Top Custom Software Development Companies in St. Louis, MO
We ranked 9 custom software development companies in and around St. Louis, MO on client reviews, how many are verified, service focus and profile completeness. Includes companies in nearby Collinsville, IL. Updated October 2026. How rankings work
Partners that build software around how a business actually works, often replacing spreadsheets and a patchwork of subscriptions with one system the company owns.
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Custom software firm in Collinsville, Illinois, near St. Louis, building web and mobile apps, ERP and integrations, and business process automation.
No reviews yet
Collinsville, IL
- Custom Software Development
- Mobile App Development
- Web Development
St. Louis custom software studio building inventory, point-of-sale and messaging systems and integrations for businesses that outgrew off-the-shelf tools.
No reviews yet
St. Louis, MO
- Custom Software Development
- API & Integration Development
- Web Development
St. Louis software company that designs and builds custom web applications and DNN sites, and sells association and league management software.
No reviews yet
St. Louis, MO
- Custom Software Development
- Web Development
- UX/UI Design
St. Louis engineering consultancy that designs, modernizes and connects mission-critical software, data and AI systems for high-stakes industries.
No reviews yet
St. Louis, MO
- Custom Software Development
- AI & Automation
- API & Integration Development
St. Louis consultancy that embeds senior U.S. developers to build AI-enabled custom software, with cloud cost management and Atlassian services.
No reviews yet
St. Louis, MO
- Custom Software Development
- AI & Automation
- Managed IT Services
St. Louis product team that designs and builds custom software platforms for professional services firms, from strategic framing to launch and support.
No reviews yet
St. Louis, MO
- Product Design & Development
- Custom Software Development
- API & Integration Development
- Projects from
- $15,000+
St. Louis Microsoft Solutions Partner building custom and AI applications on Azure, alongside data, cloud, HPC, Microsoft 365 and managed services.
No reviews yet
St. Louis, MO
- Custom Software Development
- Managed IT Services
- AI & Automation
St. Louis software studio that researches, designs and builds custom web and mobile apps, e-commerce sites and integrations for SMBs, startups and agencies.
No reviews yet
St. Louis, MO
- Custom Software Development
- Web Development
- Mobile App Development
St. Louis studio that designs, develops and supports websites, web apps and brands, plus accessibility audits, digital strategy and hosting.
No reviews yet
St. Louis, MO
- Web Development
- UX/UI Design
- Custom Software Development
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