Full-stack & mobile application development
End-to-end web and mobile builds — data model, API, and interface delivered as one system by a senior, in-house UK team.
Last updated:Full-stack application development is the end-to-end build of a web or mobile product — data model, API, and user interface — delivered as a single working system rather than disconnected parts. Revenant Systems builds production full-stack applications in Go, Node.js, and Python, with Astro and HTMX front ends and React Native (Expo) mobile apps.
What does full-stack development include?
Full-stack development covers every layer of an application: the database and data model, the server-side API and business logic, and the front-end interface users interact with. A full-stack engagement delivers all three layers as one coherent system, so the data model, API contract, and interface ship and evolve together.
Revenant Systems builds each layer in-house — Go, Node.js, or Python services behind Astro and HTMX interfaces — so there is no hand-off gap between back end and front end.
- Database and data-model design
- Server-side API and business logic
- Front-end interface (Astro, HTMX)
- Authentication, deployment, and observability
What kinds of products do you build?
The typical shapes are operational: internal tools and admin systems, customer portals, quoting and pricing platforms, workflow and scheduling systems, mobile field apps, and the reporting interfaces on top of them. The common thread is software a business runs on — built as one coherent system, not a collection of parts.
- Internal tools and admin systems
- Customer portals
- Quoting and pricing platforms
- Workflow and scheduling systems
- Mobile field apps (iOS and Android)
- Reporting interfaces
Can you build cross-platform mobile apps for iOS and Android?
Yes. Cross-platform mobile development builds one codebase that runs natively on both iOS and Android. Revenant Systems builds cross-platform mobile apps with React Native and Expo, sharing data and business logic with the web back end so a single team ships the API, web app, and mobile app together.
- React Native and Expo
- Shared API and logic with the web app
- iOS and Android from one codebase
Which back-end stack does Revenant use?
Revenant Systems builds back ends in Go, Node.js, and Python, chosen per project rather than by default: Go for high-throughput services, Node.js for JavaScript-aligned teams and real-time features, and Python for data- and AI-heavy workloads. Front ends use Astro and HTMX for fast, lean, low-JavaScript interfaces.
| Technology | Role | Chosen for |
|---|---|---|
| Go | Back end | High-throughput services |
| Node.js | Back end | JavaScript-aligned teams and real-time features |
| Python | Back end | Data- and AI-heavy workloads |
| Astro + HTMX | Front end | Fast, lean, low-JavaScript interfaces |
| React Native + Expo | Mobile | iOS and Android from one codebase |
How are full-stack builds deployed?
Every Revenant Systems build ships with a working deployment path: continuous integration, environments, and hosting sized to the product — a managed platform where that is enough, infrastructure as code and Kubernetes where the workload justifies it. Deployment and handover are part of the engagement, not an extra.
- Continuous integration and delivery
- Managed platform or Kubernetes, matched to the workload
- Documentation and handover
What's included
- Architecture and data-model design
- API and back-end implementation
- Web front end (Astro / HTMX)
- Cross-platform mobile app (React Native / Expo)
- Deployment, CI, and handover
Stack Go · Node.js · Python · Astro · HTMX · React Native · Expo
Frequently asked questions
How does a full-stack build start?
With an audit. For a new build the audit covers the problem space and the riskiest technical assumptions; for an existing system it covers architecture, code, and data. The findings become a precise, agreed specification — scope, constraints, and edge cases pinned down before engineering begins — so the build starts from a shared definition of done.
Who actually does the work?
A small, senior, in-house team — no outsourcing and no junior hand-offs. One team owns the data model, API, interface, and deployment end to end, so context is never lost between specialists and the system stays coherent.
Can you add an AI feature to the build?
Yes. Most new builds now carry an AI feature, and Revenant Systems designs and ships it within the same engagement — model selection, agent and tool design, and the guardrails that keep outputs reliable in production. The AI consultancy service page covers the detail.
What happens after launch?
Delivery includes deployment, documentation, and the access your team needs to run and extend the system independently. Handover is part of the engagement, not an extra — the work is judged on holding up after the engagement ends, not just at launch.
Can you take over an existing application?
Yes — starting with an assessment rather than a promise. For an inherited or ailing system, the legacy system rescue assessment maps the risks and produces a stabilisation plan first; build work then follows the same audit-first sequence as any other engagement.
Why Astro and HTMX rather than a heavier front-end framework?
Because most applications don't need one. Astro and HTMX produce fast, lean, low-JavaScript interfaces that load quickly and stay simple to maintain. Where a product genuinely needs richer client-side behaviour, the stack is chosen per project rather than by default.
Do you work with startups as well as established companies?
Yes — Revenant Systems works with startups, growing companies, and established SMEs. For an early-stage product the audit stage is lighter: it validates the riskiest assumption, often as a rapid proof of concept, before the full build commits the budget.
Every engagement follows the same process — see how we work.