Ingestion Layer
MQTT + Device-Aware Topic Routing
We implement MQTT subscriber services for real-time telemetry intake with isolated topic prefixes, supporting gateway-based rollouts across multiple sites without data collision.
Our Story
A Hong Kong–based software engineering team with deep roots in capital works supervision — building the tools we once needed ourselves.
Why We Built DWSS
Hong Kong's capital works sector has long relied on paper-based supervision forms — RISC booklets, G.F. 527 Labour Returns, G.F. 536 Site Diaries — all manually stamped, physically circulated, and filed in ring binders.
DEVB's TC(W) No. 8/2025 marks a turning point: every capital works contract tendered from 1 April 2026 must use a DWSS. We built ours because we understood the domain from the inside — the three-party routing of RISC forms, the nuance of WBTC 19/93 file references, the mandatory SSSS CMP amalgamation — and we knew most generic document management systems would not be fit-for-purpose.
The result is a system designed for Site Inspectors, Resident Engineers, and Project Managers — not generic office workers. Every workflow mirrors the actual approval chain on a HK Government works contract.
Every data model maps directly to a TC(W) 8/2025 clause. Compliance is structural, not a checklist applied post-hoc.
MFA mandatory, 12-char passwords, 5-attempt lockout, 30-min idle timeout, append-only audit trail — all defaults, not options.
Built for GCC and NEC contracts, HK80 coordinates, Cantonese/English bilingual UI, and local government workflows.
Technology Stack
No proprietary lock-in. The full stack is open source, containerised, and deployable on any cloud provider.
Full RESTful API layer for iCWP DSR export, mobile clients, and SSSS vendor ingest endpoints.
Full-text search via SearchVector, JSONB for telemetry metadata, and transactional integrity for all workflow state transitions.
Async task queue for email/notification dispatch, iCWP XML export jobs, and scheduled report generation.
Hypermedia-driven partial page updates — no complex SPA framework, yet a seamless single-page feel for all forms.
Lightweight reactive behaviour for dropdowns, toggles, and conditionally-shown form fields without a build step.
Utility-first CSS framework. Consistent design system across 80+ templates with a bespoke navy + teal palette.
Our Values
Every feature decision starts with the relevant TC(W) clause. We never ship a workaround when the regulation requires a specific behaviour.
HKSARG security standards are defaults, not optional add-ons. MFA, lockout, audit trails, and session controls ship out of the box.
Built for Site Inspectors working in the field on mobile — not office administrators. Minimal taps, offline-tolerant, bilingual.
HK80 coordinates, GCC and NEC contract types, Cantonese Traditional Chinese UI, local government procurement conventions.
IoT Systems Engineering
Beyond document workflows, our team designs and delivers production IoT platforms. We build secure data pipelines that ingest telemetry from field devices, structure it into queryable history, and expose it through operational dashboards and APIs.
We implement MQTT subscriber services for real-time telemetry intake with isolated topic prefixes, supporting gateway-based rollouts across multiple sites without data collision.
We provide broker-side authentication webhooks that validate device identity and tokens before allowing publish rights, so only approved and active devices can write into the platform.
Our data model uses Device, SensorType, and TelemetryData entities to normalize mixed sensor streams. We then expose history APIs for trend charts, anomaly checks, and reporting.
What We Deliver for IoT Projects
Onboarding, token issuance, activation/deactivation, and visibility of device health status across deployments.
Reliable ingestion for live monitoring plus query endpoints for per-device trend lines over configurable time windows.
Background jobs for alerts, batch exports, and scheduled summaries using queue-based workers for stable operations at scale.
REST interfaces for external systems, mobile clients, and data exchange workflows so your platform can evolve without lock-in.