What they do:
World's fastest and most optimal route optimization engine
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HQ: Ontario, CA, United States
Top Developer Tools Startups in California
This list has 465 startups and was last updated on Oct 15, 2026. 133 of them are hiring right now. Biggest hubs: San Francisco (441) and Los Angeles (20). Largest teams: GitLab, PagerDuty, and Algolia. Latest round: Supabase raised $150M (Oct 2, 2026).
465 startupsPage 6 of 13
What they do:
Customer support tool purpose-built for companies that sell APIs
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HQ: Truckee, CA, United States
Blink
Hiring
What they do:
Build fully functional apps with AI.
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HQ: San Francisco, CA, United States
What they do:
Agentic workflows for complex, long running business operations
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HQ: San Francisco, CA, United States
What they do:
No-Code LLM Application / Workflow Builder
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HQ: San Francisco, CA, United States
What they do:
Autonomously scaling environments
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HQ: San Francisco, CA, United States
What they do:
The Agent Analytics Platform
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HQ: Los Angeles, CA, United States
Consus
Hiring
What they do:
The fastest and cheapest way to use AI with ITAR or CUI data.
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HQ: San Francisco, CA, United States
What they do:
Hardware-Aware AI for Embedded Software
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HQ: San Francisco, CA, United States
What they do:
Collaborative AI app builder for teams
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HQ: San Francisco, CA, United States
What they do:
The agent-native serverless cloud
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HQ: San Francisco, CA, United States
What they do:
We give AI agents realtime web context via API
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HQ: San Francisco, CA, United States
What they do:
Cosmic is an AI-powered headless CMS
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HQ: San Francisco, CA, United States
Deepnote
Hiring
What they do:
A better data science notebook.
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HQ: San Francisco, CA, United States
What they do:
Open source agent generation framework
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HQ: San Francisco, CA, United States
What they do:
Unifying how the optical industry does business.
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HQ: Los Angeles, CA, United States
Automat
Hiring
What they do:
Agentic automation that understands context, recovers, and improves.
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HQ: San Francisco, CA, United States
YC W23Growth stage
What they do:
Helps teams work effectively with AI coding agents.
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HQ: San Francisco, CA, United States
What they do:
Generate fast, reliable APIs for any platform
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HQ: San Francisco, CA, United States
Emergent
Hiring
What they do:
AI app builder that turns your ideas into monetizable software.
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HQ: San Francisco, CA, United States
YC S24Growth stage
What they do:
The most powerful sandboxes for AI Agents
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HQ: San Francisco, CA, United States
What they do:
AI app builder for creating and launching iPhone apps
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HQ: San Francisco, CA, United States
What they do:
Encrypted AI with verifiable privacy
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HQ: San Francisco, CA, United States
What they do:
Turn scattered data into one platform for decision-making
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HQ: San Francisco, CA, United States
What they do:
The E2E testing layer for AI-driven development
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HQ: San Francisco, CA, United States
Proliferate
Hiring
What they do:
Do your life's work with agents
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HQ: San Francisco, CA, United States
YC S25Early stage
What they do:
AI agents for E2E testing across mobile & web
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HQ: San Francisco, CA, United States
What they do:
Browser infra for AI agents: sessions, auth, proxies, payments
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HQ: San Francisco, CA, United States
What they do:
API for unlimited, durable, real-time streams
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HQ: San Francisco, CA, United States
What they do:
Earned intelligence for every company
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HQ: San Francisco, CA, United States
What they do:
Better, faster tech vendor research
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HQ: Los Angeles, CA, United States
What they do:
Classify Anything
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HQ: CA, United States
What they do:
Internal developer platform for Terraform, OpenTofu and Helm
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HQ: Los Angeles, CA, United States
What they do:
Building the definitive all-in-one on-device AI productivity tool
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HQ: Los Angeles, CA, United States
What they do:
QA agents that write tests 10x faster with zero maintenance
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HQ: San Francisco, CA, United States
What they do:
The authentication framework for TypeScript
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HQ: San Francisco, CA, United States