Top Software Development Companies in California

Between them, the 54 software development companies on this page cover web development (20), android (19), mobile app development (18) and web design (17). They also list work in Los Angeles and Southern California. 54 of them have written a profile you can read before you get in touch.

1. =24

   

   Blue Coding

   Consumer Products & Services · Information Technology · eCommerce

   Blue Coding helps companies in the United States and Canada hire software engineers based in Latin America.

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   Why #24 (shared): Address in California · In business 10+ years, as stated on its own website, read 28 Sept 2026

   Not yet on record: client reviews, vetting.

2. 26

   

   EffectiveSoft Corporation

   Mobile App Development · Custom Software Development · iOS App · Also in United States of America

   EffectiveSoft Corporation is a software engineering company that builds and maintains products for regulated and data-heavy industries.

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   Why #26: Based in San Diego, California, USA · ISO 27001 · Team of 300+, as stated on its own website, read 6 Oct 2026

   Not yet on record: client reviews, vetting.

3. Also listed, not yet ranked. We hold nothing checkable on these yet that ranks them here: no client review, vetting, award, expert review, or fact stated on their own website (and on a place ranking, where they are based). They follow in order of their TrustList Score. How TrustList ranks · Get vetted, free
4. –

   

   1969 Communications

   Arts, Entertainment & Music · Retail · Industrial · Also in Washington and Los Angeles

   1969 Communications is a system integrator based in Los Angeles, California, with more than two decades in business.

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   On record: Based in Los Angeles, California

5. –

   

   Arkansas Business Publishing Group

   Legal

   Arkansas Business Publishing Group publishes business news and reference material for Arkansas.

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6. –

   

   BasicGov Systems, Inc.

   Government · Also in Michigan

   BasicGov Systems, Inc. makes government permitting and licensing software, which its website now presents under the Clariti brand.

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7. –

   

   BitCot

   Mobile App Development · iOS App · E-Commerce Development · Also in United States of America

   BitCot is a software development company in San Diego. It currently focuses on healthcare AI and compliance-minded applications, and it also has a long record of customising…

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   On record: Address in California

8. –

   

   Bydrec Software

   Collaboration · Outsourcing · Also in Pleasanton, California

   Bydrec Software connects technology professionals in Latin America with companies in the United States that need to grow their development teams.

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   On record: Based in California, USA

9. –

   

   California Web Design

   California Web Design builds websites and runs online marketing for small business owners.

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   On record: Based in California, United States

10. –

    

    Clavax

    Mobile App Development · Custom Software Development · Web Development · Also in United States of America

    Clavax is an IT services company headquartered in San Jose, USA, with a presence in Sydney, Australia. It works in digital product engineering for web and mobility.

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    On record: Address in California

11. –

    

    CoreView

    Responsive

    CoreView Systems is a software development firm that takes on the design and build of large-scale software products for client companies.

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    On record: Based in Pune, India and Fremont, California, United States

12. –

    CB

    Creative Blue Media

    Arts, Entertainment & Music · Advertising & Marketing · Business Services

    Creative Blue Media is a San Diego agency that combines website work, brand design and paid digital marketing.

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    On record: Based in San Diego, California, USA

13. –

    CS

    Custom Software Solutions, Inc

    Consumer Products & Services · Advertising & Marketing · Business Services

    Custom Software Solutions, Inc builds bespoke software for businesses from its base in Irvine, California.

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    On record: Based in Irvine, California

14. –

    

    Dibutech

    Financial Services · Information Technology · Automation

    Dibutech is a custom software development company in California that turns business ideas into working, scalable software.

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    On record: Based in Concord, California, US

15. –

    

    Distillery Tech

    Mobile App Development · Custom Software Development · Web Development · Also in United States of America

    Distillery Tech is a software design and development company headquartered in Los Angeles, California.

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    On record: Based in Los Angeles, California, USA

16. –

    

    Ecognition Labs

    Advertising & Marketing · Business Services · Financial Services

    Ecognition Labs is a venture studio in Irvine, California that builds intelligent automation for business clients.

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    On record: Based in Irvine, California

17. –

    

    Epik Systems

    Energy & Natural Resources · Financial Services

    Software development firm building AI, blockchain and edge computing products for startups and established organisations

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    On record: Based in Carlsbad, California

18. –

    

    Excl Networks

    Arts, Entertainment & Music · Energy & Natural Resources · Financial Services

    Excl Networks is a software development company based in San Diego, California. It builds websites and applications for clients who want an online presence and a branded look.

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    On record: Based in San Diego, California

19. –

    

    EZ Digital

    Advertising & Marketing · Business Services · SEO

    EZ Digital is a software and digital design agency based in Los Angeles.

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    On record: Based in Los Angeles, California

20. –

    

    Genesys

    Consumer Products & Services · Energy & Natural Resources · Web Design

    Genesys makes Genesys Cloud CX, a customer experience platform for large organisations.

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    On record: Based in Menlo Park, California, United States

21. –

    

    Graviton Consulting Services

    Cloud

    Graviton Consulting Services is a small professional services firm in Sacramento, California.

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    On record: Based in Sacramento, California, United States

22. –

    

    Hashtag Systems Inc

    Web Development · Web Design · Software Development · Also in United States of America

    Hashtag Systems Inc is a software development and outsourcing company. Its headquarters are in Sunnyvale, California, with further offices in San Diego and Kochi in India.

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    On record: Based in Sunnyvale, California, USA

23. –

    

    Icicle Technologies Inc.

    ERP · Automation · Collaboration · Also in Canada

    Icicle Technologies Inc. makes Icicle ERP, an enterprise system built specifically for food manufacturers. It joins production, inventory and food safety data in a single system.

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24. –

    

    INT9 Solutions

    Software Development · Web Services · IoT · Also in Newark

    INT9 Solutions is a data and cloud consultancy that helps companies turn their data into something they can act on. It lists offices in California and in India.

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    On record: Office in California

25. –

    

    Intrinsyc Technologies Corporation

    IoT · Internet

    Intrinsyc Technologies Corporation is listed with a website that now carries the Lantronix name and branding.

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