Web App Development Firm: Website & Web Application Development Services

Updated September 2026 · Written and maintained by the Progression Agency strategy team

A web application is software people use in a browser — a client portal, a booking system, an internal dashboard, a SaaS platform. Progression Agency is a web app development company that designs and builds custom web applications, progressive web apps and the APIs behind them for businesses across the United States. This page covers what we build, how we build it, which technologies we use and what web application development typically costs.

On this page · 12 sections

What is web application development?
Our web application development services
Web app, progressive web app or native mobile app?
How we build web applications
Performance, accessibility and security
How much does web application development cost?
Why choose Progression Agency to build your web app?
Related services
Website and web app development services
Web application examples by industry
Web app hosting and running costs
Video: web apps and progressive web apps

The short answerWeb application development services cover the planning, design, front-end and backend engineering, hosting and support of browser-based software. A web app runs on every device with a browser, needs no app-store approval, updates instantly for every user and is usually the fastest route to a working product. Progression Agency builds web apps in TypeScript, React and Next.js on Node.js or Python backends with PostgreSQL, hosted in your own cloud account, and can extend the same product to iOS and Android when you need it.

Cost figures are typical US-market planning ranges, not quotes. Browser capability notes reflect MDN and web.dev documentation as of September 2026.

Web applications we build — All five share the same foundations: accounts and permissions, a well-designed data model, integrations and a fast, accessible interface.

What is web application development?

Web application development is the process of designing, building, deploying and maintaining interactive software that runs in a web browser. Unlike a brochure website, a web app has user accounts, stores and processes data, and lets people complete tasks — placing orders, managing projects, booking appointments, analyzing reports.

Because it runs in the browser, a web app works across desktop, tablet and phone without separate builds, and every user gets updates the moment they are deployed. For most businesses it is the fastest and most economical way to put custom software in front of customers and staff.

Portal — Client portals. Self-service accounts, documents, billing..

SaaS — SaaS platforms. Multi-tenant products you sell..

Ops — Internal tools. Dashboards and workflow apps..

Book — Booking systems. Scheduling with payments..

Mkt — Marketplaces. Buyers, sellers and payouts..

PWA — Progressive web apps. Installable, offline-ready..

Our web application development services

Custom web app development

Bespoke applications designed around your workflows, from a focused internal tool to a full customer-facing platform.

Progressive web app development

Progressive web apps can be installed to a home screen, load quickly on poor connections and work offline to a degree, using service workers and a web app manifest as documented on web.dev. They are ideal when you want an app-like experience without app-store distribution.

SaaS platform development

Multi-tenant architecture, subscription billing, roles and permissions, onboarding and admin — see SaaS development.

API and integration development

REST and GraphQL APIs, webhooks and integrations with CRMs, ERPs, payment processors, email platforms and AI models.

Front-end development

Fast, accessible interfaces in React and Next.js, built to WCAG 2.2 AA and tuned for Core Web Vitals.

Web app modernization

Rebuilding ageing applications on current frameworks, module by module, without interrupting the people who depend on them.

Web app vs native mobile app — Most business software starts as a web app because it reaches every device immediately. A mobile app is added when hardware access, offline field use or push-driven engagement justify it.

Web app, progressive web app or native mobile app?

Start with a web app when reach, speed and cost matter most; choose a progressive web app when you also want home-screen installation and offline use; add native mobile apps when you need deep device hardware, background processing or app-store presence.

Comparing delivery options
Option	Strengths	Limits
Web application	Every device, instant updates, no store review	No home-screen presence by default
Progressive web app	Installable, offline-capable, one codebase	Device access narrower than native, especially on iOS
Native / cross-platform app	Full hardware access, push, store discovery	Store review, two platforms to maintain

Many of our clients run both: a web application as the main product and a companion mobile app sharing the same backend.

Anatomy of a modern web application — Each layer is designed deliberately. The data model in particular decides how easy the application is to extend two years from now.

How we build web applications

We design the data model and architecture first, build in two-week sprints with working releases, test automatically on every change and deploy through a CI/CD pipeline into your own cloud account.

3 — Architecture. Stack and data model..

4 — Sprints. Working releases every two weeks..

5 — QA and security. Tests, reviews, checks..

6 — Launch and support. Monitoring and improvements..

Our web application technology stack
Layer	Technologies
Front end	TypeScript, React, Next.js
Backend	Node.js, Python
Data	PostgreSQL, Redis, object storage
APIs	REST, GraphQL, webhooks
Hosting	AWS, Azure, Google Cloud, Vercel
Quality	Automated testing, code review, CI/CD

Fast — Core Web Vitals. Performance budgets from day one..

Accessible — WCAG 2.2 AA. Usable by everyone..

Secure — OWASP-aligned. Auth, roles, encryption..

Scalable — Cloud native. Grows with usage..

Owned — Your accounts. Code and hosting in your name..

Found — SEO-ready. Public pages that rank..

Performance, accessibility and security

We set performance budgets aligned with Google’s Core Web Vitals, build to WCAG 2.2 AA, and follow the OWASP Top 10 for application security: strong authentication, role-based access, encryption in transit and at rest, and audit logging where the data warrants it.

How much does web application development cost?

As a planning range, a focused web app or internal tool commonly costs roughly $25,000-$75,000, a customer-facing portal or platform roughly $75,000-$200,000, and complex SaaS or marketplace platforms more. Hosting and support are ongoing monthly costs.

Web app development cost ranges (planning figures)
Scope	Typical range	Typical timeline
Progressive web app / focused tool	$25,000-$75,000	2-4 months
Client portal	$60,000-$150,000	3-6 months
SaaS MVP	$60,000-$150,000	3-6 months
Marketplace or complex platform	$150,000+	6-9+ months

Search demand for web app developers — These are buying searches: people choosing a partner to build a specific application.

