Chicago Metro Service Areas
Where we build software in Illinois
We build custom software for companies all over the Chicago metro.
QOS Software builds custom software — web and mobile apps, enterprise systems, e-commerce, API integrations, and UI/UX — for companies across the eight-county Chicago metro: Cook, DuPage, Lake, Kane, McHenry, Will, Kendall, and Grundy. That covers the city core and the collar counties, from downtown and the Loop out to Naperville, Aurora, Waukegan, and Joliet. Outside those counties? We work statewide and nationwide — just ask.
We’re remote-first, so day-to-day development, design, and project work doesn’t depend on where your office sits. When a project benefits from being in the room — discovery workshops, stakeholder interviews, on-site testing — we come to you across the metro. The map shows the eight counties; the section below covers how we work inside them and at the edges.
In central Indiana instead? See our Central Indiana service areas.
Not sure if we cover you?
Tell us your city or county and we’ll confirm the same business day — no obligation. On the edge of the map? We’ll tell you exactly what building software with us looks like from there.
How our coverage works
Two things decide whether we’re a fit: what you need built and where you are. We build custom software of almost any kind — here’s the honest version of the “where.”
Remote across Illinois. Coding, design, review, and project communication happen online, so distance inside the metro or across Northern Illinois is rarely a barrier.
On-site across the Chicago metro. When a project genuinely benefits from face-to-face work — discovery, mapping an existing workflow, or training your team at handoff — we come to you across Cook and the collar counties.
Just outside the eight counties below? Ask us anyway. The list is where we’re focused in the metro, not a fence — we deliver remotely across Illinois and nationwide, so one county over never rules you out.
Rather just ask us directly?
Tell us where you are and what you're trying to build, and we'll tell you honestly whether we're the right fit — no obligation, no sales pressure.
The 8 counties we serve
Where we're focused across the Chicago metro — one county at a time.
Cook
Chicago, Evanston, Schaumburg, and Arlington Heights — the city core, from downtown and the Loop out to the northwest suburbs.
DuPage
Naperville, Wheaton, Downers Grove, and Bartlett — the western suburbs and the I-88 tech corridor.
Lake
Waukegan, Gurnee, Mundelein, and Buffalo Grove — the North Shore up to the Wisconsin line.
Kane
Aurora, Elgin, St. Charles, and Carpentersville — the Fox Valley and the western river cities.
McHenry
Crystal Lake, McHenry, Woodstock, and Algonquin — the northwest metro along the Fox River.
Will
Joliet, Bolingbrook, Plainfield, and Romeoville — the southwest metro and the I-55 logistics corridor.
Kendall
Oswego, Yorkville, and Montgomery — our southwest edge: remote-first by default, on-site as the project needs.
Grundy
Morris, Coal City, and Minooka — our outer southwest edge: remote-first delivery, on-site visits as the work requires.
What we build for Illinois businesses
Coverage is only half the question — here’s what we actually build. Every engagement is custom, scoped to your business, and handed over as software you own.
- Web application development — browser-based apps, portals, dashboards, and SaaS platforms.
- Mobile app development — iOS, Android, and cross-platform apps.
- Enterprise software development — back-end systems, databases, and legacy modernization.
- E-commerce development — custom online stores and checkout experiences.
- UI/UX design — research, wireframes, and interface design.
- API integrations — connecting the systems and third-party tools you already run.
Service Area Questions
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Do you work remotely or on-site?
Both. Most of our custom software development — coding, design, project management, and reviews — happens remotely, so we work with clients across the Chicago metro and nationwide. When a project benefits from in-person work, like discovery workshops or team training, we come on-site across Cook and the collar counties.
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What if my business is outside the counties you list?
You can still work with us. The counties we list are where we're most focused in the Chicago metro, not a hard boundary. We deliver remotely across Illinois and nationwide, so being just outside the list doesn't rule you out — tell us where you are and we'll confirm.
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Do you serve clients outside the Chicago metro?
Yes. Our home base is Central Indiana and the Chicago metro is our growing second market, but our remote-first delivery lets us build custom software for clients anywhere in the United States. Where you are rarely changes how a software project is scoped or delivered.
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Do you only build custom software, or also IT support?
We build custom software only — web and mobile apps, enterprise systems, e-commerce, and integrations. Managed IT and help-desk support are handled by our sister company, QOS MSP (qosmsp.com), and AI agents or automation by QOS Agentic (qosagentic.com). If you need one of those, we'll point you to the right team.
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Do I need to visit your office to start a project?
No. You can start entirely remotely — discovery calls, scoping, and project updates all happen online. If you'd prefer to meet in person and you're in the Chicago area, we're happy to, but it's never required to work with us.