What kinds of software do you build?

Web and mobile apps, dashboards, cloud services, integrations, and smart-home/IoT automations for domestic use.

How do you work with new clients?

We start with a discovery workshop, propose a roadmap and engagement model, then deliver in small, testable increments.

Do you take on small domestic projects?

Yes—bespoke automations, family safety apps, accessibility tools, and home-data dashboards.

What is your code quality approach?

Secure by default, peer-reviewed, automated tests, and cloud-native reliability.

Organic-Modern Software, Built for People

We design and deliver thoughtful software for businesses and homes—systems that feel warm, reliable, and quietly powerful. From cloud platforms to family apps and smart-home automations, our work blends craft with care.

London • England Trusted • Sustainable

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Our Story

“Citadel” is our promise: your data, your home, your business—kept safe. We build with empathy and iterate with you, turning complex ideas into calm, capable tools.

Discovery workshops & journey mapping
Accessible, inclusive design
Security first, privacy by default
Sustainable delivery, measurable outcomes

Services & Solutions

Illustrated eco-tiles that grow with your needs.

Web & Mobile Apps

Responsive, accessible, app-store ready. React, Native, and modern web stacks.

Design systems & UI kits
Offline-first experiences
App store publishing

Cloud Platforms

Scalable APIs, serverless, and data pipelines on AWS/Azure/GCP with strong observability.

Infrastructure as code
Automated testing
Zero-downtime deploys

Integrations & Automation

From CRMs to smart-home devices, we connect the dots and remove manual toil.

Workflow automation
Secure connectors
RPA where it fits

Domestic / Home Software

Family dashboards, care & safety apps, IoT orchestration with privacy built-in.

Home data hubs
Parental controls
Energy tracking

Data & AI Enablement

Search, summarise, detect and predict—with governance, not hype.

Responsible AI patterns
Analytics dashboards
ML pipelines

Support & Care Plans

Transparent SLAs, performance budgets, and regular improvement cycles.

Proactive monitoring
Incident response
Roadmap reviews

Industries Served

Branches that reach your domain.

Why Choose Citadel Key Systems

Years building software

Client satisfaction (%)

Projects delivered

Week MVP cycles

Secure by Design

OWASP practices, threat modelling, and privacy controls from day one.

Human-Centered

Research, prototyping, and continuous UX testing ensure adoption.

Measurable Outcomes

We define success metrics and ship improvements that move them.

Case Studies & Success Stories

Retail Replatform: 38% Higher Conversion

We rebuilt a legacy store into a composable commerce stack, adding real-time stock and 1-click checkout.

React • Headless

Care Dashboards for Clinics

Accessible patient portals with secure messaging and triage automations lowered wait times by 24%.

Accessibility AA

Smart-Home Hub

Unified control for lighting, energy, and safety—private by default and lightning fast.

IoT • Edge

Fintech API Modernisation

From monolith to microservices with observability; incidents down 70% within 3 months.

Cloud • SRE

Testimonials

Portrait of client — **“They turned our backlog into a breathing product.”** Weekly releases, zero drama.

—Retail Director

Portrait of client 2 — **“Security minded and kind.”** They made our clinic portal genuinely accessible.

—Clinic Owner

Portrait of client 3 — **“Communication A+.”** Clear budgets, clear outcomes, no surprises.

—Operations Lead

Insights & Resources

Domestic Software: Designing for Calm

Principles for useful, respectful apps in the home.

Read • 4 min

Green Cloud Patterns

Lower latency, lower carbon—without compromising reliability.

Read • 6 min

From Idea to MVP in 4 Weeks

Our discovery → prototype → validate loop.

Read • 5 min

Frequently Asked Questions

How soon can we start?

Discovery workshops can begin within two weeks. We then sequence design and engineering for a first release in ~4–6 weeks depending on scope.

Which technologies do you use?

Modern TypeScript/React, Node, Python, cloud-native stacks, and native mobile where appropriate—chosen to fit your team and scale.

Do you offer maintenance?

Yes. Care Plans include monitoring, backups, upgrades, security reviews, and quarterly roadmap sessions.

How do you price projects?

Transparent engagement models—see Pricing below.

Pricing & Engagement Models

Discovery Sprint

£3,500

1–2 weeks of research, workshops, and a clickable prototype.

Stakeholder interviews
User journeys & scope
Delivery plan & budget

Book Sprint

Fixed-Scope Build

From £18k

Well-defined outcomes with a clear timeline.

Milestone billing
Design + Engineering
UAT & training

Get Estimate

Dedicated Team

£8k / mo

Flexible capacity across design, engineering, and DevOps.

Monthly roadmap
Velocity reports
Continuous delivery

Reserve Capacity

Let’s build something meaningful

Tell us about your idea, and we’ll suggest the quickest, safest path to value.

Contact Details

Company: CITADEL KEY SYSTEMS LTD

Phone: 07537132605

Address:
399-405 Oxford Street
Office 7607GB, Unit 5, Area 1/1
London, England, W1C 2BU

Email: contact@citadelkeysystems.com

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