Infrastructure Startups funded by Y Combinator (YC) in the San Francisco Bay Area 2026

Fivetran automates data movement out of, into and across cloud data platforms. We automate the most time-consuming parts of the ELT process from extracts to schema drift handling to transformations, so data engineers can focus on higher-impact projects with total pipeline peace of mind. With 99.9% uptime and self-healing pipelines, Fivetran enables hundreds of leading brands across the globe, including Autodesk, Conagra Brands, JetBlue, Lionsgate, Morgan Stanley, and Ziff Davis, to accelerate data-driven decisions and drive business growth. Fivetran is headquartered in Oakland, California, with offices around the world. 

Compresr provides an API that compresses LLM context without losing what matters. It’s a drop-in for agents and RAG that cuts token costs and improves accuracy.

Shofo builds large-scale social media training datasets by collecting, labeling, and enriching public content for pre-training and fine-tuning AI models. Our indexes continuously collect and update every post across hard to access social media platforms. Companies use Shofo to avoid building their own data collection and processing systems and spending months turning unstructured social content into model-ready data. We started with TikTok and are expanding across every major social platform.

Chamber puts your AI infrastructure on autopilot. Our agentic AI enabled platform orchestrates, governs, and optimizes your AI infrastructure so teams can run ~50% more workloads on the same GPUs without manual intervention. It operates like an autonomous infrastructure team: continuously monitoring GPU clusters, forecasting demand, detecting unhealthy nodes, and reallocating resources in real time to where they create the most impact. Your ML teams move faster, infra waste drops, and GPU bottlenecks disappear.

Edge AI is inevitable, but shipping it is painful: every device class behaves differently, runtimes vary, models are huge, and performance collapses under memory/power constraints. RunAnywhere turns that into an enterprise-ready workflow: one SDK to run models on-device, plus a control plane to manage models, enforce policies, and measure outcomes across thousands of devices.

RLVR changed the game for post-training. We're here to build and supply the next-generation of coding data and RL environments using model checking languages and formal verification. In a world where solid coding data is becoming increasingly sparse, Haladir provides the data and environments needed to build the next generation of coding models.

Didit is an AI-native, developer-first identity verification platform that makes KYC, AML, and fraud prevention instant, flexible, and transparent, with a seamless user experience and more than 70% lower costs.

Luel is a sourcing and licensing platform for rights-cleared multimodal training data at scale. We work with frontier AI teams to provide high-quality bespoke data collections and off-the-shelf datasets.

Captain delivers the most accurate general-purpose retrieval engine for unstructured data. Connect file stores and effortlessly retrieve knowledge with much higher accuracy than RAG (Avg: 78% → 95% + citations).

Nivara gives engineering leaders visibility into how humans and AI build together, helping teams spot bottlenecks, measure impact, and turn AI adoption into real outcomes. We're building the much needed copilot for Engineering Managers and empower every team to work intelligently with AI.

Hyperspell (YC F25) gives AI agents memory. It connects to tools like Slack, Gmail, Notion, and Drive so agents can recall, reason, and remember across company knowledge. Developers use Hyperspell’s API to turn disconnected agents into AI coworkers that understand their work. Conor and Manu founded Hyperspell after building their own workplace agent and seeing how limited AI is without memory. They have over 15 years of experience in machine learning and have scaled API-based products to $30M ARR.

S2 is a serverless datastore for real-time, streaming data. The more we worked on data systems, the more we felt like there was a missing building block. The seamless experience of object storage simply did not exist for durable streams – so we set out to fix that! S2 reimagines streams as an unlimited and access-controlled web resource. Like if Kafka and S3 had a baby. - Building agents? Use granular streams to persist context in real time, make workflows auditable, and coordinate between agents. - Publishing fast-moving data? Streams support high fanout and can be accessed directly over the internet, so they are a great fit for broadcasting real-time feeds. - Sandboxing? Emit to per-instance streams, and read history or live events just as easily. - Local-first and multiplayer experiences? Propagate updates reliably and efficiently. Stop dealing with clusters, and start streaming.

We build infrastructure enabling AI agents to reliably perform complex tasks in production

Truth Systems provides a compliance agent to govern the use of generative AI. It translates operational policies into intelligent, real-time guardrails that monitor every AI interaction. This empowers companies to proactively block non-compliant actions and align access to AI tools with user competency. By eliminating the risks and operational blind spots associated with uncontrolled AI adoption, our platform enables enterprises to fully leverage the technology's potential without compromising security. We are establishing the new standard for AI governance, building a future where every professional can innovate safely and confidently.

