Software and app development in Fairfax County, Virginia.
Cosmic is a software and app development firm in McLean, in Fairfax County, Virginia, that builds custom production apps and AI features for private companies. A US-based core team of four directs AI coding agents in harnesses we built ourselves and reviews every change before it ships. We don't do government work or hold security clearances.
For private companies. A free 30-minute call first; we’ll meet in person in Northern Virginia.
What we build
Custom production apps, judged by what they do for revenue, margin or time. AI is the core of most of what we ship now; see AI consulting in the Washington DC area.
Custom production apps
Internal tools and customer-facing web apps built to a stated revenue, margin or time goal, shipped in small releases.
AI features inside your product
Agents, search and drafting built into the workflow your team already runs, measured against a baseline.
MVPs in 10 days
One core workflow for one type of user, tested with real users twice and deployed on your accounts.
Vibe-coded apps to production
An app built in Lovable, Replit or Cursor, with its core workflow made ready for real users and a plan for the rest.
A commercial firm in a federal county
Fairfax County’s software market grew up around federal work. That shapes who you’ll find when you search.
Many software firms around Tysons and Reston lead with federal registrations, contract vehicles and cleared staff. That overhead is right for a government program. A private company building a product or an internal tool doesn’t need it and shouldn’t pay for it.
Cosmic works only for private companies: startups, growing firms and fast-moving teams inside large enterprises. We’re headquartered in McLean, so discovery happens in your office and working sessions happen in person when a whiteboard helps.
How AI changes software delivery
As our founder Saad Ahmed puts it: “AI makes code cheap, but also expensive to repair and fix when AI builds bloated features no one uses.”
Faster with agents
Scaffolding, screens, tests, migrations and the first working version of a workflow. Agents write much of it inside harnesses we built for that job.
Still human work
Deciding what to build, the data model, security, integrations with your systems, and reviewing every change an agent makes before it ships.
What it means for you
Working software sooner, in smaller releases, and a team that spends its hours on judgment rather than typing.
Four ways to get software built in Northern Virginia
Figures from the Bureau of Labor Statistics (May 2025, Washington-Arlington-Alexandria metro area) and Clutch’s Washington, DC listings, checked October 2026. The full math is in what it costs to build an app in the Washington DC area.
| Path | Cost signal | Best for | Watch for |
|---|---|---|---|
| Hire in-house | Median software developer pay in the Washington metro area: $154,930 a year (BLS, May 2025), before benefits and recruiting | You need a permanent team and can wait for hiring | Months to hire; you compete with federal contractors for the same people |
| Local development shop | Firms with a real local office on Clutch's DC pages mostly list $100 to $199 an hour | A defined project with a full team | Check where the developers sit and who reviews their work |
| Offshore firm with a local address | Several firms listed on Clutch's DC pages bill $25 to $49 an hour and deliver from overseas | Well-specified work and a budget limit | Time zones, review load and who owns the result |
| Cosmic | Priced per sprint plus an outcome-linked fee tied to one business number, quoted on a short first call | A private company that wants AI and software shipped against a number | A core team of four; we'll say so if you need dozens of engineers |
Choosing between firms? Read how to choose a software or AI firm in Northern Virginia.
Recent custom production apps
Client names stay private; the numbers are from the builds.
Evidence-based talent marketplace
A production stack in six days: 30 database tables, row-level security and about 470 automated tests.
Autonomous agent control plane
23 pull requests merged in one unattended 8-hour run, for $1.42 in model costs.
Agent work coordinator
99 tools that people and AI agents use to plan, claim and close work on one backlog.
Multi-site content engine
Six content sites started on one engine in 45 days.
Frequently asked questions
Is there a software development company in Fairfax County that doesn't do government work?
Yes. Cosmic is in McLean, in Fairfax County, and works only with private companies. We don't work under government contracts, on government systems or data, or on anything that needs a security clearance.
Who writes the code?
Cosmic's US-based core team of four directs AI coding agents that run in harnesses we built ourselves, and a person on the team reviews every change before it ships. The people on your first call are the people who do the work.
Which parts of Northern Virginia do you work in?
All of it. We're in McLean and meet clients in person in Tysons, Reston, Herndon, Fairfax, Vienna, Arlington and Alexandria, and across Washington, DC and the Maryland suburbs. The build itself runs remotely between visits.
How much does custom software cost in Northern Virginia?
It depends on the path. A median software developer in the Washington metro area earns $154,930 a year (BLS, May 2025) before benefits, and local development shops on Clutch mostly list $100 to $199 an hour. Cosmic prices per sprint plus an outcome-linked fee and quotes on a short first call. The full breakdown is in our app development cost guide.
How fast can you build an MVP?
In 10 days for one core workflow for one type of user, tested with real users twice and deployed on your accounts. Larger products ship in further releases after that.
Do you build native mobile apps?
Most of what we build is web apps people use in the browser, which are the fastest to build, ship and change. We'll tell you on the first call if your product needs native mobile work and whether we're the right team for it.
Last updated October 2026