Web applications
Web applications that stay fast, accessible and secure as they grow
Customer portals, internal tools and web platforms with modern front ends and well-tested APIs.
Overview
A web application is often the first thing your clients touch and the tool your staff use all day. It has to load quickly on a slow connection, work with a keyboard and a screen reader, and keep data safe while it does.
We build customer portals, self-service platforms, back-office tools and dashboards with React, Next.js, Angular or Vue on the front end and well-tested APIs behind them. Pages render on the server where that helps speed and search, and in the browser where the interaction needs it.
Every application we build supports the languages and layouts your users need, including Arabic and other right-to-left scripts, and is designed to meet WCAG 2.2 AA. Performance budgets and security checks run in the pipeline, so the application stays fast and safe as features are added.
What we deliver
Flows and interface design
User flows, wireframes and a visual design, agreed with you before the build.
Front-end application
A responsive interface built from reusable components, working on phones, tablets and large screens.
Back-end services and APIs
Documented APIs that hold the business rules and connect to your databases and other systems.
Sign-in and permissions
Single sign-on through OpenID Connect or SAML where you need it, with roles and permissions enforced on the server.
Languages and right-to-left layouts
Text kept out of the code and translated per language, with layouts that mirror correctly for Arabic.
Accessibility evidence
Automated and manual checks against WCAG 2.2 AA, with the results recorded for each release.
Performance budgets
Agreed limits for page weight and load time, checked automatically on every change.
Deployment and monitoring
A pipeline to each environment, with error tracking and uptime monitoring from the first release.
How we work
- 01
Understand users and tasks
We learn who uses the application, on which devices, and which tasks matter most.
- 02
Design and prototype
We design the key flows and test a clickable prototype with real users before building.
- 03
Build in increments
We deliver working features in short iterations, each one reviewed, tested and demonstrated.
- 04
Check speed, access and security
We test performance, accessibility and security before every release, not only at the end.
- 05
Launch and improve
We release through the pipeline, watch real usage and errors, and improve from what we see.
Technologies
- Languages
- TypeScript
- Java
- PHP
- Frameworks
- React
- Next.js
- Angular
- Vue.js
- Node.js
- NestJS
- .NET
- Spring Boot
- Laravel
- Databases
- PostgreSQL
- Redis
- MySQL
- Testing
- Playwright
- axe-core
- Design and accessibility
- WCAG 2.2
- Integration
- GraphQL
- REST
- Identity and access
- OpenID Connect
- SAML 2.0
Ways to work with us
- Project-based deliveryXSIS delivers an agreed scope against written acceptance criteria, with a named delivery lead.
- Dedicated teamA complete team that works only on your product, run day to day by XSIS and directed by you.
- Staff augmentationEngineers and specialists who join your team, work in your tools and report to your managers.
Questions and answers
Which front-end framework do you use?
We use React with Next.js for most new applications because it supports server rendering, has strong tooling and is widely known by engineers. We also work with Angular and Vue, and we continue in the framework you already use when that is the sensible choice. The decision depends on your team’s skills, what the application must do and what you will maintain afterwards.
Link to this questionWhat affects the cost of a web application?
The number of user roles and workflows, the integrations behind the application, the languages and layouts it must support, and its security and audit needs. Design depth matters too: a tool for a small internal team needs less than a public portal your clients rely on. We estimate from the backlog after discovery, so you can decide what goes into the first release.
Link to this questionWill the application be accessible?
We design and build to WCAG 2.2 AA. That covers keyboard use, screen readers, colour contrast, focus order, text resizing and clear error messages. Automated checks run on every change, and we test the key journeys by hand with assistive technology before each release. If your organisation follows a stricter standard, we work to that one.
Link to this questionCan the application support Arabic and other languages?
Yes. We keep every piece of text out of the code so it can be translated, and we lay out pages with logical properties so they mirror correctly for right-to-left languages such as Arabic. Dates, numbers and currencies follow each locale. We plan this from the start, because adding a second language to an application built for one is far more work.
Link to this questionHow do you secure a web application?
We follow the OWASP guidance: input validation, output encoding, protection against cross-site request forgery, secure session handling and a strict content security policy. Permissions are checked on the server, never only in the browser. Dependencies are scanned for known vulnerabilities on every build, and we run security tests before each release. A specialist penetration test can be added before launch.
Link to this questionHow do you keep the application fast?
We agree a performance budget at the start, covering page weight and load time on a typical phone and connection, and check it automatically on every change. Pages render on the server where that helps, images and scripts load only when they are needed, and data is cached close to users. Real-user monitoring after launch shows where the application slows down.
Link to this questionWho owns the code and the work you produce?
Intellectual property in the work we build for you is yours from the first commit — no assignment step at the end. That covers the custom code, documentation and other deliverables made for you. Anything we bring that existed before, such as internal tools or libraries, stays ours, and you receive a licence to use it in your systems. Open-source components keep their own licences, and we list them for you.
Link to this questionWhat support do you provide after go-live?
We can run and maintain what we build: monitoring, incident response, security updates, and changes as your business and its partners change. Support is agreed in writing, with response targets, escalation contacts and regular reporting. Our team is available 24/7.
Link to this questionTell us what you need to build or connect.
Describe the systems, the timeline and the constraints. The right engineers take it from there.
- Our team will call you within 24 hours during your preferred time slot
- Our team is available 24/7