Get an API keyGet an API key15 Y Combinator companies with a founder who worked at Datadog before.
Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.
TolmoX26
Metal1
Plena HealthX26
Nowadays+58%Tolmo+44%TolmoX26| Company | Batch | Team | 6 mo | 12 mo | Open roles | Total raised | Last round |
|---|---|---|---|---|---|---|---|
 Plaid for supply chain logistics | W23 | 24 | +14% | +14% | 0 | $3.1M | Seed$2.6M, Nov 2023 |
AI-native platform for corporate meetings and events | S23 | 19 | +58% | +46% | YC | $2.5M | Seed$2M, Dec 2024 |
Tolmo is the AI security platform that secures every layer of cloud… | X26 | 13 | +44% | 5 | $22M | Seed$22M, Jun 2026 | |
Plena is the AI operating system for specialty medical practices | X26 | 10 | +67% | +67% | YC | $500K | YC investment$500K, Jun 2026 |
 AI sales roleplay built from your real deals | S25 | 6 | +20% | 0 | $500K | YC investment$500K, Jul 2025 | |
 Expedia for ordering blank apparel | W24Inactive | 4 | −20% | 0 | $500K | YC investment$500K, Apr 2024 | |
 Test agents in realistic worlds built from production usage | F26 | 3 | 0 | ||||
 Make software self-healing | X26 | 3 | 0 | $500K | YC investment$500K, Jun 2026 | ||
 AI-native operating system for vehicle fleet management | X25 | 3 | 0 | $500K | YC investment$500K, Jul 2025 | ||
 Conversational AI surveys with intelligent follow-up questions | W24 | 3 | 0 | ||||
 Independent AI evaluations lab | S25 | 2 | 0 | ||||
 Close your outdated dependency attack vector | S23Acquired | 1 | 0 | $3.7M | Seed$3.2M, Dec 2023 | ||
 Run compute-intensive apps in a browser | W22Acquired | 1 | 0 | ||||
 Observability for Data Engineering Teams | S21Inactive | 1 | 0 | $1.3M | Pre-seed$1.3M, Sep 2021 | ||
The AI context platform for private capital. Everything your firm… | W23 | 528 | 1 | $7.5M | Seed$5M, Sep 2025 |
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
15 Y Combinator companies have a founder who worked at Datadog; 11 are active.
2 companies posted roles in the last 60 days, led by Tolmo (5 roles) and Metal (1 roles). 3 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): Plena Health (+67%), Nowadays (+58%) and Tolmo (+44%).
Largest latest rounds in the last 12 months, after their YC batch: Tolmo ($22M).