Our expert analysts ranked the top product design companies in California that create multiple product categories such as apps, digital platforms, physical products and more to help your brand stand out and engage new audiences. Filter by price, reviews, portfolios and more to select a partner that best fits your business needs.
Organic rankings are determined by five factors: top services, reviews, portfolio, awards/press, and team expertise. Sponsored listings pay for a placement that appears above organic positions. Sponsorship does not affect star ratings or review content - read more on our methodology page.
Your trusted AI software development partner
Diffco is a San Francisco AI-first software engineering partner for growth-oriented teams. We embed senior engineers and product strategists who turn AI vision into shipped, revenue-driving products. Our team has spent the last 18 years building: SaaS platforms, web & mobile apps, and AI products...
Top Services:
- AI Development
- Software Development
- Staff Augmentation
- Mobile App Development
- Web Development
- Show more
- 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
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsDiffco Services
Data sourced from the agency's DesignRush profileMars Food Rocket FlashGrid Nokia Instreamatic Quire Legionfarm Latoken Genius One Shift
Diffco Reviews & Testimonials

AI Development Review from Ivan Pasichnyk
We brought Diffco in to deliver the AI and computer vision components for one of our clients, an image generation startup. Because the work sat inside our own client relationship, we needed a partner we could trust to operate at our standard without us managing them day to day - and that is exactly what we got. Diffco owned the technical approach, built the computer vision and AI layer, and delivered the full scope in three months, on schedule. The engineering quality was high, they raised the right questions early instead of late, and they handled the confidentiality the project required without us having to chase it. After delivery they stayed on to support the system, which mattered to us as much as the build itself. When you subcontract a technical project inside your own client relationship, the risk is that the partner makes you look bad. Diffco did the opposite. They've earned our trust and we'd work with them again.

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.

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.
Reviews verified by DesignRush and sourced from the agency's profile View All ReviewsYour Trusted Partner in Software Development, Product Design and QA
inVerita is a global software, AI, and data engineering company with 150+ engineers across Europe, the USA, and Latin America(Colombia). We build secure, scalable solutions for healthcare, fintech, logistics, retail, defense, and e-learning...
Top Services:
- Software Development
- Big Data Analytics
- AI Development
- Product Design
- Software Testing
- Show more
- Location
- San Francisco, California
- Number of Employees
- 100 - 249
- Portfolios Count
- 16 Projects Listed
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsinVerita Services
Data sourced from the agency's DesignRush profileINTELLIBOARD DOKTOR 24 PATRIOT PERFORCE METHODICS MEDIASHOUT KROGER GROUP HILTI DILLIGENT WGSN
Don't Settle for Average. Work With the Best!
Smart IT offers core IT development services and forms dedicated software engineering teams for long-term projects. Our talent has a rich background in competitive programming and gives us an edge when it comes to thinking outside the box. We guarantee 5 hrs of timezone overlap, regardless of your location...
Top Services:
- Software Development
- Mobile App Development
- Product Design
- AI Development
- Show more
- Location
- San Francisco, California
- Number of Employees
- 50 - 99
- Minimal Budget
- $50,000 & Up
- Portfolios Count
- 6 Projects Listed
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsSmart IT Services
Data sourced from the agency's DesignRush profileMDBerry Persona.ly Zaman Broker Finitera MEDvidi VTB Bank Thinfactory WowWee Classictic My Trusted Builder
Smart IT Reviews & Testimonials

Healthcare Review from Julia Guzman
Smart IT is definitely a team you can trust! We hired Smart IT to develop a hybrid software platform for customer relationships and electronic health record systems. Also, together we launched our mobile apps. The guys have many successful cases behind them in our field and great experience in launching Healthtech products. Their development team implemented all account management-related features for our platform. Now we have the ability to rapidly scale when we need to.
Reviews verified by DesignRush and sourced from the agency's profile View All ReviewsTop Healthcare Product, Technology, & Venture Design Firm
Sidebench is the top healthcare technology design and software engineering firm in the US. We combine strategy, design, technical architecture at every point of our process. We are known for delivering extraordinary business results...
Top Services:
- Mobile App Development
- Software Development
- AI Development
- Wearables
- UI/UX Design
- Show more
- Location
- Los Angeles, California
- Number of Employees
- Under 49
- Minimal Budget
- $50,000 & Up
- Portfolios Count
- 11 Projects Listed
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsSidebench Services
Data sourced from the agency's DesignRush profileAmerican Heart Association Children's Hospital Los Angeles (CHLA) Hoag Hospital Cortica A16Z (Andreessen Horowitz) Lightspeed Venture Partners Microsoft Rud Bull HP Sony
Sidebench Reviews & Testimonials