Why choose Progression Agency to build your web app?

One team for strategy, UX, engineering, hosting and launch.
You own the code, data and cloud accounts.
Written scope and estimate before development.
Working releases every two weeks.
Public-facing pages built to rank, with our SEO and AEO teams involved.
Headquartered in New York City, working nationwide.

Website and web app development services

Website app development services combine a public website with the application behind it — accounts, dashboards, booking, payments or a client portal. As a web app development firm we build both halves so the marketing site and the product share one design system, one login and one set of analytics.

Web software development

Web software development covers any software delivered through a browser, from a small internal tool to a multi-tenant SaaS platform. It is usually the fastest way to reach every device at once.

Choosing a website and application development company

Look for a firm that can design and build the website, the web application and the integrations between them, and that will host everything in accounts you own.

Web application examples by industry

Every industry has recurring web app patterns. These are the ones we build most often.

Common web applications by industry
Industry	Typical web applications
Professional services	Client portals, document exchange, intake and billing
Healthcare	Patient portals, scheduling, telehealth dashboards
Real estate	Listing platforms, tenant portals, deal tracking
Retail and ecommerce	Order management, B2B ordering portals, loyalty dashboards
Logistics	Dispatch boards, tracking portals, driver management
Education	Learning platforms, enrolment and progress tracking

Single-page apps, multi-page apps and hybrid rendering

Single-page apps load once and update in place, which suits dashboards and tools; server-rendered pages load fast and are easy for search engines to read, which suits public content. Frameworks such as Next.js combine both, which is why we use them for most projects.

Choosing between REST and GraphQL

REST is simple, cache-friendly and widely understood; GraphQL lets clients request exactly the data they need, which helps apps with many screens and a mobile client. We choose per project and document the reason.

Web app hosting and running costs

Most web apps run on managed cloud services billed by usage. Small internal tools often cost tens to a few hundred dollars a month to host; high-traffic platforms cost more. We model hosting cost during architecture so there are no surprises.

Planning a web application?

Tell us who will use it and what it needs to do. We will recommend an approach and a planning estimate.

Get a web app proposal

Video: web apps and progressive web apps

Chrome for Developers training on progressive web apps, plus a short React explainer.

When should you use a PWA? – Progressive Web App Training
Chrome for Developers · 2019-03-11
Intro & Setup – Progressive Web App Training
Chrome for Developers · 2019-03-06
Kickstarting Your Journey to Progressive Web Apps (Chrome Dev Summit 2017)
Chrome for Developers · 2017-10-23
React in 100 Seconds
Fireship · 2020-09-08

Getting found in search

AI, AEO and what is changing

Paid media and lead generation

Websites and design

Choosing and working with an agency

Software and app development

Social, content and brand

By industry and by situation

Frequently asked questions

What is a web application?

Interactive software that runs in a browser, with user accounts and data, such as a portal, dashboard, booking system or SaaS product.

What is the difference between a website and a web app?

A website mainly presents information; a web app lets users log in, work with data and complete tasks.

How much does it cost to build a web app?

As a planning range, focused web apps commonly cost roughly $25,000-$75,000 and customer-facing platforms roughly $75,000-$200,000, with complex platforms more.

How long does web app development take?

Focused tools often take 2-4 months; portals and SaaS MVPs 3-6 months; complex platforms longer.

What is a progressive web app?

A web app that can be installed to a home screen and work offline to a degree, using service workers and a web app manifest.

Should I build a web app or a mobile app?

Start with a web app for reach, speed and cost; add native apps when you need device hardware, offline field use or store presence.

Which technologies do you use for web apps?

TypeScript, React and Next.js on the front end; Node.js or Python backends; PostgreSQL; hosting on AWS, Azure, Google Cloud or Vercel.

Can a web app work offline?

Yes, to a degree. Progressive web apps cache content and queue actions with service workers.

Is a web app secure?

It can be very secure when built with strong authentication, role-based access, encryption and OWASP-aligned practices, which is our standard.

Can you integrate the web app with our CRM or ERP?

Yes. CRM, ERP, accounting, payment and email integrations are routine for us.

Who hosts the web application?

We recommend hosting in your own cloud account so you control it; we manage it under a support plan if you prefer.

Do web apps need maintenance?

Yes: security patches, dependency updates, monitoring and improvements keep them healthy.

Can a web app rank on Google?

Its public pages can. We server-render public content and structure it for search and AI answers.

Do you build accessible web apps?

Yes. We design and test to WCAG 2.2 AA.

What is a SaaS web application?

A web app sold as a subscription to many customer organizations, usually with multi-tenant architecture.

Can you rebuild our old web application?

Yes, typically incrementally, replacing modules while the existing system keeps running.

Do you provide UX design for web apps?

Yes. We map workflows and test a clickable prototype with users before building.

Can you turn our web app into a mobile app later?

Yes. With a well-designed API, iOS and Android apps can share the same backend.

What are Core Web Vitals?

Google’s metrics for loading, interactivity and visual stability, which we use as performance budgets.

Who owns the code?

You do, contractually, with repositories and accounts in your name.

Do you work with startups?

Yes, usually starting with a focused MVP.

Where is Progression Agency located?

New York City, working with clients across the United States.

Sources and further reading

Need software built?We design, build and support custom software, web apps and SaaS platforms, with a written scope first.

Get a software proposal

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Tell us what you are trying to grow and we will come back with a plan, not a pitch deck. Same-day reply on weekdays.