CrustdataGet an API key

YC companies founded by ex-Scale AI people

23 Y Combinator companies with a founder who worked at Scale AI before.

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

Hiring the mostlast 60 days
12 roles
SieveW22
  1. 2David AI8
  2. 3Sendblue1
See all 3
Fastest growingteam, 6 months
+83%
NovaflowS25
  1. 2Sieve+52%
  2. 3Sendblue+18%
See all 4
Companies
23
Active
21
Hiring, last 60 days
3
Open roles, 60 days
21
People on these teams
408
Showing 23 of 23 companies
CompanyBatchTeam6 mo12 moOpen rolesTotal raisedLast round
iMessage for Sales
S2365+18%+30%1
AI Applied Research
W2462−2%+5%0$17.5MSeries A$17M, Jun 2025
The multimodal data lab
W2250+52%+178%12$4.1MSeed$4M, Nov 2022
An AI tutor that helps you study
S23160%0%0$2.3MSeed$2.3M, Jan 2025
AI rebuilt coding. We’re rebuilding the phone
S2512−14%+9%YC$500KYC investment$500K, Sep 2025
The AI data analyst for biology labs
S2511+83%+83%YC$500KYC investment$500K, Jul 2025
Manage energy cost & usage with AI for facility & sustainability teams
S2310+11%+11%YC$500KYC investment$500K, Jan 2024
Advancing model capabilities for critical infrastructure
S266  0$500KYC investment$500K, Sep 2026
Make every FDE on your team capable of moving any account forward.
S256  YC$500KYC investment$500K, Sep 2025
AI powered brokerage reducing residential rental commissions in NYC…
S2550%−44%0$500KYC investment$500K, Sep 2025
AEO/GEO for E-Commerce and Retail
W255  YC$500KYC investment$500K, Mar 2025
AI-native credentialing and contracting for healthcare
X264  0
The AI Growth Engine for Industrials
W254  YC
AI lab in San Francisco
W224  0$2.1MPre-seed$2M, Jun 2022
Reason is the AI teammate for work and code.
F262  YC
Turn any website into an MCP for your agents, in minutes
F262  0
Building secure polymorphic apps
W262  0$500KYC investment$500K, Apr 2026
Long-horizon RL environments
S252  YCPre-seedSep 2025
The content engine that wins attention and drives growth.
S242−60% 0
Turn user feedback to product insights
S22Acquired2  0SeedJun 2023
API sandboxes, built for AI agents
S261  0$500KYC investment$500K, Dec 2025
Accelerating data analysis for research
X25Inactive1  0
Data for audio AI
S24134  8$80.5MSeries B$50M, Oct 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 ex-Scale AI founded YC companies

How many ex-Scale AI founded YC companies are there?

23 Y Combinator companies have a founder who worked at Scale AI; 21 are active.

Which ex-Scale AI founded YC companies are hiring?

3 companies posted roles in the last 60 days, led by Sieve (12 roles), David AI (8 roles) and Sendblue (1 roles). 11 mark themselves as hiring on YC's directory.

Which ex-Scale AI founded YC companies are growing fastest?

By team growth over 6 months (10+ people): Novaflow (+83%), Sieve (+52%) and Sendblue (+18%).

Which ex-Scale AI founded YC companies raised the most?

No reported rounds after their YC batch in the last 12 months.

Browse YC companies

By batch

Show fewer

By industry

Show fewer

By location

Show fewer

By founders' past employer

Show fewer