Most people come to us with a problem and a blank page. Three weeks later there's a product with real users in it.
Software, built fast and priced fairly.
catalyst4 is a small software agency in Belfast, working with startups and small businesses. We ship working product in weeks, not quarters, at a price that makes sense before you've raised a round or hired a team.
Start fresh, finish fast
What we build
- Web applications
- Customer-facing products, portals and dashboards. The thing your business actually runs on.
- Mobile apps
- iOS and Android from one codebase, so you get both without paying for two.
- MVPs and prototypes
- Enough product to put in front of real users and investors, built to be extended rather than thrown away.
- Internal tools and automation
- Replace the spreadsheet, connect the systems, remove the Tuesday afternoon of copy-and-paste.
Selected work
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Ledgerly
Bookkeeping for freelancers that pulls bank feeds, categorises spend and produces a quarter-end pack an accountant will accept.
Live in seven weeks. 1,200 paying users in the first six months.
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Northfield Vets
Online booking and reminders for a three-branch veterinary practice, integrated with the system they already had.
Phone bookings down 60%. Missed appointments down by a third.
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Stackline
MVP for a pre-seed logistics startup: shipment tracking, carrier quotes and a customer portal.
Used to close a £1.4m seed round. Still the core product two years on.
Our own products
Between client projects we build and run software of our own. Same small team, same stack, same weekly ships. Living with the results keeps us honest about what we recommend to everyone else.
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Proper Agent
An AI property manager and letting agent.
It answers enquiries, arranges viewings, keeps on top of the paperwork and chases what needs chasing, so a landlord or small agency isn't doing it at eleven at night.
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everyjob
Field management software for sole traders and small businesses. Jobs, quotes, scheduling and invoices in one place, on the phone you already carry.
Based in Belfast
We're in Belfast, Northern Ireland, and work with clients across the UK and Ireland. If you're nearby we'll happily come to you; if you're not, everything works just as well on a call.
How we work
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A short call. Thirty minutes to understand what you need and whether we're the right people to build it.
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A fixed quote within two working days. Scope, price and timeline in plain English. If it changes, we tell you before it costs you.
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Something you can use every week. We ship to a live environment from the first week. You see progress, not status reports.
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Handover, with the code yours. Clean repository, documentation, and help hiring or onboarding whoever takes it on next.
On price
Fixed quotes, agreed before we start. No hourly surprises, no retainer you didn't ask for.
We keep costs down by keeping the team small and the stack boring. Two or three people who've built this kind of thing before, using tools we already know well. You pay for the product, not for meetings about the product.
Who we work with
A good fit
- Startups from idea to Series A
- Small businesses outgrowing spreadsheets and off-the-shelf tools
- Founders with a clear problem and a real deadline
- Teams who need a second pair of hands for a few months
Probably not
- Enterprise procurement cycles
- Twelve-month roadmaps fixed on day one
- Anything that needs a committee to say yes
Common questions
How much does a project cost?
It depends on what you're building, so we won't pretend there's one number. What we can promise is a fixed quote within two working days of a call, and that the quote is the price. If the scope moves, we re-quote before we carry on, not after.
How long does it take?
Most first versions ship in three to seven weeks. You'll have something live to click on from the end of the first week, and we'd rather cut a feature than slip a date.
Who owns the code?
You do, from the first commit. We work in a repository under your account, with no licences, no lock-in and nothing held back until the final invoice clears.
What if we don't know exactly what we want yet?
That's normal. The first call is for working out what the first version actually needs to do, and the quote is for that. Everything else goes on a list for after you've watched real people use it.
Can you work with our existing code or team?
Yes. Plenty of our work is adding to something that already exists, or lending a second pair of hands to a team that's stretched. We'll be honest early on if the codebase needs attention before new features are worth building.
What happens after launch?
Handover is part of the job: a clean repository, documentation, and help hiring or onboarding whoever takes it on. If you'd like us to stay involved we can agree a monthly arrangement, but you're never tied in.
Do we need to be in Belfast?
No. We work with clients across the UK and Ireland, and everything works just as well on a call. If you are nearby, we'll happily come to you.
Have something in mind? Tell us about it.
A sentence or two is plenty. We reply within a working day.