You bought five SaaS tools to run a Derry business, and not one of them understands a cross-border deal
Custom software for a Derry firm runs $50k to $150k over 3 to 9 months, scoped to the problem. You build it when generic off-the-shelf SaaS forces your cross-border, dual-currency, dual-VAT operation into a single-country mould, and you're paying the difference in manual workarounds, spreadsheet glue and lost margin. The custom case is encoding the specific way a North West business actually trades.
Generic SaaS is built for the median customer, and the median customer trades in one currency under one tax authority. A Derry tech or medical-device firm is not the median customer. Your operation crosses the UK and Ireland border constantly, so every SaaS tool you adopt covers eighty percent of the job and leaves the cross-border twenty percent to a person and a spreadsheet.
Individually those gaps look small. Together they're a tax on the whole business: the conversion someone does by hand, the VAT call someone makes from memory, the customs field someone re-keys between two tools. Custom software exists to close the specific gaps that generic SaaS structurally can't, because no global vendor is going to build for the North West border in particular.
What breaks first in Derry
- Every SaaS tool covers the domestic case and leaves cross-border handling to manual workarounds
- Logic that's specific to your business living in people's heads because no off-the-shelf tool models it
- Data re-keyed between disconnected SaaS tools, introducing errors on every cross-border job
- Paying for multiple SaaS subscriptions whose overlap and gaps you're patching with staff time
The fix: custom software built for Derry, not rented
Custom software is worth building precisely where your business is different from the SaaS median, and for a Derry firm that difference is the border. A custom system encodes your cross-border rules, your dual-currency margin maths and your specific VAT logic directly, so the twenty percent that SaaS can't handle stops costing you staff hours and lost margin. You build the part that's genuinely yours and integrate the commodity parts you can buy.
What custom software costs in Derry
| Project scope | Typical cost | Timeline |
|---|---|---|
| Focused system solving one cross-border problem | $50k to $85k | 3 to 5 months |
| Platform replacing several SaaS gaps | $90k to $150k | 6 to 9 months |
| Discovery + prototype to de-risk before committing | $15k to $30k | 4 to 6 weeks |
The capability list that earns its budget
What we build under custom software in Derry
The engagements Derry teams bring us most often: microservices, database design, bespoke software development, SaaS development, web application development and enterprise software.
Exactly what you get
You get software built around the part of your business that's genuinely different: the border. Your cross-border rules, dual-currency margin maths and VAT logic are encoded and enforced, the manual glue between SaaS tools disappears, and you get honest cross-border profitability. The commodity parts stay on the accounting software, CRM (Customer Relationship Management) and inventory tools you already buy, connected through clean integrations rather than re-keying.
How to choose a developer in Derry
The best sign is a developer who tells you what not to build. A team that says 'keep your accounting on Xero, keep your CRM, and let's build only the cross-border core that nobody sells' understands the economics of custom software. The North West rewards practical delivery, so favour someone who scopes tightly and ships, and ask for a custom system they built that deliberately left commodity work on SaaS.
- !They want to custom-build things you could obviously buy. Ask which parts should stay on SaaS and why
- !No discovery before a fixed quote. Ask them to map your cross-border process before pricing it
- !They don't ask what makes your business different. Custom only pays off on the parts that are genuinely yours
- !No integration plan with the SaaS you keep. Ask how the custom core talks to your accounting and CRM
- !They over-promise a single system for everything. Ask what they'd deliberately leave on off-the-shelf tools
Most Derry teams pricing custom software end up comparing notes on website, inventory management, warehouse management too; the systems share one data spine.
Rohan advises mid-market and enterprise teams on ERP, CRM and custom software, and has led delivery on dozens of business-software builds.
Writes for Digital Heroes, shipping business software for 2,000+ brands across 55+ countries since 2017.
Frequently asked questions
When is custom software worth it over buying SaaS?
When the process is core to your business and genuinely different from the SaaS median. For Derry firms that difference is almost always the cross-border, dual-currency operation. Build the part that's yours and that no vendor will build for you; keep the standard parts on SaaS.
Won't a custom build cost more than another SaaS subscription?
Up front, yes. But if you're paying staff to glue SaaS tools together and patch cross-border gaps by hand, those hours and the errors they cause are a recurring cost too. Custom pays back when it removes that ongoing manual tax and unlocks accurate cross-border margins.
How do we avoid over-building?
Scope tightly. A good developer keeps your commodity processes on existing SaaS and builds only the cross-border core that no vendor offers. A discovery and prototype phase for $15k to $30k de-risks the decision before you commit to the full build.
What does custom software cost for a Derry SME?
A focused system solving one cross-border problem runs $50k to $85k over 3 to 5 months. A broader platform replacing several SaaS gaps runs $90k to $150k over 6 to 9 months. A discovery and prototype to de-risk first is $15k to $30k.