US-based custom software development company building 300+ products for startups with AI, mobile, web, and SaaS expertise.
Rising Star10+ YearsLarge Team
Custom Software DevelopmentTop 10 Elite
The very best agencies • View detailed Top 10
Agencies 11–25
Strong contenders and rising stars
360 Degree Cloud is a Salesforce Summit Partner and cloud consulting firm delivering end-to-end Salesforce CRM, AI-driven transformation, integration, implementation, and managed services globally.
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Software development with 20+ years experience delivering custom software, AI solutions, cloud services, and data engineering.
Rising StarAWS PartnerMicrosoft Partner+2 more
Custom Software Development
Growth engine for enterprises and startups solving software problems with AI, mobile apps, and customer-centric approach.
Rising Star10+ YearsMid-Size
Custom Software Development
Blockchain and software development company offering DevOps services with focus on platform extensibility and application delivery automation.
10+ YearsMid-Size
DevOps & CI/CDAI/ML Development
Cloud DevOps consulting firm specializing in healthcare and biotechnology applications with expertise in AWS, Azure, and hybrid cloud environments.
10+ YearsSmall Team
DevOps & CI/CDCustom Software Development
Innovative IT Solutions Driving Business Success Worldwide
15+ YearsLarge Team
Product Engineering (SaaS)AI/ML Development
IT consulting and software development firm near San Francisco offering MVP development with IoT and AI expertise.
15+ YearsLarge Team
Custom Software Development
Software development and DevOps consulting company providing comprehensive solutions for automation, deployment, and infrastructure management.
15+ YearsSmall Team
DevOps & CI/CDCustom Software Development
Global technology services firm providing comprehensive QA and test automation services with focus on digital transformation.
15+ YearsEnterprise
Custom Software Development
Enterprise AI and product engineering firm specializing in DevOps automation, CI/CD pipelines, cloud migration, and infrastructure as code solutions.
15+ YearsLarge Team
DevOps & CI/CDCloud Migration & Modernization
Software engineering partner offering end-to-end engineering services from legacy and cloud-migration to AI/ML and data solutions.
Google PartnerAWS PartnerMicrosoft Partner+2 more
Custom Software Development
Remote-first DevOps consultancy providing infrastructure automation, CI/CD services, and cloud-native solutions across US, Canada, and Latin America.
10+ YearsBoutique
DevOps & CI/CDCustom Software Development
Custom CRM development company providing implementation services for Salesforce, HubSpot, and custom solutions.
15+ YearsMid-Size
Custom Software DevelopmentData Engineering & Modern Data Stack
Leading DevOps platform company specializing in continuous integration, continuous delivery, and software development acceleration.
15+ YearsEnterprise
DevOps & CI/CDCloud Migration & ModernizationComplete Top 25 Custom Software Development Agencies in California
Full numbered list of all 25 agencies
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Complete Top 25 Custom Software Development Agencies in California
Full numbered list of all 25 agencies
- 1.EPAM Systems — Pennsylvania
- 2.Stateside Agency — California
- 3.BairesDev — California
- 4.Azumo — California
- 5.Intellectsoft — California
- 6.Gearheart — California
- 7.CodeBright — California
- 8.Cheesecake Labs — California
- 9.WinWire Technologies — California
- 10.eSparkBiz — California
- 11.LITSLINK — California
- 12.360 Degree Cloud — California
- 13.Zerone Consulting — California
- 14.OyeLabs — California
- 15.HashCash Consultants — California
- 16.TATEEDA Global — California
- 17.A3logics — California
- 18.Altoros — California
- 19.AppStudio — California
- 20.Aspire Systems — Illinois
- 21.Azilen Technologies — California
- 22.Binariks — California
- 23.Bluelight Consulting — California
- 24.Closeloop Technologies — California
- 25.CloudBees — California
Top 25 Custom Software Development Agencies — FAQ
Common questions about the best custom software development agencies in California.
Who is the #1 custom software development agency in California in 2026?
As of 2026, the top-ranked custom software development agency in California on AgencyCluster is EPAM Systems, with an AgencyCluster Score of 100/100. Rankings are based on verified evidence across credibility, proof of work, reputation, category specialization, delivery maturity, and freshness. Rankings are updated periodically as new evidence becomes available.
How were the top 25 custom software development agencies in California selected?
This list features 25 agencies selected from AgencyCluster's curated directory. Each agency was evaluated using the AgencyCluster Score (0–100), with particular weight on demonstrated expertise in custom software development. Only agencies with verified credentials are eligible, and rankings cannot be purchased. The agencies on this list average 17+ years of experience. For full methodology details, see our How We Rank page.
What should I look for when choosing a custom software development agency from this list?
Prioritize agencies that lead with a discovery phase before quoting. Ask how they handle requirements changes mid-project. Request references from clients with similar complexity (not just similar industry). Check if they provide architecture documentation and whether they've built systems that have scaled in production.
How much do the top custom software development agencies typically charge?
Custom enterprise software projects typically range from $100K–$1M+. Smaller internal tools or integrations may start at $50K. Post-launch support and iteration usually costs $10K–$40K/month.
Trusted Rankings
Every agency on this list has been reviewed by our editorial team. Rankings are based on our transparent methodology which evaluates credibility, outcomes, and reputation.
No paid rankingsVerified credentialsUpdated regularly
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