Translation Services Review from Abhit
They provide consulting services for a healthcare service provider. Sidebench contributed their expertise to a comprehensive mobile application to make sure it would pass Apple Store requirements. Thanks to Sidebench`s input, the application launched on the Apple Store after the first submission. Sidebench`s response times were quick, and they were willing to accommodate a unique working arrangement. The relationship that we had was probably unique; most companies would push to do the development themselves. We only needed Sidebench`s know-how, and they were willing to accommodate us.
Reviews verified by DesignRush and sourced from the agency's profile View All ReviewsCreating Long Lasting Value For Your Business
Digital Solutions is a full-service UI | UX, Website Development, and Application Development Agency located in Irvine, California...
Top Services:
- Design Services
- Web Design
- Product Design
- Web Development
- WordPress Website Design
- Show more
- Location
- Irvine, California
- Number of Employees
- Under 49
- Average Hourly Rate
- $150/hr
- Minimal Budget
- $25,000 - $50,000
- Portfolios Count
- 8 Projects Listed
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsDigital Solutions Services
Data sourced from the agency's DesignRush profileSmartProp Trader dot.LA Founders' Guide FACT Global WeCamped Rello
Product and Webflow design agency for startups & enterprises.
Alien is your trusted partner for elevating your digital presence. From UI/UX design to branding and digital marketing, we empower incubators, startups, and SMEs to thrive in the digital landscape...
Top Services:
- Web Design
- Product Design
- UI/UX Design
- Branding
- Design Services
- Show more
- Location
- Ontario, California
- Number of Employees
- Under 49
- Minimal Budget
- $1,000 - $10,000
- Portfolios Count
- 4 Projects Listed
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsThe Alien Services
Data sourced from the agency's DesignRush profileHDFC Aditya Birla TVS CavinKare IIFL Synergy Zifo Stockal Bizingo Card91
The Alien Reviews & Testimonials

Mobile App Development Review from Kavin Dot
Working closely with The Alien on the redesign of Stockal- global investing platform has been a transformative journey. The collaboration focused on enhancing user experience (UX) through thoughtful UX/UI design, web design, and responsive design. The Alien's expertise has played a pivotal role in shaping Stockal's interface into a streamlined and user-friendly platform for investors from India and the Middle East looking to engage with US stocks.
Reviews verified by DesignRush and sourced from the agency's profile View All ReviewsInteractive presentations, brand, and product design
Bridger is a product, brand, and interactive design studio. We build interactive sales presentations that live at a link and report back who read what. We also design software products so the interface is on brand and easy to use. One senior team, never a template...
Top Services:
- Product Design
- UI/UX Design
- Web Design
- Branding
- Creative Services
- Show more
- Location
- San Diego, California
- Number of Employees
- Under 49
- Average Hourly Rate
- $160/hr
- Minimal Budget
- $1,000 - $10,000
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsBridger Creative Services
Data sourced from the agency's DesignRush profileIBM Oracle City American Express McKinsey & Company Manulife Atlassian Sunrun Seismic Expedia
Amplifying Human Potential
We create global impact through high-quality digital solutions. Were purposefully shaping the digital future across a range of industries. Discover some of our specific industry services...
Top Services:
- AI Development
- Product Design
- Location
- San Francisco, California
- Number of Employees
- 1000 & Up
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsQubika Services
Data sourced from the agency's DesignRush profileIDB Google Nest
Your Partner For Innovation
MTechZilla is a custom software development company helping growing companies and product teams across the US and EU to build software products or scale engineering capacity. Senior, pre-vetted developers fully aligned to your timezone. AWS Partner with 40+ products delivered...
Top Services:
- Software Development
- Mobile App Development
- Web Development
- AI Development
- Cloud Consulting
- Show more
- Location
- San Jose, California
- Number of Employees
- Under 49
- Average Hourly Rate
- $25/hr
- Minimal Budget
- $25,000 - $50,000
Data sourced from the agency's DesignRush profile, its website, and other relevant accountsMTechZilla Services
Data sourced from the agency's DesignRush profileReloShare Sintio Pinnacle Furnished Suites
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