Web Application Development | POLPROG Skip to content

Web Application Development

Modern, performant web applications built with TypeScript, PHP and proven frameworks. From SPAs to full-stack platforms, optimised for speed and SEO.

What We Do

Fast, accessible web applications that users love

The web is the most accessible platform on earth. A well-built web application reaches every device, every operating system, every user without app store gatekeepers. We build web apps that load fast, rank well and convert visitors into customers.

We deliver production-grade web applications with client-side routing, internationalisation, Service Worker caching, structured data and Lighthouse CI checks enforcing high standards across performance, accessibility, best practices and SEO.

Whether you need a lightweight marketing site, a complex internal tool or a full SaaS platform, we architect for performance from day one. Modern CSS, lazy-loaded assets, edge caching and progressive enhancement are foundations, not afterthoughts.

Web Application Development

Production-grade web applications with Lighthouse scores consistently above 90 across performance, accessibility and SEO. Every project receives the same attention to quality and detail.

Proven web delivery track record

When to choose a web application

You want maximum reach without app store dependencies

SEO and organic reach are important to your business

Your users need instant access from any device

You're building an internal tool, dashboard or SaaS product

22
Languages supported
29+
Projects delivered
PWA
Progressive Web App
How we work

Our delivery process

  1. Planning

    Sitemap, wireframes, performance budget

  2. Design

    Responsive UI, design system, accessibility

  3. Build

    Component-driven development, testing

  4. Optimise & Ship

    Core Web Vitals, CDN, monitoring

Technology

Tech stack we use

TypeScript
React
PHP
HTML5 / CSS3
Service Workers
Webpack
Lighthouse
SEO
REST API
i18n
Questions

Frequently asked questions

What kind of web apps do you build?

Everything from lightweight marketing sites to complex SaaS platforms, admin dashboards and internal tools. Each project gets a tailored architecture.

Will my web app work offline?

If needed, yes. We implement Service Workers and progressive enhancement so your app remains functional even without connectivity.

How do you ensure performance?

Performance is a first-class concern from day one. We set Lighthouse budgets, optimise Core Web Vitals and monitor real-user metrics post-launch.

Can you handle multilingual sites?

Yes. We have extensive i18n experience across 22+ languages, including RTL support. This very website supports that many languages.

Portfolio

Example Completed Projects

native-ui.com - the official site for the Native-UI design system
Native-UI icon

Native-UI

Website
v1.0.0

The official home of the Native-UI design system - docs, components, and changelog.

Next.js React TypeScript Tailwind CSS Docker
SDK Documentation Component Catalogue Theming Guide
anna-skrzynska.pl - Anna Skrzyńska portfolio
Anna Skrzynska icon
v1.0.0

Portfolio of visual designer Anna Skrzyńska - brand identity, web design, photography, painting, and interior concepts.

HTML CSS JavaScript
Visual Portfolio Brand Identity Photography & Painting
Chmiel Glassworks
Chmiel Glassworks icon
v1.0.0

Modern responsive website for a family-run glass workshop. Service pages, photo gallery and contact form.

HTML CSS JavaScript
Service Catalog Photo Gallery Contact Form
Knowledge Base

Related Articles

4 Sep 202620 min read

SSR vs CSR vs SSG vs ISR: what to choose for SEO and performance

SSR, CSR, SSG and ISR differ mainly in where and when HTML is generated. For SEO, the key question is whether important content and metadata are available without waiting for client-side JavaScript. For performance, server cost, caching, JavaScript execution, hydration and freshness matter as well. In 2026, the best architecture is usually not one rendering mode for an entire application, but a strategy selected for each route or even each part of a route.

Read article
4 Sep 202619 min read

CORS: what it is and why the browser blocks an API

CORS is not a mechanism that simply blocks connections to an API. It is a browser protocol built on the same-origin policy that decides whether JavaScript from one origin may read a response from another origin. In some cases the HTTP request is sent and the browser only blocks script access to the response. In other cases the browser sends an OPTIONS preflight first and uses its result to decide whether the actual request may be sent at all.

Read article
4 Sep 202621 min read

Core Web Vitals in 2026: LCP, INP and CLS in practice

Core Web Vitals in 2026 still consist of three metrics: LCP for loading the main content, INP for interaction responsiveness and CLS for layout stability. The scores alone do not tell you what to fix. Effective optimization requires separating real-user field data from lab tests, finding the actual LCP element, slow interaction or layout shift source, and then monitoring the result after deployment.

Read article

Ready to launch your web application?

Let's discuss your requirements and create something exceptional.

Contact Us