B2B Software and Services Startups funded by Y Combinator (YC) in Seattle 2026

Clearly AI automates security and privacy reviews with AI. We performed hundreds of reviews at Amazon and Moveworks and now we're building the product we wish we had. Our users complete reviews in minutes instead of days. Emily and Joe are technical co-founders and senior engineers. We met in 2019 while working on an Alexa security review.

Manifold is revolutionizing the spot freight procurement process for Carriers, Brokers, and Shippers. Our inaugural product transforms the booking process for spot shipments, significantly reducing empty miles and increasing revenue. We do this by aggregating spot shipment opportunities from a variety of shipper and brokerage sources into a single location. Andrew and Oliver bring deep domain expertise of freight from their pivotal roles at Convoy, where they were engineering leaders automating processes that were scaled to handle over 10,000 weekly shipments. This background has been instrumental in shaping Manifold's innovative approach. In just two months since launching Manifold has achieved $5,100 in monthly revenue, showcasing the pressing demand for our product. Manifold is poised to transform this $100+ billion industry. Not only will we streamline spot freight procurement operations but we will also redefine the industry's cost structure for the better.

Terrakotta is a power-dialer that lets sales reps leave AI-generated voicemails. Our first customers are Commercial Real Estate brokerages that use Terrakotta to clone their brokers voices, dial prospects and when no one answers, leave an A/B tested, personalized voicemail that gets a callback.

VetRec automates the process of taking clinical notes for veterinarians in a matter of seconds. Veterinarians should just review clinical notes, not spend time creating them. A visit with a pet is precious and 100% of the focus should be spent on the pet, not on notes. VetRec is the veterinarian's best friend.

Talc helps hospitals pull events and data out of messy EHRs.

Boundary is building BAML -- a programming language to build AI agents. We used to code in assembly, and moved on to C. From C, we moved on to higher level languages like Python. Now we are going from Python to natural language. What does the code look like when 50% of the business decisions is decided by an AI agent / prompts? How do you test these AI components? We made BAML to address these problems. BAML helps has built-in tools to test, observe, and work with structured LLM outputs / tool calling natively in the language 10x faster. With BAML you can also instantly parallelize LLM Calls, or react to certain events or changes in your pipelines, without having to write any boilerplate. It's like using 'React' for AI. BAML code can used from any other language -- providing a standardized way to organize and declare any LLM or AI code.

Matano is a modern SIEM, built for cloud-first security teams. It replaces traditional SIEM databases like Splunk or Elastic with a cybersecurity platform built on top of a cost-effective Security Data Lake.

Aurelian automates non-emergency calls for 911 centers. Our AI-powered operator instantly routes, triages, and resolves calls so citizens get exactly what they need and 911 dispatchers get to focus on emergencies. Upwards of 80% of total call volume faced by public safety agencies are administrative calls e.g., citizens trying to pay parking tickets or reporting a power outage. Aurelian lessens this burden and lets 9-1-1 dispatchers deal with actual emergencies. To date, Aurelian has automated hundreds of thousands of calls and sent over 10,000 emergent calls (that typically would've sat on hold) to the 911 line to be handled immediately.

Intuned is a code-first browser automation platform with an AI agent that builds and maintains your automations. Developers use Intuned to deploy scrapers, RPAs, and crawlers as production-ready TypeScript or Python projects — with stealth, CAPTCHA solving, proxies, auth, and scheduling handled out of the box. The agent builds projects from a prompt, fixes failed runs, and can self-heal automations autonomously when websites change.

Designers and product managers are often locked out of prototyping on top of their existing product. Security policies, large code base, and complex build setup all stand between the promise of code-first front-end design and reality. The Chordio Workbench helps non-technical team members prototype new experiences on top of their existing products even when they don’t have access to the source code. The full workflow runs in Claude Code on your local machine. It starts with cloning the front-end of the product into the workbench repository directly from the browser and compiling it into code a coding agent can work with. This means anyone can start prototyping in minutes without having to worry about a complex environment setup. The Workbench includes agent skills to help ensure prototypes meet team standards, are backed by research, and presented to stakeholders with clarity.

The platform powering human like phone calls at AI speed

Instant Labs started in 2005 by building the fastest domain search engine on the internet: https://instantdomainsearch.com. People have performed over 2.5M searches and purchased 250K domains with our free tool.

Uberduck makes tools high-quality audiovisual content creation tools for product companies, brands, agencies, and musicians. We offer audio generation, image generation, and video generation functionality, including enterprise workflow APIs to power end-to-end video creation experiences. Vocal samples and full songs produced by our text-to-speech, text-to-singing, text-to-rapping, lyric video generation, and voice conversion technologies power: - AI remixes and original songs for musicians ranging from hobbyists to the largest DJs in the world. - Personalized musical content in marketing campaigns. - A variety of music-related consumer experiences built on top of our APIs.

Strac is an agentless Data Discovery (aka DSPM - Data Security Posture Management), Data Classification & DLP (Data Leak Prevention) that automatically discovers, classifies and remediates sensitive data (alert, label, redact, mask, block, delete). Strac protects SaaS, Cloud, Gen AI, Browsers, On-Prem and Endpoints like O365, Slack, GDrive, AWS, Salesforce, ChatGPT, Jira, Mac, Zendesk, Azure, On-Prem (On-Prem, MS SQL SAP) and 40+ integrations. Strac protects enterprise companies like UiPath, Databricks, thredUP, B Capital, Crypto (dot) com!

