Web Applications Built toCarry Real Business LoadReact, Next.js and Node — Specified, Priced, and Owned by You.
A website has visitors; a web application has users who depend on it to do their job. That difference shows up in permissions, audit trails, background jobs, and what happens at 4pm on the busiest day of your month. We specify all of it in writing before development starts.
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Web Application Development Services We Deliver
From a first SaaS release to a decade-old internal system that needs rescuing — scoped, specified, and delivered by our in-house team of 150+ engineers.
SaaS Platform Development
Multi-tenant products built to onboard customer number one thousand.
- Multi-tenant data architecture
- Subscription billing & metering
- Role-based access control
- Self-serve onboarding flows
Customer Portals & Dashboards
The self-serve layer that takes work off your support inbox.
- Account & document self-service
- Real-time reporting dashboards
- Data export & scheduled reports
- SSO & identity federation
Enterprise Apps & Internal Tools
Line-of-business systems that replace the spreadsheet everyone fears.
- Workflow & approval engines
- Audit trails & compliance logging
- Granular permission models
- Legacy data migration
API & Integration Layer
Making your systems talk without a nightly CSV in between.
- REST & GraphQL API design
- Third-party & ERP integrations
- Webhook & event pipelines
- OpenAPI documentation
Progressive Web Apps
App-like behaviour without an app store between you and your users.
- Offline-capable service workers
- Installable home screen apps
- Web push notifications
- Background sync queues
Legacy Web App Modernisation
Incremental rescue, not a risky big-bang rewrite.
- Strangler-pattern migration
- Framework & runtime upgrades
- Performance & query optimisation
- Security & dependency remediation
Why UK Businesses Choose Mtoag for Web Application Development
Three things that separate us from every other agency in the UK.
Fixed-Price. No Surprises.
Before writing a line of code, we produce a Technical Specification — a fixed-price, fixed-scope document listing every feature, integration, and delivery milestone. You sign it. We build it. The price you sign is the price you pay.
150+ In-House Engineers. No Subcontractors.
100% of Mtoag's engineering work is done by direct employees — never freelancers, never agencies, never offshore subcontractors. Your senior developer has worked at Mtoag for an average of 4+ years.
Full IP Ownership from Day One.
Your source code, design files, and all intellectual property transfer to you on final payment. We sign an NDA before any technical discussion. No vendor lock-in.
The Tech Stack That Powers Our Solutions
Sixteen years of production experience across mobile, web, enterprise, open-source, and search — every technology below is one we ship for UK clients, not just list on a page.
From native performance to cross-platform speed, we build mobile experiences that feel first-class on every device.
Modern, fast, accessible websites and web apps built on frameworks that scale with your business, not against it.
Enterprise-grade architecture built for security, compliance, and systems that need to talk to each other reliably.
Proven open-source platforms customised and hardened for real commercial traffic — not a stock install.
Technical SEO built into the codebase from day one — because rankings are an engineering outcome, not a marketing add-on.
All versions current as of July 2026. We track and adopt major releases within 90 days.
Web Application Case Studies
All projects live in production since launch.
Our Web Application Development Process
The same six-step process on every project. No improvising. No scope creep. No surprises.
Discovery and Technical Scoping
A structured 45-minute discovery call followed by a written Technical Specification defining every feature, integration, permission model, and performance target. You review and sign it before we charge a penny.
Architecture and Prototype
Data model, API contract, and hosting decisions documented up front, plus a working prototype of the core flows so architecture is validated before full development begins.
Agile Development and Build
Two-week sprints with a live staging environment accessible 24/7. Weekly video demos and Slack access to your project manager. All code reviewed by a senior engineer before it merges.
Quality Assurance Testing
Automated unit, integration, and end-to-end testing, manual regression, plus a full accessibility and performance audit before anything ships to production.
Launch and Monitoring
Zero-downtime deployment with instant rollback capability. Error tracking and performance monitored for 30 days post-launch, with fixes included in the launch fee.
Support and Ongoing Development
Post-launch SLA options from 8-hour response to 24/7 monitoring. Monthly security patches, dependency updates, and performance reports. Feature development available on sprint retainer.
All timelines are fixed in the Technical Specification.
Start Your Project — Get Free AuditWeb Application Quality Standards
Every Mtoag project is measured against the same benchmarks before it ships.
- Google Lighthouse Performance: 90+ target on every project
- WCAG 2.2 Level AA: all interactive elements, contrast, and keyboard navigation tested and passed
- Core Web Vitals: LCP under 2.5s, INP under 200ms, CLS under 0.1 — measured on real UK network conditions
- Cross-browser and cross-device tested before every release
Web Application Development Questions Answered
10 direct answers. No sales language.
Web applications typically run £12,000–£90,000 depending on scope. A focused internal tool or MVP starts around £12,000; a multi-tenant SaaS platform with billing, integrations, and a permission model sits at the upper end. Mtoag quotes a fixed price from a written Technical Specification rather than an hourly estimate.
A website mainly presents information; a web application does work on a user's behalf — accounts, permissions, stored state, background processing, and integrations with other systems. That difference is why web apps need a data model and a permission design before any interface work starts.
Six to twelve weeks from signed specification to launch is typical. A focused internal tool can ship in four; a multi-tenant SaaS platform with billing and integrations takes twelve to twenty. Your timeline is fixed in the specification before development begins.
Most Mtoag web applications are built on Next.js and React with a Node or PHP API layer and PostgreSQL, hosted on AWS. We recommend a stack during scoping based on your team, your integrations, and who will maintain it — not on what we happen to like this year.
Yes. Integration work is a normal part of most projects — ERP, CRM, accounting, payment providers, and legacy internal databases. Where a system has no usable API we build an integration layer around it rather than forcing a migration you did not ask for.
Scaling requirements are set during scoping, so the architecture matches the load you actually expect rather than a hypothetical. We document the expected ceiling and the first bottleneck you would hit beyond it, so scaling later is a planned piece of work, not an emergency.
We set up and configure your infrastructure — typically AWS or Vercel — in accounts that you own, with infrastructure-as-code checked into your repository. You are never locked into hosting through us, and you can move providers without our involvement.
You do, 100%. Source code, infrastructure configuration, and all intellectual property transfer to you on final payment, written into every Mtoag contract as standard. Your data lives in your own cloud accounts throughout.
Yes. We start with a paid technical audit of the codebase, infrastructure, and test coverage, then give you a fixed price for two options — stabilise and continue, or rebuild. About half the systems we audit are worth continuing with.
Every project includes a 30-day post-launch window covering bug fixes at no extra cost. After that, retainers cover monitoring, security patching, dependency updates, and ongoing feature development in two-week sprints.
Still have questions? Call our team: +44 (115) 888-0557
Serving Web Application Clients Across the UK
UK project managers available for on-site visits. Remote delivery available worldwide.
Let's Build Your Web Application.
Free Audit. No Commitment.
Tell us what you need to build. We'll send a free Technical Specification within 5 business days — with fixed scope and fixed cost.