quadevs

Software development company for stores, B2B platforms and AI agents.

Custom software development for companies in the United States, the United Kingdom and Europe: online stores, B2B platforms, websites for small and service businesses, mobile apps, AI agents and healthcare systems. Hire software developers by the project, by the hour or as a team.

Independent software studio since 2016. You speak directly with the engineers who write the code.

demo › Illustrative events · not a live feed

Engineering and growth services.

Engineering covers the software we build and keep running; growth covers search, AI answers and ads for the sites we build or take over.

Healthcare software development

Interoperability, quality reporting, clinical data and document pipelines: our largest group of cases.

  • Clinic websites
  • Appointment booking
  • EHR, lab and API integration
  • TEFCA and FHIR
  • HEDIS reporting
  • Clinical data platforms
  • Medical document OCR
  • Patient mobile apps
  • Medical
  • and much more

AI agent development

Agents that act inside your systems and log every tool call they make.

Custom AI model development and training

A model for one repeated decision, with uncertain cases routed to a person.

.NET development and consulting

.NET systems built to run for years, and older ones moved to current .NET.

React development company

React and Next.js front ends for platforms and internal tools.

Python development services

Python back ends that one operations person can keep running.

Node.js development services

Node.js and Express behind courses, subscriptions and booking flows.

Web development company for custom web applications

Custom web applications for work that packaged software handles badly.

Mobile app development for iOS and Android

Mobile apps from the first build to the next store update.

  • Patient mobile apps
  • and much more

Windows desktop application development

Desktop software for people who work in one application all day.

API development, web services and Windows services

The APIs and background services your other systems call every day.

Legacy application modernization

Software from the 1990s and 2000s brought onto current technology.

Software maintenance and application support

An owner for software already in production, ours or another team's.

Shopify development agency

Apps and storefronts that merchants run without an agency.

WordPress development and support

WordPress sites that editors update themselves, with hosting under contract.

SEO services and technical SEO

SEO services that end with the fixes deployed and checked.

  • Local
  • E-commerce
  • SaaS
  • International
  • Migration
  • Medical
  • and much more

Generative engine optimization (GEO)

How ChatGPT, Perplexity and Google AI answers describe your business.

Social media scheduling and content production

The publishing system behind a brand that posts every day.

Targeted advertising, PPC and conversion tracking

Targeted ads with conversion data your PPC team can reconcile with sales.

Selected work: online stores, platforms, AI agents and healthcare.

Most of these projects are under NDA, so each case describes the system and its result without the client name. We share names on a call.

A typed schema for conversion events.

This example describes the fields a conversion event can carry: event type, value, attribution and page path.

The schema defines the event format. Consent handling, personal-data checks, delivery and audit logging need to be implemented separately.

From first call to a system you can audit.

  1. Estimate and plan

    A small change can be estimated within an hour; a large system takes longer to map. The written plan and estimate come before any work starts.

  2. Build and weekly demos

    A demo of working software every week, running on a staging copy of your production setup.

  3. Cutover and live week

    Monitoring, runbooks and on-call cover through the switch; we count the work as done after a week of live traffic.

  4. Ongoing ownership

    Monthly support hours, or a handover with runbooks, dashboards and recorded walkthroughs.

How we engage, phase by phase

Tell us what you are trying to ship.

A store or a mobile app, an LLM agent, an internal platform nobody maintains any more, or a healthcare integration. Outsource software development to us end to end, or add our engineers to your team.

A short brief gets a real reply within one business day.

Budget range (optional)

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Or email hello@quadevs.com.

Technologies we ship to production

Next.js
React
TypeScript
Node.js
Python
.NET
PHP
PostgreSQL
Microsoft SQL Server
Redis
Elasticsearch
Stripe
Shopify
WordPress
Twilio
Amazon Web Services
New Relic
Swift
Kotlin
GitHub
Express
Vite
Mapbox
Cloudflare
Docker
Nginx
Sentry
WebRTC
Three.js
Tailwind CSS
Supabase
GraphQL
and many more

Plus FHIR R4, SMART-on-FHIR, HL7, OAuth2, WebSocket, GPU workers, OpenCV, LeadTools, and whatever else your stack runs on. Tell us what you run.