TOP 10 LIST•2026

Top 10 Custom Software Development Agencies in Illinois (2026)

The best custom software development agencies in Illinois, curated by AgencyCluster.

8 verified agencies
20+ years avg. experience
Updated today

The Top 10

The absolute best in custom software development

Dean Infotech
#1Dean Infotech
Illinois·Mid-Size·18+ yrs·Score: 100

Top Certified HubSpot and Salesforce Partner with 15+ years experience serving 300+ clients with 200+ successful projects.

Top Rated15+ YearsMid-Size
Custom Software Development
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ELEKS
#2ELEKS
Illinois·Large Team·35+ yrs·Score: 100

Global technology partner with 30+ years experience delivering custom software and mobile solutions for enterprises across industries.

Top Rated15+ YearsLarge Team
Mobile App DevelopmentCustom Software Development
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SCALO
#3SCALO
Illinois·Large Team·19+ yrs·Score: 100

Custom software and IT talent solutions with 20 years excellence, 750+ projects, ISO 27001 certified, Microsoft Gold Partner.

Top Rated15+ YearsLarge Team
Custom Software Development
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Espeo Software
#4Espeo Software
Illinois·Small Team·18+ yrs·Score: 61

Agile software development company building accessible DevOps solutions that solve continuous delivery complications and integrate with existing tools.

Rising Star15+ YearsSmall Team
Custom Software DevelopmentProduct Engineering (SaaS)
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Chetu
#5Chetu
Florida·Enterprise·26+ yrs

Empowering Business Innovation through Custom AI and Digital Transformation Solutions

15+ YearsEnterprise
AI/ML DevelopmentCloud Migration & Modernization
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Vega IT
#7Vega IT
Illinois·Mid-Size·18+ yrs

Staff augmentation company specializing in custom software development supporting web and mobile application development across industries.

15+ YearsMid-Size
Staff Augmentation / Dedicated TeamsCustom Software Development
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Xcelacore
#8Xcelacore
Illinois·Boutique·12+ yrs

IT staff augmentation and software development company providing rapid team scaling with flexible engagement models for startups and enterprises.

10+ YearsBoutique
Custom Software Development
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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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