10M, Aug 2022
18
We build robots for dull, dirty, and dangerous jobs.
90+8%+8%1$36.4MSeries B$20M, Mar 2026
19
We help companies scale marketing campaigns through WhatsApp
66+8%+2%0$15MSeries A$15M, Jul 2022
20
Building a better way to meet online.
82+8%−13%2$76MSeries B$50M, Nov 2021
21
Household needs, from bread to everything.
2,667+7%+21%0$89MSeries C$50M, Feb 2026
22
Building the NASDAQ for Real Estate.
19+6%+6%0$5MUndisclosed round$3M, Feb 2022
23
AI platform accelerating therapies for rare & inflammatory diseases.
20+5%+18%0$22.5MUndisclosed round$5.5M, Dec 2025
24
Discovering the true signals of disease to power life-changing drugs.
21+5%+17%0Undisclosed roundMay 2021
25
Online pets supplies for Latin America with over 4000 products & 20…
393+4%+2%0$65MSecondary$48M, May 2023
26
Canix makes it easy to get and stay compliant as a cannabis business.
28+4%−3%0$14MSeries A$10M, Jun 2022
27
Workforce platform to recruit, license, credential & manage clinicians
116+4%+6%17$3MUndisclosed round$3M, Nov 2022
28
Financial connectivity API for consumer liabilities
89+3%+22%8$60.5MSeries B$42M, Jan 2025
29
Helping create a smaller, fairer, safer justice system
120+3%+18%YC$200KGrant$100K, Jan 2025
30
LineLeap gets customers to the fun, faster.
92+3%−11%1$30.8MUndisclosed round$10M, Nov 2025
31
All-In-One Creator Store
31+3%+7%YC$3.5MSeed$200K, May 2022
32
Our operations software makes it easier to run--and grow--your cafe
221+3%+11%21$352MUndisclosed round$96M, Aug 2026
33
Your global dollar account powered by stablecoins
64+3% 0
34
AI recruiter for India's massive blue-collar workforce
362+3%+1%1$18MUndisclosed round$10M, Jul 2025
35
In-Person, Hybrid and Virtual Event Management Software
102+3%+2%YC$4MSeed$1M, Nov 2021
36
Modern payroll for modern work
40+3%+5%0$30.4MSeries B$15M, Oct 2024
37
Building AI therapeutics for physical health conditions like IBS.
48+2%+4%0$19.7MSeries A$12M, Mar 2023
38
UpEquity gives homebuyers more certainty and power.
62+2%+3%1$277MDebt$200M, Jun 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 S19 companies

How many YC S19 companies are there?

174 companies were in Y Combinator's Summer 2019 batch (S19); 100 are active.

Which YC S19 companies are hiring?

19 companies posted roles in the last 60 days, led by TRM Labs (67 roles), Lokal (63 roles) and Hightouch (52 roles). 30 mark themselves as hiring on YC's directory.

Which YC S19 companies are growing fastest?

By team growth over 6 months (10+ people): CoLab (+31%), Demand Curve (+30%) and Deepnote (+29%).

Which YC S19 companies raised the most?

Largest latest rounds in the last 12 months, after their YC batch: Hightouch ($150M), Odeko ($96M) and TRM Labs ($70M).

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