321 YC Infrastructure Startups (B2B)

321 YC companies fall under Infrastructure, YC's B2B subcategory, across every batch since 2005. Each row shows the one-liner, batch, HQ and status, and links to a reconstruction of the company's YC application in the real form.

Companies
321
Top locations
San Francisco, New York and Mountain View
YC top companies
3
321 reconstructed applications

Read the YC application of all 321 companies

  • Every company's YC application, reconstructed in the real form
  • Filter every batch by industry, country and team size
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The first 100 companies, top companies first

1
CoreOS
CoreOSTopOpen source tools of modern distributed systems.
Summer 2013San Francisco, CAAcquired
2
Fivetran
FivetranTopThe leader in automated data movement
Winter 2013Oakland, CAActive
3
Heroku
HerokuTopEnabling developers to build and run applications in the cloud.
Winter 2008San Francisco, CAAcquired
4
14.ai
14.aiAI engine powering autonomous brands starting with gloglo.com
Winter 2024San Francisco, CAActive
5
AccessOwl
AccessOwlManaging your Employees' Access to SaaS
Summer 2022Berlin, Berlin, GermanyActive
6
Activeloop
ActiveloopDatabase for AI
Summer 2018Mountain View, CAActive
7
Aden
AdenOpen source agent generation framework
Winter 2020San Francisco, CAActive
8
AeroFS
AeroFSSecure Enterprise Collaboration.
Summer 2010Palo Alto, CAAcquired
10
AgentMail
AgentMailEmail Inboxes for AI Agents
Summer 2025San Francisco, CAActive

That is 10 of 321.

Every company below has its YC application reconstructed in YC Insights. Create a free account to read them all.

