The 100 YC S21 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 | AI engineering capacity. Made simple. ⚡️ | 10 | +100% | YC | Pre-seedAug 2021 | ||
| 2 | The AI-Native Turnkey Alternative Investment Platform (TAIP) | 29 | +93% | +142% | YC | $18.9M | Series A$15M, Sep 2026 |
| 3 | AI-enabled financial automation and intelligence for CPG Brands | 121 | +89% | +163% | 22 | $75M | Series B$55M, Sep 2026 |
| 4 | Accelerate software development with WarpBuild's 10x faster CI infra. | 12 | +71% | +71% | 1 | $1.5M | Pre-seed$1.5M, Aug 2021 |
| 5 | AI native ATS + CRM for executive search firms | 10 | +67% | +100% | YC | $2.1M | Seed$2.1M, Jan 2025 |
| 6 | AI Business Analysts to gather requirements and optimize processes | 19 | +58% | +73% | YC | $4.4M | Non-equity support$4.3M, Mar 2026 |
| 7 | The global financial platform for affluent consumers in the Americas. | 277 | +49% | +147% | 24 | ||
| 8 | Web search rebuilt for LLMs | 243 | +46% | +117% | 28 | $357M | Series C$250M, May 2026 |
| 9 | Plaid for Brazil: we allow developers to access users' financial data | 48 | +33% | +71% | 0 | $5.2M | Series A$3.5M, Aug 2026 |
| 10 | Salary on-demand platform for Latin America | 20 | +33% | +67% | 0 | $125K | YC investment$125K, Aug 2021 |
| 11 | Banking, corporate cards, stablecoin payments, available globally. | 98 | +31% | +63% | 3 | $160M | Series C$100M, Apr 2026 |
| 12 | We're building fully automated labs for protein engineering | 40 | +29% | +43% | YC | $50.9M | Series A$40M, Aug 2026 |
| 13 | Speech and accent coaching app for non-native English speakers | 27 | +29% | +69% | 2 | $27.1M | Series A$21M, Dec 2025 |
| 14 | AI-Powered ERP, MES, and Test Software for Complex Operations | 42 | +27% | +45% | YC | $18.8M | Series A$15M, Jun 2022 |
| 15 | Orbital logistics: Unleashing space industry, from Earth to asteroids | 34 | +26% | +3% | YC | $9.5M | Undisclosed round$2.5M, Sep 2025 |
| 16 | AI-native on-call and incident response carefully crafted to help… | 93 | +22% | +27% | 1 | $15.2M | Series A$12M, Aug 2023 |
| 17 | Easiest way for companies to process data requests from governments | 99 | +22% | +62% | 5 | $41.2M | Series A$21.2M, Sep 2025 |
| 18 | Software that helps employees pick their employee benefits. | 34 | +21% | +36% | 0 | $11.1M | Series A$7.8M, Jul 2022 |
| 19 | Unlocking the next generation of mRNA medicines | 35 | +21% | +35% | 0 | $70.9M | Series A$20M, Oct 2026 |
| 20 | Turning space into a transportation layer for Earth | 131 | +20% | +30% | 3 | $54.3M | Series A$44M, Nov 2024 |
| 21 | TURN STATIC DOCS INTO INSTANT ANSWERS | 18 | +20% | +13% | 0 | $3M | Seed$2M, Feb 2022 |
| 22 | Developer friendly drop in payouts infrastructure | 18 | +20% | +50% | YC | $14.8M | Series A$8.9M, Feb 2026 |
| 23 | Autonomous medical care | 40 | +18% | +60% | 15 | $7.6M | Seed$5.6M, Jan 2026 |
| 24 | One source of truth for financial data. | 107 | +18% | +45% | 1 | $46.1M | Series B$29.2M, Sep 2025 |
| 25 | One stop investment solution for retail investors in Latam | 63 | +17% | +17% | 1 | $7.9M | Undisclosed round$3M, Jun 2025 |
