Custom software development means designing and building an application around your own processes instead of bending your business to fit a generic tool. Devsinn builds portals, internal tools, workflow systems and SaaS products for UK businesses, with a fixed scope, weekly demos, UK GDPR-aware design and full code ownership on completion.
What you get
One source of truth
Data entered once and shared across teams.
A process that fits
Your rules, approvals and reports, built in.
Room to grow
Modern architecture that scales without a rebuild.
No lock-in
You own the code, the data and the documentation.
When does custom software make sense?
Custom software pays off when your process is a competitive advantage, when off-the-shelf tools force costly workarounds, or when licence fees grow with every user you hire. If staff spend hours moving data between spreadsheets and systems, a focused custom tool usually returns its cost quickly.
Several tools stitched together with manual exports and re-keying.
Per-user subscriptions that keep rising as you grow.
A process that gives you an edge and does not fit a template.
Customers or partners who need a branded portal.
How much does custom software cost in the UK?
A focused internal tool typically starts from £8,000 + VAT. A first version of a customer portal or SaaS product (an MVP) usually starts from £15,000 + VAT, and larger multi-module platforms from £40,000 + VAT. We fix the price for each phase after discovery, so you never pay for open-ended hours.
Indicative custom software costs (GBP, + VAT)
Project
Typical price
Typical timeline
Discovery and technical roadmap
From £1,950
1 to 2 weeks
Internal tool or workflow system
From £8,000
4 to 8 weeks
Customer portal or SaaS MVP
From £15,000
8 to 12 weeks
Multi-module platform
From £40,000
3 to 6 months
Custom software or off-the-shelf?
Choose off-the-shelf when a mature product already fits most of your process and the licence cost is reasonable. Choose custom when the gaps cost you time every day, when you need to integrate several systems, or when owning the software adds value to your business. A good partner will tell you honestly which is cheaper over three years.
Off-the-shelf versus custom software
Factor
Off-the-shelf
Custom
Upfront cost
Low
Higher
Ongoing cost
Per-user licences
Hosting and support
Fit to your process
You adapt to it
It adapts to you
Integrations
What the vendor offers
Whatever you need
Ownership
Licence only
You own the code
How do you keep a software project on time and budget?
We fix scope and price per phase, demo working software every week, and keep a shared backlog you can see. Changes are priced before they are built, never after. Small, frequent releases mean problems surface early, when they are cheap to fix, instead of at the end.
Written scope and acceptance criteria before build starts.
Weekly demo and a short written update.
A change log with prices agreed before work begins.
What technology do you use?
We choose proven, widely supported technology so any competent team can maintain it later. Typically that means Next.js and React for web front ends, Node.js or Python services, PostgreSQL databases, and Flutter for mobile, hosted on AWS, Azure, Google Cloud or Vercel with automated testing and deployments.
How it works
Free 20-minute call
Your goals, constraints and whether custom software is the right answer.
Discovery and roadmap
Workflows mapped, scope written, risks named and a fixed price per phase.
Build in sprints
Two-week sprints with a working demo every week.
Launch
Data migrated, staff trained and a calm go-live with rollback ready.
Support and growth
Monitoring, security updates and a roadmap for what comes next.
What it costs
Indicative prices in GBP, excluding VAT. We fix the price in writing after a short scoping call. Full price guide
Discovery and roadmap
From £1,950+ VAT
International: From $2,500
Workflow mapping
Written scope and architecture
Fixed quote for the build
MVP or internal tool
From £8,000+ VAT
International: From $10,200
Design and build
Weekly demos
Testing, deployment and handover
Support and hosting
From £400+ VAT
per month
International: From $510
Monitoring and backups
Security updates
Small improvements each month
A good fit if you
UK SMEs outgrowing spreadsheets and disconnected tools
Firms that need a branded customer or partner portal
Founders launching a SaaS product with a clear first version
Not the right fit if you
Needs a mature off-the-shelf product already meets well
Projects without a decision maker who can give feedback weekly
Budgets below the cost of a focused first version
Questions people ask
Still unsure? Ask us on a free 20-minute call.
How long does custom software take to build?
A focused internal tool usually takes four to eight weeks. A customer portal or SaaS MVP takes eight to twelve weeks, and larger platforms three to six months, released in phases. Discovery adds one to two weeks up front and gives you a dated plan before you commit to the build.
Who owns the software and the intellectual property?
You do. On payment, the code, designs and documentation are yours, assigned in the contract. Repositories and cloud accounts sit in your organisation's name, so you can switch suppliers or bring development in-house at any time without asking our permission.
Can you work with our existing systems?
Yes. Most projects connect to systems you already use, such as Microsoft 365, Xero, Sage, HubSpot, Salesforce or an existing database. We confirm each integration during discovery, test it early in the build, and flag any limits before they affect the timeline.
Is the software UK GDPR compliant?
We design for UK GDPR from the start: data minimisation, role-based access, encryption in transit and at rest, audit logs, retention rules and support for subject access requests. We provide documentation for your records. Your organisation remains the data controller and decides how data is used.
What if the project goes wrong or runs late?
Fixed phases limit your exposure: you only commit to one phase at a time. Weekly demos show real progress, so slippage is visible early. If we miss an agreed milestone through our own fault, we keep working on that phase without extra charge until it meets the written acceptance criteria.
Do you provide support after launch?
Yes. Most clients take a monthly support plan from £400 + VAT covering hosting, monitoring, backups, security updates and small improvements. You can also choose to support the software in-house; we hand over full documentation and a walkthrough for your team.
Can you take over software another agency built?
Usually, yes. We start with a paid code and infrastructure review, explain what we find in plain English, and recommend whether to stabilise, refactor or rebuild parts of it. You get an honest assessment even if the answer is that the current code is fine.
