Website Development Agency

Assertive provides professional website development solutions for businesses looking for custom web development.Custom PHP, .NET & JS/Angular Solutions, WordPress Dev & More.

Web Development Solutions

We offer a wide range of bespoke web development solutions for medium to large organisations looking for bespoke websites, platforms, SAAS solutions & geneal development.

Assertive supports businesses across London, the UK and worldwide with bespoke web development solutions. We have a strong team of highly qualified web developers who specialise in Java, Javascript, Python, Ruby on Rails, Angular, .NET and PHP.

If you are looking to build a platform, develop a SAAS platform, require custom modules to facilitate CMS/website functionality, or whether you need to migrate from one CMS to another – our 50+ strong team of web developers can help.

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Assertive is the #1 healthcare SEO agency

For over 15 years, Assertive has been delivering SEO for healthcare clients. Our approach to healthcare SEO is rooted in a deep understanding of the industry's nuances and the critical nature of healthcare decisions.

We combine this knowledge with revolutionary SEO techniques, setting a gold standard in healthcare digital marketing.

Our data-driven, patient-centric strategies are designed to position you as the leading choice in a crowded digital landscape, standing out in the search engines as the #1 healthcare service provider in your field.

Case Study

One of our most recent website development case studies


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The Craft Irish Whiskey Co.

Assertive worked with the prestige Craft Irish Whiskey Co. brand on the design cut up and development of the new website. The custom development included advanced video blending & menu animations.

We were thoroughly pleased with the website work delivered by Assertive. We wouldn’t hesitate to recommend them to other brands looking for something unique.

James Bradley  – Director

The Craft Irish Whiskey Co is a high net worth whiskey producer – producing high end luxury whiskies in partnership with established luxury brands such as Faberge.

Examples of Our Development Work


Assertive delivered a full website design & build project for SCI-MX which involved dual CMS integration, customisation, user experience exercises, SCHEMATICS, product categorisation, content creation & concepts. Assertive has delivered a performance website with new dynamic functionality to improve accessibility to products & content.

Oxford City Council Growth Board

Assertive worked on Oxford City Councils growth board website. The growth board is a joint committee of six councils within Oxfordshire. Assertive produced the branding, website design, layout and website structure for OGB before developing the platform and providing training for team members to use.

Oxford City Council Direct Services

Assertive worked on the Oxford Direct Services website which is a commercial division of Oxford City Council. Assertive helped transition the Oxford Direct Services website away from Jadu Contiuum on to a new CMS platform. Assertive built in new functionality, online MOT booking & delivered an SEO strategy.

Dream Cottages

Assertive designed & built the Dream Cottages website with an API driven booking & property management system fully integrated. The design and build took into consideration user experience, easy access to information, properly structured URL architecture & site performance.

We specialise in development but regularly assist clients with CMS migrations and complete website re-designs. From bespoke designs and mock-ups through FIGMA through to full modular wireframing, design & UX planning.

If as an organisation or growing business – you’ve outgrown your existing website and need something more modern, faster, better at converting – why not see how Assertive could help with a complete website re-design and overhaul.

Our designers produce high quality designs that take into account brand, consistency, layout, UX, mobile first design & full design planning. We’re not just able to design stunning, eye catching design – we’re able to build functional UX that will take into consideration the needs of your end users.

Good design is as much about planning as it is design – a functional UX inside the design is crucial in today’s mobile first world. Our development services integrate with design – so we can either retrofit a design to your existing content management system, or, we can help with a new design and CMS migration.


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How We Can Support Your Development Needs


We provide high quality, QC backed development for medium to large organisations. We can support complex development requirements as well as on-demand development support.

What Development We Offer

Assertive provides full development services across most major web development languages & technologies. We can re-design & re-develop websites to enhance performance and functionality. We work with PHP, .NET, Javascript, Angular, Ruby on Rails, HTML5 and more. Our development team has helped businesses to build custom websites, custom website platforms, APIs, data tools, management tools, user interface tools & more.

What CMS Platforms We Work With

Assertive works with over 25 different CMS platforms including WordPress, Joomla, Drupal, Magento, Umbraco, DotNetNuke, SiteCore, Grav & more. Our developers can develop bespoke solutions for each CMS including enhanced templates, layouts, functionality & more. Our developers can also work with custom CMS platforms built in PHP / .NET.

The Costs for Web Development

Assertive’s hourly rate for ad-hoc web development starts from £75 per hour. Some web development projects can be quoted in advance to a fixed budget. Our costs will vary depending on the work and complexity of the work involved. Please get a quote for accurate web development costs.

Quality Control & Testing

Assertive’s development team have strict quality control testing & checking procedures to ensure high quality work-output. Online website development and platforms is subject to our test accelerator tests for cross device & browser compatibility.

We’ll spend time getting to know you and your brand to understand end to end requirements. We listen, absorb what it is that, as a business, you require. From there we produce a brainstorm / specification.

Once we have a scope of what it is you require, budgets, deadlines and any specific process requirements, we provide a quote to get the work done, be it development, design or a mix of both.

We produce a plan of action, GANTT and a schedule of work so that you can understand when your project will be delivered, the feedback phase, development phase and sign off phases.

Web Design & Web Development projects vary wildly – so every web design or web development quote is bespoke.

 You’ll be given a dedicated project manager who will see your project through from discussion to delivery, through QC and testing.

We aim to take all of the pain & logistical headaches out of delivering web development projects, web design projects, SAAS projects & more.

Our Web Design & Development Process

Web Development Services


Our website development services are comprehensive, covering almost any coding requirement for website design, structure, functionality & performance.

WordPress Development

Assertive provides full wordpress development, customisation and performance services. We can code custom functionality, improve site performance & speed, integrate new tools, build custom plugins, customise the CMS and more.

WordPress Page Speed Fixes

Our development team can help significantly speed up WordPress with full compliance with Google PageSpeed Insights / Google Lighthouse. We’ll turn desktop and mobile speed scores around for blisteringly fast performance.

Drupal Development

Assertive provides full Drupal website customisation, platform adaptations, new plugins/functionality, security updates and speed optimisation. We can provide custom code for Drupal with bespoke plugins & APIs.

.NET / Angular / Laravel

Assertive provides comprehensive website technology coverage for website development & platform integration. Our developers work with .NET, Angular & Laravel frameworks as well as custom PHP / Java sites.

Custom Website Platforms

Assertive can plan, spec and develop custom website platforms for businesses. From bespoke quote tools to financial platforms, our developers can build complex tools, UI, frameworks & custom functionality.

Website CMS Migrations

Assertive can provide complete website CMS migrations for businesses looking to switch to a new content management system. Our website migration service can help shift entire websites & frameworks on to new content management platforms

Site & Database Architecture

Assertive can provide website architecture updates as well as database upgrades, fixes and testing as part of website health checking & management. Assertive provides full guidance on optimal database architecture & website structure.

On-Demand Web Development Support

Assertive can provide on-demand website development support as well as out of hours development management. Our on demand team can respond to most web development requirements within 4-6 hours.

Why Choose Assertive for Development? 

Experienced Specialists

Assertive’s developers have a minimum of 5 years of experience in any single website development language/technology. We have a team of specialist developers who can extensive experience coding and building web apps in PHP, .NET and Java.


Our development team always works hard to deliver the highest quality of work. Our developers go through strict testing before any website development solution is deployed. We deliver high quality development solutions without compromise.

Best Practise

Assertive adopts best practice in all website development projects. We perform rigorous testing as well as mobile and tablet device testing. Using best practice, we build websites for the end user which engage and deliver.

Speak to Assertive’s Web Development Team

Call us now:

0207 965 7623

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