| 26 | Autonomous Stratospheric UAVs | 21 | +17% | +17% | YC | $450K | Seed$450K, Jan 2023 |
| 27 | Native user-facing SaaS integrations for your customers | 22 | +16% | +5% | 0 | $5.6M | Seed$4M, Oct 2024 |
| 28 | Flexible Business Apps for Modern Teams | 22 | +16% | +22% | YC | $5.4M | Seed$4M, Aug 2024 |
| 29 | Patent-pending enzymes to break down common dietary triggers | 15 | +15% | +36% | 0 | $1.6M | Seed$1.5M, Oct 2021 |
| 30 | Help ML teams label the right data | 38 | +15% | +15% | YC | $3.1M | Seed$3M, May 2022 |
| 31 | We make injections as easy as pushing a button! | 31 | +15% | +29% | YC | ||
| 32 | Robots that build solar farms | 31 | +15% | +24% | 15 | $17M | Undisclosed round$17M, Aug 2024 |
| 33 | Empowering local businesses to sell online. | 47 | +15% | +24% | 0 | $4.2M | Seed$4.1M, Feb 2022 |
| 34 | AI Copilot for insights & strategy | 24 | +14% | +33% | YC | ||
| 35 | Virtual Co-working Community | 17 | +13% | +13% | 0 | $5.1M | Seed$5M, Jul 2022 |
| 36 | Learning app for school students in Southeast Asia | 157 | +13% | +15% | 0 | $1.7M | Seed$1.6M, Jan 2022 |
| 37 | Payments and scheduling for services professionals in LATAM | 186 | +13% | +28% | 0 | $1.6M | Seed$1.5M, Nov 2021 |
| 38 | AirBnB for Small Warehouses | 71 | +13% | +42% | 0 | $2.8M | Undisclosed round$2M, Sep 2025 |
| 39 | One API to get clean data from any website for your AI agents at scale | 160 | +13% | +27% | 0 | $2M | Seed$2M, Dec 2021 |
| 40 | Online Training for Healthcare Jobs | 449 | +12% | +33% | 36 | $111M | Series C$55M, Jun 2026 |
| 41 | Flexible On-Demand Storage Space for Household, SMEs & Travellers. | 85 | +12% | +20% | 0 | $630K | Seed$505K, Dec 2021 |
| 42 | We visually monitor space objects for governments and defense | 125 | +12% | +21% | 0 | $38.4M | Series B$26.4M, Sep 2026 |
| 43 | AI CAD Software for Civil Engineering | 40 | +11% | +21% | 8 | $16.8M | Seed$14.4M, Jul 2024 |
| 44 | Make all team work visible, people and AI agents | 10 | +11% | 0 | Pre-seedAug 2021 | ||
| 45 | The UAE’s leading small business payments platform | 62 | +11% | +24% | 0 | $3.4M | Seed$3.4M, Nov 2021 |
| 46 | Amazon Level Logistics for eCommerce Companies in MENA. | 126 | +11% | +8% | 0 | $2.6M | Pre-seed$2.4M, Oct 2021 |
| 47 | The everything app for LATAM | 1,132 | +10% | +27% | 1 | $71M | Series A$47M, Jun 2022 |
| 48 | Account Receivables Platform for Latin American Enterprises | 367 | +10% | +27% | 14 | $66.5M | Series A$48M, Apr 2025 |
| 49 | Saving OPS from SLOPS. Jestor builds internal systems that last. | 23 | +10% | +44% | 0 | $345K | YC investment$345K, Aug 2021 |
| 50 | Online University for Tech Professionals | 23 | +10% | +10% | 0 | SeedAug 2021 | |
| 51 | We help Accountants automate work and serve their customers online | 83 | +9% | +9% | 1 | $2.7M | Seed$2.2M, Mar 2022 |
| 52 | Demo operations for the AI era | 36 | +9% | +50% | YC | $2.1M | Seed$2.1M, Apr 2023 |
