The 31 YC X25 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.
| # | Company | Team | 6 mo | 12 mo | Open roles | Total raised | Last round |
|---|---|---|---|---|---|---|---|
| 1 | Industrial data layer for physical RSI | 56 | +331% | 0 | $7.6M | Seed$6M, Jun 2026 | |
| 2 | Autonomous Company Infrastructure | 15 | +150% | +200% | 3 | $28.5M | Series A$28.5M, Aug 2026 |
| 3 | Intelligence Infrastructure on People and Entities | 13 | +117% | +160% | YC | $500K | YC investment$500K, Apr 2025 |
| 4 | A personal EA in your iMessage | 10 | +100% | +43% | 1 | $2M | Seed$2M, Jun 2025 |
| 5 | Build autonomous AI agents for enterprise systems | 50 | +92% | +355% | 4 | ||
| 6 | The Agent-Native Computer | 13 | +86% | +117% | YC | ||
| 7 | Vertical AI agents running B2B outbound on autopilot, with human SDRs | 140 | +77% | +724% | 0 | $6.2M | Seed$6.2M, Sep 2025 |
| 8 | Autonomous security testing for web apps, APIs, cloud, and AI systems | 21 | +75% | +200% | YC | $17.2M | Series A$13M, Jul 2026 |
| 9 | Agentic AI platform for Pharma GTM teams | 39 | +63% | +144% | YC | $5M | Seed$5M, Nov 2025 |
| 10 | AI Revenue Platform for Post-Acute Care | 13 | +63% | +160% | 3 | $4.9M | Seed$4.4M, Jan 2026 |
| 11 | Open-source agents to build predictive ML models from a prompt | 11 | +57% | +57% | YC | $2.1M | Seed$2.1M, Aug 2025 |
| 12 | Streamlining Data Capture to Report Creation for Heavy Industries | 11 | +57% | +83% | 0 | $500K | YC investment$500K, Jun 2025 |
| 13 | quantum-accelerated AI servers | 48 | +50% | +118% | 8 | $139M | Series A$105M, Mar 2026 |
| 14 | 24/7 Global Stock Exchange | 12 | +50% | +50% | YC | $10M | Seed$9.5M, Mar 2026 |
| 15 | All-In-One AI Growth Partner. Built for Trades. | 13 | +44% | +44% | 0 | $7.5M | Seed$7M, Nov 2025 |
| 16 | Specialized AI for Every Job | 14 | +40% | 0 | Undisclosed roundJan 2026 | ||
| 17 | AI-Native IP Enforcement | 18 | +38% | +100% | YC | $500K | YC investment$500K, Mar 2025 |
| 18 | Your AI Chief of Staff | 11 | +38% | +83% | YC | SeedJul 2025 | |
| 19 | The agentic operating system for modern system integrators. | 48 | +37% | +167% | 3 | $20.5M | Series A$20M, Apr 2026 |
| 20 | Test, monitor, and improve your voice and chat AI agents | 16 | +33% | +129% | YC | $4M | Seed$4M, Aug 2025 |
| 21 | Software to monitor, control, and optimize data centers. | 13 | +30% | +63% | YC | $5.1M | Seed$5.1M, Dec 2025 |
| 22 | AI Driven EPC - Weld Fabrication Contractor | 18 | +29% | +157% | 1 | SeedJun 2025 | |
| 23 | Secure internal apps. Built by AI in seconds. Powered by your data. | 14 | +27% | +56% | 0 | $10.5M | Seed$10M, Dec 2025 |
| 24 | Function Health for Europe | 44 | +26% | +100% | 3 | $28.5M | Series A$20M, May 2026 |
| 25 | We build software factories for engineering teams | 10 | +25% | +11% | YC | SeedJun 2025 | |
| 26 | The agentic CRM for blue-collar services | 11 | +22% | +22% | 0 | Pre-seedJun 2025 | |
| 27 | Voice data for AI | 18 | +13% | +260% | YC | $3.5M | Seed$3M, Nov 2025 |
| 28 | AI native financial institution | 10 | +11% | +11% | 0 | SeedApr 2025 | |
| 29 | Industrial Robots that Learn and Operate Like Humans | 13 | +8% | +8% | YC | $500K | YC investment$500K, Jun 2025 |
| 30 | The AI Operator for Financial Services | 13 | +8% | −7% | 2 | $9.4M | Non-equity support$1M, Oct 2025 |
| 31 | Vertical AI for highly-regulated manufacturing | 14 | +8% | +56% | 1 | $500K | YC investment$500K, 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
144 companies were in Y Combinator's Spring 2025 batch (X25); 136 are active.
11 companies posted roles in the last 60 days, led by Sygaldry Technologies (8 roles), Sim (4 roles) and Lucis (3 roles). 57 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): Linewise (+331%), Naïve (+150%) and Sixtyfour (+117%).
Largest latest rounds in the last 12 months, after their YC batch: Sygaldry Technologies ($105M), Naïve ($28.5M) and Foundation Industries ($25M).