Read all 321 applications
11
AgentPhone
AgentPhonePhone Numbers for AI Agents
Spring 2026Active
12
Airtrain AI
Airtrain AINo-code data curation for LLM fine-tuning and evaluation.
Summer 2022San Francisco, CAInactive
13
Airweave
AirweaveThe open-source context retrieval layer for agents
Spring 2025San Francisco, CAActive
15
Amika
AmikaInfra to build your own software factory
Fall 2025New York, NYActive
16
Apollo
ApolloApollo helps engineering teams accelerate delivery
Summer 2011San Francisco, CAActive
18
AppHarbor
AppHarbor.NET Cloud Platform as a Service
Winter 2011San Francisco, CAInactive
19
Apportable
ApportableiOS porting
Winter 2011San Francisco, CAAcquired
20
Aptible
AptibleThe No Infrastructure Platform as a Service
Summer 2014New York City, NYAcquired
22
Aravolta
AravoltaSoftware to monitor, control, and optimize data centers.
Spring 2025San Francisco, CAActive
23
Archal
ArchalAPI sandboxes, built for AI agents
Summer 2026San Francisco, CAActive
24
Archil
ArchilThe high-performance file system that connects AI to data
Fall 2024San Francisco, CAActive
25
Ardent
ArdentDatabase sandboxes for Agents
Spring 2026San Francisco, CAActive
26
Ardis AI
Ardis AITransform your text data into a searchable knowledge graph
Winter 2020Mountain View, CAInactive
27
Armory
ArmoryContinuous Deployment at any scale, for all developers.
Winter 2017San Mateo, CAAcquired
28
Arpio
ArpioRecover from any outage in 10 minutes or less.
Winter 2021Durham, NCActive
29
Arroyo
ArroyoCloud-native stream processing
Winter 2023Berkeley, CAAcquired
31
Artillery
ArtilleryThe complete production quality platform. AI-powered E2E testing,…
Summer 2021Limerick, County Limerick, IrelandActive
32
Ascii
AsciiThe best cloud VMs for billions of agents
Fall 2026Paris, Île-de-France, FranceActive
33
AssemblyAI
AssemblyAIThe best way to build Voice AI apps
Summer 2017New York City, NYActive
34
assistant-ui
assistant-uiOpen Source React.js Library for AI Chat
Winter 2025San Francisco, CAActive
35
Atomized
AtomizedEnabling teams to deploy without needing a cloud expert
Summer 2020Charlotte, NCInactive
36
Autumn AI
Autumn AIStalk your prospects at scale.
Winter 2026San Francisco, CAActive
37
Beam
BeamAI-Native Cloud Platform
Winter 2022New York, NYActive
38
Bitmovin
BitmovinPowers OTT online video providers with video developer tools.
Summer 2015San Francisco, CAActive
39
Bitnami
BitnamiThe App Store for Server Software
Winter 2013San Francisco, CAAcquired
40
Bitrise
BitriseHosted Continuous Integration and Delivery for mobile apps
Winter 2017Budapest, HungaryActive
42
Bland AI
Bland AIThe enterprise platform for AI phone calls
Summer 2023San Francisco, CAActive
43
Blockscope
BlockscopePalantir for Web3
Summer 2022New York, NYActive
45
bluedoor
bluedoorThe world's data, ready for AI
Summer 2024Seattle, WAActive
47
Brickanta
BrickantaAgentic AI for Society Builders
Fall 2025Stockholm, Stockholm County, SwedenActive
48
BricksAI
BricksAIStreamlining LLM application management for enterprises
Summer 2022San Francisco, CAInactive
50
Bun
BunBun is an incredibly fast all-in-one JavaScript toolkit
Summer 2019San Francisco, CAAcquired
51
Buró de Ingresos
Buró de IngresosThe Work Number for LatAm
Summer 2021Mexico City, CDMX, MexicoActive
52
Butter
ButterEmbedded Sandboxes for Agents
Winter 2025San Francisco, CAActive
53
Cakework
CakeworkAPI that adds cloud hosting to any developer platform
Winter 2023Seattle, WAInactive
54
Captain
CaptainGive AI agents accurate knowledge search that scales
Winter 2026San Francisco, CAActive
55
Cascade
CascadeDistilling Proprietary Intelligence
Winter 2026San Francisco, CAActive
56
Caution
CautionHosting platform for software you can't afford to have hacked
Summer 2026George Town, George Town, Cayman IslandsActive
57
Cedana
CedanaFast, reliable, reproducible AI with GPU live migration
Summer 2023New York, NYActive
58
Celest
CelestThe Vercel of Flutter
Winter 2024San Francisco, CAInactive
59
Cerebrium
CerebriumServerless Infrastructure Platform for AI
Winter 2022New York, NYActive
60
Chamber
ChamberThe AIOps Agent for ML Teams
Winter 2026Seattle, WAActive
61
Citus Data
Citus DataReal-time. Big data. PostgreSQL
Summer 2011San Francisco, CAAcquired
62
Clew
ClewUnified file system for the cloud.
Summer 2020Toronto, ON, CanadaAcquired
64
Cloudkick
Cloudkick
Winter 2009San Francisco, CAAcquired
65
Clustrix
Clustrix
Winter 2006San Francisco, CAAcquired
66
Codag
CodagThe AI gateway for cheaper, faster, permissioned agents.
Summer 2026San Francisco, CAActive
69
Context.dev
Context.devWe give AI agents realtime web context via API
Summer 2026San Francisco, CAActive
71
Coris
CorisAI risk and ops platform for Payment Processors, Banks, SaaS…
Summer 2022San Francisco, CAActive
74
CTGT
CTGTThe deterministic layer for frontier intelligence
Fall 2024San Francisco, CAActive
75
Cumulus Labs
Cumulus LabsThe Fastest Multimodal Inference OS
Winter 2026San Francisco, CAActive
76
Darkgrade
DarkgradeLet your camera understand the world
Fall 2024New York, NYActive
77
Data Mechanics
Data MechanicsSpark-on-Kubernetes Data Engineering Platform
Summer 2019Paris, Île-de-France, FranceAcquired
78
David
DavidBuild and host internal tools
Winter 2023New York City, NYActive
79
Decawork
DecaworkTraining company-specific models that approve AI actions.
Summer 2026San Francisco, CAActive
81
Dedalus Labs
Dedalus LabsCompute substrate for AI agents
Summer 2025San Francisco, CAActive
82
Denormalized
Denormalizedserverless platform for real-time data
Summer 2022San Francisco, CAInactive
83
Dialogus
DialogusThe AI-native contact center
Summer 2026San Francisco, CAActive
84
Didit
DiditInfrastructure for identity and fraud.
Winter 2026San Francisco, CAActive
85
Docker
DockerSoftware development platform.
Summer 2010San Francisco, CAActive
86
Documents.Me
Documents.MeClient-side encryption for your devices and the cloud.
Winter 2012Santa Clara, CAInactive
87
Dojah Inc
Dojah IncPrevent Fraud and Onboard Users Faster
Winter 2022Lagos, LA, NigeriaActive
89
Downlink
DownlinkMake your LLMs 3x faster.
Winter 2024San Francisco, CAActive
90
Drip
DripAI that books meetings for you
Spring 2026San Francisco, CAActive
91
Dyte
DyteReal-time audio & video SDKs, ready to launch 🚀
Winter 2021Bengaluru, KA, IndiaAcquired
92
Edviro
EdviroAI That Operates Energy Infrastructure
Summer 2026San Francisco, CAActive
93
Encord
EncordThe data layer for physical AI
Winter 2021London, England, United KingdomActive
94
Engines
EnginesSetup any repo with one command
Winter 2024San Francisco, CAInactive
96
Etleap
EtleapEtleap is an ETL solution for creating perfect data pipelines.
Winter 2013San Francisco, CAActive
97
Eventual
EventualBuilding the AI data engine for any modality and scale
Winter 2022San Francisco, CAActive
98
Executor
ExecutorThe open source tool gateway
Summer 2026San Francisco, CAActive
99
Expanse
ExpanseUnlock wasted GPU capacity.
Spring 2026San Francisco, CAActive