| 53 | Reinventing respiration monitoring | 12 | +9% | +9% | 0 | $164K | Equity crowdfunding$39K, Mar 2023 |
| 54 | Onebrief makes military headquarters run seamlessly | 391 | +9% | +55% | 7 | $311M | Grant$114K, Jul 2026 |
| 55 | Organic and gourmet high-protein meals, designed for longevity. | 91 | +8% | +7% | 0 | $16.1M | Seed$14M, May 2022 |
| 56 | Private workspace for founders, investors, and advisors to collaborate | 26 | +8% | +4% | 0 | $125K | YC investment$125K, Aug 2021 |
| 57 | We make cancer care at home possible. | 67 | +8% | +24% | 0 | $60.6M | Series A$21M, Jan 2026 |
| 58 | CRISPR powered Diagnostics with results in minutes. | 27 | +8% | +8% | 0 | $65M | Series A$25M, Sep 2025 |
| 59 | Automated communication between hospitals and patients in Latam | 41 | +8% | 0 | $125K | YC investment$125K, Aug 2021 | |
| 60 | Automated e2e screenshot testing without writing or maintaining tests | 28 | +8% | +87% | YC | $19.1M | Series A$15M, Jul 2026 |
| 61 | Truss is a banking and payments network for blue-collar trades. | 14 | +8% | −12% | 1 | $8M | Undisclosed round$3M, Apr 2026 |
| 62 | One-hour antibiotic sensitivity testing | 14 | +8% | +17% | 0 | $3.6M | Seed$750K, Aug 2026 |
| 63 | Podium for local businesses in Latam | 14 | +8% | +8% | 0 | $125K | Undisclosed round$125K, Jan 2023 |
| 64 | At-home spa, beauty & grooming services marketplace for LatAm | 45 | +7% | +10% | 8 | $2.9M | Undisclosed round$2.8M, Jun 2023 |
| 65 | Malga is an API to accept payments with multiple payment providers | 77 | +7% | +15% | 0 | $8.4M | Series A$5.6M, Feb 2025 |
| 66 | The #1 Market Network for Government Contractors. | 47 | +7% | +15% | 0 | $13.1M | Series A$9.5M, Nov 2023 |
| 67 | We make instant offers to buy homes in India | 142 | +7% | +37% | 0 | $7.2M | Seed$5.8M, Jun 2022 |
| 68 | Whaly is building a self-service analytics platform | 16 | +7% | +33% | 0 | $2M | Seed$1.9M, Jun 2022 |
| 69 | Noom for Southeast Asia | 68 | +6% | +6% | 0 | $2.7M | Non-equity support$2.6M, Feb 2024 |
| 70 | Modernizing hedge fund back office software and services. | 18 | +6% | +6% | 0 | $3.7M | Seed$3.6M, Jun 2022 |
| 71 | Create, launch, and optimize Facebook ads and ads on 10+ platforms | 18 | +6% | −5% | 0 | $2.1M | Seed$2M, Nov 2024 |
| 72 | IP operating software for brands and content companies | 289 | +6% | +19% | 0 | $89M | Series B$48M, Sep 2025 |
| 73 | Pioneering Breast Cancer Diagnostics for a Healthier Tomorrow | 19 | +6% | +6% | 0 | $261K | Seed$136K, Jun 2026 |
| 74 | Low-cost, high-scale EV charging platform for apartments (and more). | 19 | +6% | +6% | 1 | $7.8M | Grant$3M, Feb 2026 |
| 75 | A mobile app. It allows employees to get paid their salary on-demand. | 84 | +5% | −1% | 1 | $64M | Undisclosed round$21.7M, Jun 2025 |
| 76 | Automate finance operations with AI | 22 | +5% | +47% | 0 | $3M | Seed$2.3M, Jan 2022 |
| 77 | Cloud and Container Security Platform | 22 | +5% | +22% | 0 | Seed (before YC)May 2021 | |
| 78 | Decarbonizing the fashion industry | 45 | +5% | +10% | 3 | $17.1M | Series A$15M, Apr 2024 |
