Top IT Services Companies in California
We ranked 7 IT service providers in California on client reviews, how many are verified, service focus and profile completeness. Updated October 2026. How rankings work
Providers that secure, run and support a company’s technology.
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Offensive security firm headquartered in Tempe, Arizona, providing penetration testing, red teaming and continuous security testing for enterprises.
No reviews yet
San Francisco, CA
- Cybersecurity
Managed detection and response across an organization's existing security environment.
No reviews yet
Palo Alto, CA
- Cybersecurity
IT support and compliance consultancy serving Alaska, the San Francisco Bay Area, and Washington.
No reviews yet
Walnut Creek, CA
- Managed IT Services
- Cybersecurity
Medical-device software, verification, and connected-product security.
No reviews yet
Irvine, CA
- Custom Software Development
- Software Testing & QA
- Cybersecurity
Test automation, modular QA engineering and game or connected-product testing.
No reviews yet
San Mateo, CA
- Software Testing & QA
- Cybersecurity
San Diego custom software developer building mobile, web, desktop and enterprise applications since 1990.
No reviews yet
San Diego, CA
- Custom Software Development
- Mobile App Development
- Web Development
Custom software, applied AI and connected industrial systems with distributed delivery.
No reviews yet
Roseville, CA
- Custom Software Development
- AI & Automation
- API & Integration Development
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