Our expert analysts have ranked the best eCommerce development companies in California that build intuitive online stores to help you turn visitors into paying customers. Filter them by portfolios, budget, client reviews, industry reputation and more to find the right fit for your brand.
Best California eCommerce Development Agency Rankings
4 Companies-Rankings updated: September 05, 2026
Every agency on DesignRush meets evaluation criteria around expertise and client feedback to empower informed choices. Some listings include paid partnerships.
VerifiedVerified by the DesignRush team for authenticity and credibility.
Your trusted AI software development partner
Diffco builds Magento and Shopify web stores for retail and eCommerce clients, including grocery delivery platform Food Rocket, from its Silicon Valley base. The 2008-founded eCommerce company also specializes in AI and custom software development, having delivered 1,150+ projects overall...
Top Services:
AI Development
Software Development
Staff Augmentation
Mobile App Development
Web Development
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Location
San Jose, California
Number of Employees
50 - 99
Average Hourly Rate
$110/hr
Minimal Budget
$25,000 - $50,000
Portfolios Count
31 Projects Listed
Diffco Services
AI Development
Software Development
Staff Augmentation
Mobile App Development
Web Development
eCommerce Development
IoT
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
Mars
Food Rocket
FlashGrid
Nokia
Instreamatic
Quire
Legionfarm
Latoken
Genius One
Shift
Data sourced from the agency's DesignRush profile
Diffco Reviews & Testimonials
Oleg Sotnikov
CEO at AppMaster
5.0★
AI Development Review from Oleg Sotnikov
Diffco built a complex, production-grade AI agentic system and backend for our client's fintech platform owning architecture, AI/ML components, and AI agents in a security- and compliance-sensitive environment. They delivered on time and within budget, communicated proactively, and operated like part of our own team, taking ownership and suggesting better solutions throughout. Deep AI/ML and senior backend expertise. We'd happily work with them again.
Julia Platova
VP Strategic Partnerships at OVA Solutions
5.0★
Mobile App Development Review from Julia Platova
We partnered with Diffco for a comprehensive software development project aimed at delivering a mobile application and backend system for our client.
The goal was to create a seamless, secure, and scalable solution within a 4-month timeline and $50k-$200k budget.
Diffcos team was highly professional from start to finish. They handled everything: UI/UX design, backend architecture, API integration, and deployment.
After the launch, they continued to support us with maintenance and performance optimization.
The application received positive feedback and has proven stable and scalable.
Were highly satisfied with Diffcos expertise, commitment, and ability to deliver real results.
Max Shmatkov
Manager at Centerligh
5.0★
Mobile App Development Review from Max Shmatkov
As an advantage of working with this company I’d like to note that their Agile development method is amazing! Diffco earned my trust through such approach and the team’s professional attitude.
Reviews verified by DesignRush and sourced from the agency's profile
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Simform is a premier digital engineering company specializing in Product Engineering, Cloud, Data, Agentic AI, and Enterprise Platform Innovation. We help enterprises and high-growth ISVs build digital experiences and scalable, enterprise-grade products what work at scale...
Top Services:
Software Development
Cloud Consulting
AI Development
Big Data Analytics
DevOps Consulting
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Location
Los Angeles, California
Number of Employees
1000 & Up
Average Hourly Rate
$30/hr
Minimal Budget
$25,000 - $50,000
Portfolios Count
8 Projects Listed
Simform Services
Software Development
Cloud Consulting
AI Development
Big Data Analytics
DevOps Consulting
IoT
eCommerce Development
UI/UX Design
IT Services
Managed Services
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts
Sony Music (EMI)
Pepsico
Zep Inc
Intralinks
Nxt-ID
FreeWire Inc
Accent Inc
Mission Rabies
DoggyBnB
Drizzle Labs
Data sourced from the agency's DesignRush profile
Simform Reviews & Testimonials
Andrew Muroff
CEO at Strainprint Technologies Ltd.
5.0★
Software Development Review from Andrew Muroff
We worked with Simform for many years ongoing software development on our core product, the Strainprint mobile outcomes tracker for medical cannabis patients. We have only positive things to say about their work product and attention to detail. We highly recommend them and will work with them again.
Robel Yemane
Head of Engineering at Privilee
5.0★
Software Development Review from Robel Yemane
I've been working with Simform for over six months now. The engagement began with bringing our subscription management platform in-house, and we've since expanded the partnership to other projects due to their broad skill set and consistent reliability. They've gone the extra mileeven over weekends and public holidaysto help us move faster when needed. Communication and project management have been excellent, with any issues swiftly addressed. It genuinely felt like Simform was invested in our success. Having worked with similar firms throughout my career, I can confidently say Simform stands out and comes highly recommended.
Russ Makhauri
Front-End Engineer at Midas
5.0★
Software Development Review from Russ Makhauri
We worked with Simform to hire a front-end engineer for our SaaS platform. The process was well-organized, and their team was professional, responsive, and efficient. They quickly identified a candidate who met our technical requirements and ensured a smooth onboarding process.
Simforms communication and project management were strong throughout the engagement. They were proactive in addressing feedback and remained flexible in adapting to our needs. While there is some room for improvement in developer vetting and quality assurance, their overall service was excellent.
For companies looking to scale their development teams efficiently, Simform is a reliable partner. Their structured approach, responsiveness, and commitment to client satisfaction make them a great choice. We would recommend them without hesitation.
Reviews verified by DesignRush and sourced from the agency's profile
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Aiming to enhance the lives of billions of users with innovative technology solutions.
BestPeers is a top software development company specializing in custom software, website development, UX/UI design, and full-stack solutions. With a focus on quality, innovation, and timely delivery, BestPeers creates consumer-centric tech solutions across diverse industries, ensuring client satisfaction and...
Top Services:
Digital Strategy
Web Design
eCommerce Development
Web Development
UI/UX Design
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Location
California City, California
Number of Employees
250 - 499
Average Hourly Rate
$25/hr
Minimal Budget
$25,000 - $50,000
Best Peers Services
Digital Strategy
Web Design
eCommerce Development
Web Development
UI/UX Design
WordPress Website Design
Data sourced from the agency's DesignRush profile, its website, and other relevant accounts