| 79 | Offers insurance to customers in a convenient & transparent way | 136 | +5% | +15% | 0 | $6.7M | Seed$3.3M, Nov 2024 |
| 80 | Fair, simple and accessible financial services | 480 | +4% | +15% | 2 | $86.8M | Corporate round$53M, May 2026 |
| 81 | Remote labor for restaurants | 24 | +4% | 0 | $16M | Convertible note$11.3M, Aug 2022 | |
| 82 | B2B e-commerce and fintech platform for traditional proximity stores | 73 | +4% | +3% | 0 | $21M | Series A$12M, Oct 2025 |
| 83 | Simplified digital health insurance for Filipino SMBs | 98 | +4% | +11% | 12 | $6.5M | Seed$6.5M, Jul 2024 |
| 84 | Datlo helps companies increase sales and expand through data | 50 | +4% | −24% | 0 | $838K | Seed$713K, May 2025 |
| 85 | P2P Cross border payments | 25 | +4% | +14% | 0 | $14.5M | Series A$14.5M, May 2025 |
| 86 | Leading wealth management and investing platform in Vietnam | 51 | +4% | +11% | 0 | $8M | Corporate round$6M, Mar 2024 |
| 87 | Building the human layer of AI | 104 | +4% | +33% | 8 | $64.2M | Series B$40M, Nov 2025 |
| 88 | The most magical personal Voice-Led AI English Learning Buddy for Kids | 82 | +4% | +9% | 0 | $125K | YC investment$125K, Mar 2022 |
| 89 | Loan management software for private lenders | 30 | +3% | +76% | 1 | $13.6M | Series A$13.5M, Feb 2026 |
| 90 | Operating system for insurance agencies | 32 | +3% | +10% | YC | ||
| 91 | The fastest way to ship airtight AI | 33 | +3% | +43% | 0 | $19.3M | Series A$14.5M, May 2025 |
| 92 | Track & Boost Your Brand’s Visibility in AI Search | 141 | +3% | +22% | 1 | $2.6M | Seed$2.5M, Sep 2021 |
| 93 | Autonomous team of AI agents that runs the entire hospital operations | 71 | +3% | −9% | YC | $30M | Undisclosed round$21.8M, Oct 2025 |
| 94 | Latin America's Deposits Marketplace for Banks | 73 | +3% | −5% | 0 | $2M | Seed$1M, Apr 2025 |
| 95 | Transforming Mental Health for Corporate Asia | 170 | +2% | +33% | YC | $2.9M | Seed$2M, Feb 2022 |
| 96 | AppX helps social media creators launch their own mobile apps. | 129 | +2% | +30% | 2 | $1.4M | Seed$1.3M, Jan 2022 |
| 97 | fluke is a full-digital mobile operator in Brazil | 46 | +2% | +18% | 0 | $1.1M | Non-equity support$125K, Feb 2022 |
| 98 | The platform for buying, selling and managing residential construction | 50 | +2% | +2% | YC | $8.6M | Seed$8.4M, Oct 2021 |
| 99 | Lattice for Latam with personalized learning and development | 107 | +2% | +1% | 0 | $300K | Seed$300K, Oct 2024 |
| 100 | Open Source Infrastructure for the Financial Internet | 54 | +2% | +10% | 3 | $30.8M | Series A$21M, Jan 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
390 companies were in Y Combinator's Summer 2021 batch (S21); 284 are active.
50 companies posted roles in the last 60 days, led by Stepful (36 roles), Exa (28 roles) and ARQ (24 roles). 85 mark themselves as hiring on YC's directory.
By team growth over 6 months (10+ people): Hirebolt (+100%), Aqua (+93%) and Confido (+89%).
Largest latest rounds in the last 12 months, after their YC batch: Exa ($250M), Slash ($100M) and Turion Space ($75M).