CrustdataGet an API key

YC companies founded by ex-Twitter people

38 Y Combinator companies with a founder who worked at Twitter before.

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

Hiring the mostlast 60 days
4 roles
BenchlingS12
  1. 2Observe.AI3
  2. 3HealthSherpa2
See all 4
Fastest growingteam, 6 months
+53%
PierreW23
  1. 2Garage+46%
  2. 3JustAI+32%
See all 11
Shrinkingteam, 12 months
−15%
Observe.AIW18
  1. 2AmpUp−15%
See all 2
Raised the mostlast 12 months
$22M
VoriW20
  1. 2JustAI$18.7M
  2. 3Garage$17.8M
See all 3
Companies
38
Active
24
Hiring, last 60 days
4
Open roles, 60 days
11
People on these teams
2,341
Showing 38 of 38 companies
CompanyBatchTeam6 mo12 moOpen rolesTotal raisedLast round
Unlocking the power of biotech with modern software for modern science
S12813+3%+3%4$412MSeries F$100M, Nov 2021
Contact center AI platform.
W18358+6%−15%3$214MSeries C$125M, Apr 2022
Private sector Healthcare.gov.
S12255+2%+3%2$6.6MUndisclosed round$6.6M, Feb 2017
Marketplace for America's most essential assets
W24230+46%+150%2$22.8MSeries B$17.8M, Sep 2026
Connecting the world by simulating it
W22107+1%+3%YC
We make EV charging as simple and reliable as LED lights
W1953−2%−15%0$17MSeries A$15M, Sep 2024
Vori is a modern operating system for supermarkets
W2048−27%+7%YC$32.1MSeries B$22M, May 2026
SDK for scanning and verifying credit cards and photo IDs in mobile…
S19Acquired48+4%+12%0$150KYC investment$150K, Aug 2019
Investment management platform for real estate
W2242+11%+11%0$4.5MSeed (before YC)$3.5M, Nov 2021
Agentic Marketing Platform
W2429+32%+93%YC$20.9MSeries A$18.7M, Jun 2026
Hickory turns your employees into experts.
S15Inactive260%−4%0$3.3MSeries A$3.2M, Jan 2017
Pierre is a new, opinionated, git platform.
W2323+53%+77%0SeedJan 2025
Online University for Tech Professionals
S2123+10%+10%0SeedAug 2021
Emails as quick and easy as text messaging.
W16190%0%YC$3.2MYC investment$120K, Mar 2016
Software to launch and integrate genetics into clinical care
W2218+13%+38%YC$9MSeed$8.5M, Jan 2023
The world's fastest calendar, beautifully designed for remote teams.
S18160%−6%0$6.4MSeed$4.5M, Nov 2023
A marketplace for live, online workshops for professionals
S20Inactive120%+9%0SeedAug 2020
The Enablement Layer for Physical AI
S2410+11%+100%0$750KPre-seed$250K, Feb 2025
AI-powered meeting notes and automations
W247+17%+17%YC$3MSeed$2.5M, Nov 2024
Open-source AI coworker with memory
S246  0$500KYC investment$500K, Sep 2024
AI Sales Assistant to increase playbook adoption and win more deals
S2250%0%YC$5.7MSeed$5.2M, Dec 2022
List on multiple resale marketplaces
S21Inactive50%0%0SeedSep 2021
Helps teams work effectively with AI coding agents.
W244−50%−56%0$500KYC investment$500K, Feb 2024
S20Acquired4−20%−56%0$11.4MUndisclosed round$5M, Oct 2023
Managed GPU-accelerated Spark + SQL at 2x speed and half the cost
X252  0$500KYC investment$500K, Jun 2025
AI to track and analyze public policy
W212  0Pre-seedMar 2021
S19Acquired2  0
On demand veterinary house calls.
W15Inactive2  0$1.1MSeed$365K, Sep 2016
AI Overview Search, as a Service
S23Inactive1  0$500KYC investment$500K, Sep 2023
AI-native operating system for analytics teams
W23Inactive1  0$500KYC investment$500K, Apr 2023
Bandit ML builds machine learning tools for e-commerce companies.
S20Acquired1  0$1.5MPre-seed$1.3M, Sep 2020
Acquired by Brex. Building digital payments infrastructure.
W19Acquired1  0SeedMar 2019
Clear Genetics is scaling delivery of Genomic services
W17Acquired1  0$2.5MUndisclosed round$2.5M, Nov 2019
SaaS calendar and messaging for SMBs
W17Inactive1  0
W10Inactive1  0SeedJan 2010
India's largest crypto investing paltform
W19165  0$22.1MUndisclosed round$12.3M, Aug 2022
See and control what your agents actually do
F26  0
The AI-native radiology practice
S26  0

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-Twitter founded YC companies

How many ex-Twitter founded YC companies are there?

38 Y Combinator companies have a founder who worked at Twitter; 24 are active.

Which ex-Twitter founded YC companies are hiring?

4 companies posted roles in the last 60 days, led by Benchling (4 roles), Observe.AI (3 roles) and HealthSherpa (2 roles). 8 mark themselves as hiring on YC's directory.

Which ex-Twitter founded YC companies are growing fastest?

By team growth over 6 months (10+ people): Pierre (+53%), Garage (+46%) and JustAI (+32%).

Which ex-Twitter founded YC companies raised the most?

Largest latest rounds in the last 12 months, after their YC batch: Vori ($22M), JustAI ($18.7M) and Garage ($17.8M).

Browse YC companies

By batch

Show fewer

By industry

Show fewer

By location

Show fewer

By founders' past employer

Show fewer