Web application development services

Web application development services cover the planning, design, development, testing, deployment and ongoing support of browser-based applications that help organisations deliver secure digital services, automate business processes and improve customer and employee experiences.

Unlike traditional websites, web applications allow users to interact with data, complete tasks and access business systems online. At CACI, our web application development services combine user-centred design, software engineering, cloud-native development and systems integration to create bespoke applications that are secure, scalable and built around your organisation’s needs.

The right web application approach depends on your users, business processes and long-term objectives. In some cases, a fully custom web application is the best way to support unique workflows or complex integrations. In others, an open-source or off-the-shelf solution can provide a strong foundation that reduces delivery time and cost.

Rather than forcing your organisation to adapt to standard software, we recommend the most appropriate route and customise it around your needs. This may include configuring, extending or integrating an existing platform, or developing bespoke functionality where required, so the final solution supports your users, workflows and wider technology landscape while remaining flexible, scalable and able to evolve as requirements change.

We develop a wide range of bespoke web applications, including headless content management solutions using platforms like Contentstack or Storyblok, customer portals, employee portals, self-service platforms, workflow management systems, business applications, SaaS platforms, dashboards, booking systems and case management solutions.

Whether you’re developing a new digital service or modernising an existing platform, our applications are designed to improve operational efficiency, enhance user experiences and integrate seamlessly with your wider technology ecosystem.

We use AI to accelerate delivery across the software development lifecycle, from discovery and requirements definition through prototyping, development, testing and documentation.

AI helps us structure briefs into journeys, requirements and assumptions, create rapid prototypes, support specification, assist with code drafting, refactoring and test generation, and improve technical documentation. However, AI does not replace delivery expertise: our consultants validate findings, clients approve working prototypes and specifications, and engineers remain accountable for solution design, production logic, code review, security and quality. This allows us to compress time without compressing standards.

Yes. We help organisations modernise legacy web applications to improve performance, security, scalability and maintainability while reducing technical debt.

Depending on your objectives, this may include application re-platforming, refactoring, cloud migration, API development and integration, or migrating monolithic applications to modern cloud-native architectures. Our approach enables organisations to maximise existing technology investments while creating digital platforms that are ready for future growth.

We use a range of modern technologies to deliver secure, scalable web applications, selecting the most appropriate technology stack based on your business requirements, existing architecture and long-term objectives.

Our expertise spans frontend frameworks including React, Angular, Vue.js and Next.js, backend technologies such as .NET, Node.js, Java and various PHP frameworks (such as Laravel), and cloud platforms including Microsoft Azure and Amazon Web Services (AWS).

Where content management is required, we also work with API-first headless CMS platforms such as Contentstack and Storyblok.

We also develop API-first, cloud-native applications using containerisation, microservices and DevSecOps practices where appropriate

Security is embedded throughout our software development lifecycle, ensuring every web application is designed to protect users, business data and critical services.

We follow secure coding practices aligned with OWASP guidance and implement robust security controls including OAuth 2.0, Single Sign-On (SSO), multi-factor authentication (MFA), encryption and role-based access control. Combined with automated security testing, vulnerability management and DevSecOps practices, this helps organisations reduce risk while meeting governance and compliance requirements.

The timescale for custom web application development depends on the complexity of the solution, required functionality, integrations and business objectives.

Smaller applications can often be delivered within a few weeks, while larger enterprise web applications are typically delivered through phased, agile releases over several months. This iterative approach enables organisations to prioritise functionality, gather user feedback and realise business value earlier while continuing to enhance the application over time.

The cost of web application development services varies depending on the application’s complexity, functionality, integrations, security requirements and ongoing support needs.

Rather than offering a one-size-fits-all solution, we work closely with organisations to understand their objectives, users and existing technology landscape before recommending the most appropriate approach. This ensures your investment is focused on delivering measurable business outcomes, long-term scalability and value.

A website is primarily designed to present information from a CMS, while a web application enables users to interact with data, complete tasks and access business functionality through a web browser.

For example, a website with a CMS might showcase products or services, whereas a web application could enable customers to manage accounts, submit applications, make bookings, complete transactions or collaborate with colleagues. Web applications typically include secure authentication, business logic, systems integration and personalised user experiences, making them a fundamental part of modern digital transformation.