Custom Software Development & Penetration Testing in Jacksonville, FL

QUANT LAB USA delivers both, from a Macon, Georgia HQ that shares Jacksonville's Eastern Time zone and sits a straight shot up I-10 and I-75. We serve Jacksonville remote-first, with travel into Duval, St. Johns, and Clay counties for major builds and on-site network work. Our clients there typically need the same things: logistics dashboards that unify legacy systems, Stripe-grade billing, pen test reports that survive procurement, and a single accountable engineer who picks up the phone.

Jacksonville's economy is built on movement and money. JAXPORT is one of the busiest container and vehicle ports in the southeast, and the rail-and-trucking complex around it — served by CSX, which is headquartered downtown — generates constant demand for dispatch, freight-tracking, and warehouse inventory software. The finance corridor is just as deep: FIS anchors a fintech base, and the city is one of the largest insurance employment centers in the country, with carriers and broker operations across the Southside and downtown. Layer in the Baptist Health, Mayo Clinic, and UF Health systems, plus a large Navy presence at Naval Air Station Jacksonville and Mayport, and you have a metro with broad, sophisticated software needs.

Most Jacksonville shops are either large enterprise integrators or solo freelancers. We sit in the middle: founder-led delivery with enterprise-grade engineering practices and in-house offensive security. No offshore handoff and no junior outsourcing — William Beltz scopes, builds, and ships. That matters when a logistics operator needs a real-time dashboard that does not buckle at scale, or when an insurer needs both a custom claims platform and a pen test report that maps to their compliance obligations.

Jacksonville buyers want senior accountability without consultancy overhead. Our model delivers exactly that: every engagement is scoped, built, and shipped by the founder, on a fixed-scope and fixed-price proposal with a written acceptance milestone — not open-ended time-and-materials billing. Our pen testing is in-house capability, not a subcontracted line item: Active Directory abuse paths, lateral movement, ADCS certificate abuse, Kerberoasting, wireless attacks, and web application exploitation, with every finding mapped to a MITRE ATT&CK technique ID. And every line of software we ship is reviewed against the same threat models we use on offensive engagements.

We run full Eastern Time overlap from Macon, which keeps standups and reviews on Jacksonville's clock. Most kickoffs are a video call followed by a single on-site afternoon — typically downtown, on the Southside, or near the beaches — to walk the workflow we are replacing. From there, build cycles run weekly: every Friday you get a deployed staging URL, written notes on what changed, and the next-week plan. Pen testing engagements run from secure remote infrastructure with strict source-IP allowlisting and authenticated VPN tunnels for internal scope, and we travel to Jacksonville for sensitive scoping and for internal tests requiring on-site network access. Reports ship in two formats: a technical deliverable with reproduction steps for the security team, and a board-readable executive summary with a prioritized remediation roadmap. Most Jacksonville engagements close inside 4–6 weeks from kickoff to final report.