API Development · Derry
API Development in Derry
Building APIs for Derry organisations exposing their systems to partners, customers or their own applications. The design decisions made in the first week are the ones you live with, because once a third party has integrated, changing the contract stops being a technical choice and becomes a negotiation.
Why this comes up
The problem
Partners want programmatic access and the current answer is a nightly file export. Each new integration is bespoke work, and every consumer expects a different format.
What you get
What we deliver
- Resource design and naming settled before implementation, since renaming later is breaking
- Authentication appropriate to the consumers — API keys, OAuth, or mutual TLS
- Versioning strategy decided up front rather than improvised at the first breaking change
- Pagination, filtering and rate limiting, so one consumer cannot degrade the service for others
- Errors that are actionable, with codes a client can branch on rather than prose
- OpenAPI documentation generated from the implementation, so it cannot drift
Want this scoped for your business in Derry?
Thirty minutes, no charge, no sales script. You leave with a written summary of what api development would actually involve — whether or not you use us.
Working in Derry
Northern Ireland
The city is Derry to most of its population and Londonderry in official use, and which name you lead with is read as a statement here — we use Derry in customer-facing copy and note both where a document has to be formal.
Cross-border trading systems for businesses working into Donegal, and manufacturing tooling for the north west.
Sectors we work with in Derry
- Manufacturing
- Healthcare
- Higher Education
- Digital
- Tourism
What we work with
Technologies and platforms
- TypeScript
- Node.js
- PostgreSQL
- OpenAPI
- AWS
Who we work with
Industries we serve
- SaaS platforms
- Financial services
- Logistics
- Manufacturing
- Healthcare
Why us
Why Derry businesses choose Asionis
- Projects typically launched within 4–8 weeks
- No long-term contracts required
- All team members UK-based
- Dedicated account manager and development team
- Transparent reporting with monthly performance metrics
- Scalable from startup to enterprise
How we work
- Step 1
Free consultation
A 30-minute call to understand the problem. You keep the written summary either way.
- Step 2
Proposal
Scope, timeline and a fixed price, in writing, before anything starts.
- Step 3
Build
Short cycles with regular check-ins, so you see progress rather than hear about it.
- Step 4
Launch and support
We handle the go-live and stay available afterwards.
Other services in Derry
Looking for the full picture? See our API Development services, everything we do in Derry or browse everything we do.
API Development in Derry — common questions
- REST or GraphQL?
- REST for most business APIs — it is simpler to operate, cache and explain, and consumers already know it. GraphQL earns its complexity where clients need widely varying shapes of the same data, which is a real problem but a narrower one than its popularity suggests.
- How should we handle versioning?
- Decide before launch. Additive changes need no version; removing or renaming a field breaks consumers regardless of your intent. A version in the path is unfashionable and works, and knowing your policy in advance prevents the awkward first breaking change.
- Do we need rate limiting from day one?
- Yes. A single consumer looping without backoff will otherwise take down the service for everyone, and it is usually a mistake rather than malice. Limits are also easier to relax later than to introduce once integrators depend on unlimited access.
- How much documentation is enough?
- Enough that a competent developer integrates without contacting you — authentication, every endpoint, error codes, and realistic examples. Generating it from the implementation matters more than its polish, because hand-written docs drift and then mislead.
- Do you work with businesses across County Londonderry?
- Yes. We are based in Leicester, United Kingdom and work with clients throughout Northern Ireland, including Derry and the surrounding County Londonderry area. Most collaboration happens remotely, and we travel for kick-offs and key milestones.
- What kind of Derry businesses do you usually work with?
- Cross-border trading systems for businesses working into Donegal, and manufacturing tooling for the north west. Beyond that we work across Manufacturing, Healthcare, Higher Education, Digital and Tourism.
- Do you cover the areas around Derry?
- Yes — we work throughout Northern Ireland, including Belfast, Lisburn. Derry is an urban area of roughly 85,000+, and we take on work across the wider County Londonderry region rather than the city boundary alone.
Talk to us about API Development in Derry
A 30-minute call with someone who would actually work on it. No sales script, no obligation.
- Projects typically launched within 4–8 weeks
- No long-term contracts required
- All team members UK-based
- Dedicated account manager and development team
- Transparent reporting with monthly performance metrics
- Scalable from startup to enterprise