Awtomic powers DTC brands with an easy-to-use subscription management and discovery platform. Starting with a Shopify app, we'll give merchants the subscription product power of premium subscription brands like Dollar Shave Club and Ipsy. As we grow our support for more eCommerce platforms and merchants, we'll help customers discover new brands through cross-sells and make it easier for them to manage their subscriptions in one place.

Our mission is to empower the world’s hiring teams to grow engaged, high-performing organizations - by delivering human connection at scale through innovative technology, commitment, and fairness. High-volume hiring is extremely broken - it is inefficient, ineffective, and biased. Our mission is to fix what is broken. We believe great hiring processes are centered around quality conversations between candidates and employers and a future where every candidate’s journey starts with a conversation - a future where candidates are considered without bias or archaic artifacts like resumes and cover letters.

Latchel is the only end-to-end platform that automates maintenance coordination and delivers best in class resident amenities. We service over 80,000 homes across over 400 customers in all 50 states of the US. We’re growing rapidly and need a Product Designer to continue our rapid growth trajectory.

Worklytics identifies leading drivers of employee engagement, without the need for repetitive surveys. It does this by passively analyzing anonymous collaboration data, in tools like Google Workspace and Slack, and detecting patterns that lead to greater employee satisfaction. Worklytics uses these insights to promote positive organizational change by proactively nudging leaders and managers.

Mason is the fastest way to take smart devices from idea to end user. Whether building a single-use device from scratch or scaling a line of smart products, with Mason it’s 20x faster and 10x less costly to build, deploy and scale. Digital transformation is a modern requirement but operating a hardware-dependent initiative is hard – thousands of hours and millions of dollars are at stake. The Mason Smart Device Platform is the only fully managed infrastructure for developing and delivering dedicated devices. It offers flexible usage-based pricing for fleets of devices and manages the underlying complexity of all associated backend services, making software delivery on a smart product line—whether it’s a tablet, wearable or new form factor—as simple as delivering software in the cloud. This frees innovators to focus on what matters: application development, feature specification and UX. Granular access to add, remove or lock down capabilities makes it possible for highly customized products to be built as envisioned. Mason offloads hardware investment risks and logistics, including inventory procurement, warehousing and supply chain management. With options like zero-touch provisioning, devices can work perfectly out of the box without end user intervention. Remote fleet management, troubleshooting and automated software updates by Mason ensure security and positive end user experiences. Organizations of all sizes rely on Mason to bring innovations and hundreds of use cases to market without reinventing the wheel. Smarter from start to finish with Mason.™ AWARDS * 2023: Best Places to Work & Best Startups to Work For, Built In Seattle * 2022: Best Places to Work & Best Small Places to Work, Built In Seattle * 2022: IoT Health & Wellness Innovation of the Year, IoT Breakthrough * 2022: Bronze Stevie® Award - Emerging Technology, The 2022 American Business Awards® * 2021: Deloitte Technology Fast 500™, Deloitte * 2019: Tech Impact Awards, Mobile - Silver, Seattle Business magazine Follow us on LinkedIn | https://www.linkedin.com/company/mason-america/

Dyspatch is an AI-powered communications platform that transforms how teams build and manage transactional email at scale. Our platform uses AI to accelerate email creation — from generating and refining content to automating localization across 300+ locales — so your Product, Marketing, and CRM teams can ship polished, dynamic emails without touching code or waiting on developers. A centralized hub for creation, approval, and publishing, Dyspatch connects directly to your existing cloud email provider or messaging service. Upload your templates in minutes, and let AI handle the heavy lifting: optimizing copy, personalizing at scale, and streamlining the entire review-to-send workflow. Built for teams that move fast. No devs required.

RescueTime helps you set boundaries, protect focused work time, and achieve work/life balance by shedding light on how you spend your time, improving your focus, and helping you find more time for the things that matter most. We are a distributed company with members spread throughout the United States.

OpenPipe is an SDK that abstracts away fine-tuning custom models. We capture your existing provider’s prompt-completion pairs in the background and use them to create a new model that is faster, cheaper and often more accurate than the original.

highlight.io is the open source, full-stack monitoring platform. With just a few lines of code, Highlight makes it easy to understand what's slowing down your users and swiftly address errors and regressions on your web app. Imagine that you have a customer reporting an issue on your web app. With highlight.io, you can playback their exact interactions to reproduce the bug and get notified of any future errors that could happen. That being said, we’re just getting started! We have plans to go way deeper into your observability stack to give you all of the visibility you need. Join us on this journey: - Star us on GitHub (https://github.com/highlight/highlight) to keep up with releases and news. - Join our Discord (https://highlight.io/community) to share product feedback and thoughts.

Worksphere helps companies manage a hybrid workplace where employees work from the office and from home. We allow employees to reserve a desk, know who will be in office, and better coordinate in-person meetings. Companies can let go of unused office space and save money.

We build software to help restaurants manage their third-party delivery online orders.

Shelf Engine helps businesses increase sales by accurately predicting the perfect amount of perishable goods to order, thus reducing food waste.