Kernel is crazy fast, open source infra for AI agents to access the internet 🧠🕸️ - Built on unikernels for crazy fast cold starts and low resource usage - Sub-150ms cold starts on managed headful browsers - Built-in stealth mode with residential proxies and automatic CAPTCHA solving - Full observability: session recording, live view, and full logs - Persistent sessions that maintain cookies and auth across invocations - Native support for all browser and computer use frameworks - SOC 2 compliant and HIPAA-ready Trusted by Cash App, Rye, and 1000+ others. Backed by Accel & Y Combinator (S25).

DeepAware builds an AI-driven automation system for GPU-intensive data centers. Our reinforcement-learning scheduler, real-time market integration, and unified dashboard slice energy waste by up to 30%. Coming soon: autonomous “robot-hand” inspections and maintenance to enable 24/7 operations with minimal staff. More info: https://deepawareai.com/ Jobs/Internship: https://www.deepawareai.com/careers

You built the demo in a weekend. Now you need auth, a prod-grade database, real-time events, AI observability, cron jobs, email, monitoring… and you needed them yesterday. We spent a decade at our previous startup, building a platform while scaling to millions of users and customers like Meta & Netflix. Now we put that into an open-source framework, so others wouldn’t have to do the same from scratch. Modelence is a batteries-included framework that abstracts away boilerplate so you can just focus on building your product logic and nothing else - it’s like Next.js + Vercel + Supabase on a single platform, built for full-stack TypeScript. Shipping production apps is much harder than building a prototype that runs locally and 95% of all production apps share the same building blocks. We did a massive amount of work on our previous platforms that was not specific to our product, and we’ve created Modelence to abstract that away: - Authentication - Database setup - Hosting / CDN - AI integration (LLM observability, prompts) - Real-time events - Cron jobs - Email service - Monitoring - Analytics - Admin dashboards Andrej Karpathy recently posted about this same exact problem: https://x.com/karpathy/status/1905051558783418370 and explained it further in his YC AI Startup School talk: https://youtu.be/LCEmiRjPEtQ?feature=shared&t=1940

AgentMail is the email inbox API for AI agents. It gives agents their own email inboxes, like Gmail does for humans.

Janus automates AI evaluations by using high-fidelity simulation environments, catching failures in reasoning, compliance, tool usage, and performance. The resulting datasets benchmark products and feed post-training loops to continuously improve performance over time.

Aravolta provides a single pane of glass software for data centers to increase uptime, reduce costs, and improve performance. A single utility node onboards every asset within an hour and detects hardware failures, hotspots, and other issues. It also generates reports on important metrics like Power Usage Effectiveness (PUE), energy metering, resource utilization, and much more.

Morphik is open-source multimodal search for AI apps. We're used by customers ranging from space-tech teams searching across research papers to developers building brokerage agents.

RunRL improves LLMs and AI agents with reinforcement learning. Do you have a model that needs to get better at a certain task? Are you tired of messing around with prompts? Do you spend a lot of money on observability, and wish that all this data could let your model self-improve? Well, head on over to RunRL.com, and see what we have to offer! If you give us a model, a prompt, and a reward, we’ll make your model’s reward go up.

AI models are terrible in non-English languages because it's nearly impossible to find training data in other languages. So, we're building the world's largest and highest-quality multilingual data library.

assistant-ui helps frontend developers add AI chat to their apps. Our product is used by several dozen companies, like LangChain, Stack AI, Browser Use, and Athena Intelligence. We're building an open source Typescript/React library and a backend as a service, with first class integrations into popular agent frameworks like LangGraph and Vercel AI SDK.

AfterQuery is a research lab (backed by Y Combinator) investigating the boundaries and capabilities of artificial intelligence through novel datasets and experimentation. We believe that pushing the frontiers of AI requires both rigorous scientific inquiry and exceptional human data.

Flowtel is building the next generation operating system for hospitality, powered by modern AI agents that can handle everything from booking to room service.

Reliability on autopilot. Free you team to build what's next.

Enterprises are paralyzed by the risks of deploying generative AI. Traditional methods like RAG and fine-tuning are brittle, expensive, and fail to prevent costly hallucinations or guarantee compliance in high-stakes environments. This lack of trust stalls innovation and blocks ROI. CTGT ensures strict, auditable adherence to your policies on the fly. We deliver defensible audit trails and remediate noncompliant model behavior, so outputs become more aligned with company policies over time, combating data and model drift. CTGT is backed by Google's AI fund (Gradient), General Catalyst, and luminaries like Paul Graham. We provide the control and confidence necessary to unlock the full potential of enterprise AI.

Revyl is a AI-native mobile testing platform that automatically catches and triages bugs before they reach production.

You share production/eval traces for your AI software and sync your code. Synth asynchronously runs experiments to develop, improve, and maintain your software and hands code/prompts/models off to your team. Designed for teams building vertical AI software/agents.