The other 221 companies

Every remaining company in this list, A to Z. Each link opens the company's public page.

ExpoFamiliarFathomDBFernFirebaseFlightcontrolFlowFlowbotFlowDeployFlowtelFly.ioFreestyleFreshpaintFuzzbuzzGalaxyGeneral InstinctGitCafeGlasskubeGlideGoScaleGraiHatchetHegel AIhiloopHopperHydraHyperspellImgixImpreziaIncidentFoxIndexicalInduction LabsInfluxDatainfra.newInkboxInscribeInterfazeInthIOMETEJido MapsKairosKERNELKeyDBKlaus AIKugelAudioKV CashLanceDBLibrar LabsLimrunLLM StatsLogiblockLuelLuminalmachine0Magicflow 𐂂MagmaMantisManufact (formerly mcp-use)MaritimeMarkovMavenMem0MetamanagementMetisMezmoMiddlewareMindsDBMinefoldMinicorMireyeMiruMiso LabsMochaModaModelenceMorphMorphikMozart DataMundo AIMuxMysticNarratorNeosyncNeptune.ioNestyboxNetBeezNetmakerNextopNimbusNiniteNullstoneNuntiusOdigos Technologies Inc.OktetoOllamaOneTriangleOpenMeterOpenReplayOpenVectorOpslaneOrchestraOrthogonalOutlitOwayOximyPachydermPangolinParakeyParallel UniverseParaQueryParasmaPeer5PgDogPhoneSysPipekitPipelineDBPipeshiftPiris LabsPixatePluralithPluttoPointOnePorterPreclusioPrembly (formerly Identitypass)primitiveProjectXPromptProtocol LabsProtonetProvisionProxinoPulsePylonQuestDBQuicknodeRaven TechRDashRealmRedspreadReflexRellingReplicateReployRespanRethinkDBRevylRiftenRightNowRivetROERootlyRowndRunAnywhereRunRLRyvns2.devSalusSatsumaSazabiSciloopScoutScratch DataSF TensorShapedShofoShuttleSieveSignadotSigNozSimpleHashSingleStoreSixtyfourSkyvernSlashAuthSlauth.iosmol machinesSpeedscaleSpekoSRE.aiSSTStableBrowseStackMachineStreamdalSunpiaSupabaseSuperAPISvixSynnaxSynthTeleportTensorPoolTerarkTermiiTerminal UseTerracotta AITexel.aiThe Token CompanyThunder ComputeTipeTouchmarkTrieveTrue3D LabstruthsystemsUbicloudVersoriVibrant LabsVidpressoVirtualminVislyWarrantWasmerWatoWaycoWindmillWingbackWordwareZencoderZeroDevZeroEntropyZibra Labs

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About this list

This list is part of Round Funded, an investor database and outreach platform for founders. It covers 60,000+ active VCs, angels, family offices and accelerators with verified contacts, lets you send pitches from your own Gmail, and includes a free Data Room for your raise.

Frequently Asked Questions

How many Y Combinator companies are in Infrastructure (B2B)?

This directory lists 321 YC companies in Infrastructure (B2B), out of 6,207 across every batch since 2005. The count updates when the directory is refreshed, and every one of them is on this page with a link to its public profile.

Are the YC applications on these pages real?

No. YC keeps submitted applications private. Every application linked from this list is a reconstruction: the real YC form questions, answered from the company's public data. The Company section is free on each page; the rest opens in YC Insights.

Which companies on this page are best known?

CoreOS, Fivetran and Heroku lead the table above. YC marks 3 of the 321 companies here as top companies, its own list of the highest-valued and highest-revenue alumni.

How do I use this list when applying to YC?

Pick five companies on this page whose product is closest to yours, read their reconstructed applications side by side in YC Insights, and note how each answers the same question. Then write your own answers to that standard.

Where does this data come from?

From YC's public company directory, refreshed by batch, with each company's status, industry and location as YC reports them. Round Funded adds the reconstructed application and the founder profiles; nothing private is published.

What is Round Funded?

Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.