02 · CUSTOM SOFTWARE
Custom software built to be handed over
Off-the-shelf stops fitting at the point your process becomes the thing you compete on. We build the systems that sit at that point: internal platforms, customer-facing products, and the integration layer that makes the rest of your stack behave as one thing.
- Product Discovery
- Platform Architecture
- API & Integrations
- Legacy Modernisation
What we build
Four kinds of engagement, from a blank page to a system that has outlived its architecture.
Product discovery
Before a screen is drawn. What you are trying to move, what already exists, and what the real constraint is — so the brief matches the problem rather than the first description of it.
Platform architecture
The structural decisions that are expensive to reverse: data model, service boundaries, and where the consistency guarantees live.
API and integrations
The layer where most internal software actually fails. Typed contracts, retries that are safe to retry, and failure states that surface rather than hide.
Legacy modernisation
Incremental replacement rather than a rewrite you cannot ship. The old system keeps running while the new one takes traffic a route at a time.
What ships with it
Typed codebases, tested pipelines, CI, observability and documentation. The goal is not that the software works on the day it launches — it is that your team can change it safely a year later, without us.
2 of these are live right now
Not a portfolio of screenshots — every one of these opens.
ArchitectXpert
AI floor plan generator
A generator that takes plot size, floors, bedroom and bathroom counts, city and house style, then produces a dimensioned architectural plan with room labels, door placements and a total area breakdown. Output downloads as PNG or DXF for AutoCAD, so an architect or contractor can pick the drawing up and keep working in it.
architectxpert.tech ↗H&B Event Solution
Event production storefront
A production-grade brand site that leads with the work: full-bleed event photography, a service breakdown for 3D stall fabrication, SMD screens and sound, a portfolio clients can share, and quote requests captured as structured enquiries instead of chat messages.
hbevents.me ↗
What we build on
- TypeScript
- Go
- Postgres
Halyx is not religious about the stack — it picks what your team can maintain — but these are the defaults it is fastest and safest in.
Questions we get asked first
- Do you do fixed-price or time and materials?
- A paid discovery sprint first, then a fixed-scope build. Fixed scope is only honest after discovery; before it, any fixed price is a guess with a margin on top.
- Can you take over a codebase somebody else wrote?
- Yes. That starts with a read-only assessment and an honest report — sometimes the answer is that incremental replacement beats continuing.
- What stack do you build in?
- TypeScript, Go and Python on the backend, Next.js and React Native on the front, Postgres and Snowflake for data, AWS for infrastructure. We are not religious about it and will pick what your team can maintain.
The other four practices
Talk to the people who would build it
The first conversation is a scoping call, not a pitch: what you are trying to move, what already exists, what the constraint is. It ends with either a range and a proposed first step, or a straight answer that Halyx is not the right fit.