Archil transforms S3 buckets into a 30x faster, unlimited, local disk. Archil enables AI, analytics, and serverless applications to instantly access massive data sets without waiting for data transfer. Researchers use Archil for shareable, local storage of data set and model versions that never runs out of capacity.

Self-serve GPUs in VS Code with persistent storage, snapshots, and hot-swappable hardware, with prices 80% lower than AWS.

Miru makes it easy for robotics teams to manage, version, and deploy robot configurations. Developers use our well-documented APIs and UI components to automate configuration updates for both engineers and operators. In the long term, we're building software infrastructure to accelerate the automation of the physical world.

Opslane is a developer-first Kubernetes delivery platform. Connect your repo and get previews, safe rollouts, and instant rollbacks — no YAML, no ops team required.

Ben and Jacob met in Calculus class in 10th grade, and tried founding a startup in high school — it didn’t go anywhere. During high school, Ben lead the frontend team for the World Health Organization’s COVID-19 App Team. After high school, Jacob went to Apple and Ben went to college. When there was an opening on his team, Jacob had Ben apply, and Ben left UChicago to go work at Apple. They spent about 2 years at Apple as Senior Engineers in the Conversational Engineering Department, before leaving to found Freestyle. Freestyle is directly inspired by what they saw as their failures of the tech they worked with at Apple.

Pipeshift is a modular orchestration platform for building with open-source AI components — embeddings, vector databases, LLMs, vision models and audio models — across any cloud or on-prem. Enterprises get to deploy their AI workloads in production faster and more reliably. Additionally, as we see more model and hardware architectures coming in the market, Pipeshift future-proofs the infrastructure investments by offering flexibility through their modular MLOps stack that allows enterprises to bring down their GPU infrastructure costs without any additional engineering efforts on their end.

Mem0 provides a memory layer for LLM applications, enabling them to remember and learn from user interactions over time.

AI Agents have arrived. They are powerful enough to read, plan, and act across your everyday life and work. The question is no longer whether they can run canned demos to check the weather, it’s whether real teams can rely on them for critical work. We optimize for adoption over spectacle: useful, accountable systems that help top professional complete real tasks. Wordware is backed by Spark Capital, Felicis, and Y Combinator, with a $30M seed round. Our beautiful, historic San Francisco office sits in the shadow of the Golden Gate Bridge, it’s full of plants and radiates innovation and calm. We genuinely love working together. At lunch we talk about alignment and AI consciousness, we have surfboards in the office ready to use, we take walking meetings on the beach and hang out after work at the bar or climbing wall. We work really hard because we care deeply about what we do. Sauna is Wordware’s AI workspace for professionals. Think ‘Cursor for Knowledge Work’ and you’re halfway there. With explicit permission, it connects to tools like Gmail, Calendar, Slack, and thousands more, to gather the right context to move your work forward. It learns who you are, drafts and refines your documents, presentations, and datasets, researches across the web and your org’s internal knowledge, summarizes long threads to cut through the noise, proposes next steps, even acts on your behalf when enabled. You can work with Sauna live, side-by-side, or schedule jobs to run automatically in the background, with clear permissions and easy off-switches. Sauna brings the power of AI Agents to all professionals.

We work on benchmarking and improving the long-horizon capabilities of AI Agents. We build out specialised environments to improve the long-horizon capabilities of browser and computer use agents.

Downlink is a platform that continuously improves your AI. Boost rate limits, slash latency, and raise accuracy.All through one simple API.

ROE AI solve risks and compliance problems for financial industry.

14.ai is a Zendesk alternative built from the ground up for AI agents.

What if you could build web apps as easily as you make a Figma design or edit a Google Doc? Enter Mocha. We've reimagined app development with a state-of-the-art coding agent that builds for our users. Want to launch that app idea? Need to build something for your community? Looking to prototype faster? Start here. We've removed the barriers between idea and execution. Our mission is to empower everyone to build for the web, our vision is personal software.

Skyvern helps companies automate browser based workflows using LLMs and Computer Vision, fully automating manual workflows and replacing brittle or unreliable scripts. Examples include: 1. Automating materials procurement from commerce websites 2. Completing complex multi-step workflows (ie getting an insurance quote from Geico.com) 3. Automatically logging into portals and downloading invoices 4. Navigating legacy content systems to do data extraction or data entry

Epsilla is an all-in-one platform for building AI agents powered by your private data and knowledge. Easy to use for domain professionals, deeply customizable for AI experts, and fully equipped for enterprise customers with security, scalability, and integration.

Artie is software that streams data from databases to data warehouses in real-time. Today, most companies run their ETL process every few hours or overnight, so their data warehouse is always out of date; with Artie, the warehouse always has live production data.

Easily build & scale AI agents, functions, stateful services, and more. Open-source & self-hostable.