03 · CST Goods-In · Real-Time Operations

Logistics ops: 80% faster workflows with real-time mobile app

Challenge: CST's front-desk and goods-in teams managed visitor, delivery, device, and notification workflows across disconnected systems. Solution: As senior full-stack contractor, I built a React Native/Expo app over FastAPI, Supabase, WebSockets, and HaloPSA integrations, with retries, token refresh, and real-time state. Outcome: workflow processing fell 80% and API response time improved from 500ms to 200ms. Next: Message me to map this to your operations.

Senior Full-Stack Developer (Contract)2024Shipped

Case study

What was built and why it mattered.

Outcome, ownership, architecture, and evidence in one view.

CST needed a reliable front-desk and goods-in system to replace fragmented visitor, delivery, pass, and device workflows. The challenge was to improve processing speed without creating another disconnected system for staff to maintain.

I built a mobile-first React Native application backed by FastAPI and Supabase, with WebSocket updates, HaloPSA integration, and notifications through Slack and SendGrid. The system centralised visitor check-in, pass availability, deliveries, purchase-order lookup, device intake, and exception handling.

The resulting workflow reduced processing time by 80%; a focused performance pass also improved API response time from 500ms to 200ms. It shows delivery across product workflows, backend services, live updates, integrations, and real-world operations.

One flow from the mobile app to business systems and staff alerts, with live updates and clear recovery steps.Solid = primary flow · dashed = support / control path

Download editable Excalidraw

MOBILE_OPERATIONS

React Native and Expo Router deliver quick reception workflows across phone, tablet, and web-ready surfaces.

REAL_TIME_STATE

WebSockets, heartbeats, reconnect behavior, and Redux state keep visitor and pass information current during active operations.

WORKFLOW_INTEGRATIONS

HaloPSA, Slack, SendGrid, Cloudinary, and FastAPI/Supabase services connect the mobile workflow to existing business systems.

MEASURABLE_DELIVERY

Processing time fell 80%, while backend and data-fetching changes brought API response time from 500ms to 200ms.

The problem

CST’s front-desk and goods-in teams were coordinating visitor check-in, passes, deliveries, purchase orders, device intake, and staff notifications across disconnected processes. That slowed down reception work, obscured what was happening on site, and created too much manual follow-up.

My role

As the senior full-stack contractor, I built the mobile application architecture and its service integrations. I focused on turning several time-sensitive workflows into one reliable, mobile-first operating surface while retaining the connections to the company’s existing systems.

The system

What I built

One workflow surface for busy teams

The application combines visitor and contractor check-in, live pass inventory, package registration, purchase-order search, unexpected deliveries, device check-in, and collection status. Staff do not have to move between separate systems to complete routine front-desk work.

Real-time information people can trust

The dashboard tracks current visitors, available passes, and operational activity through WebSocket connections. Heartbeats, reconnect behavior, refresh fallbacks, and centralized state management were included so the live view stays useful when the network is not perfect.

Integrations instead of another data island

HaloPSA, Slack, SendGrid, Cloudinary, and FastAPI/Supabase services connect the front-desk app to the workflows already used by the wider business. Visitors and deliveries can trigger the notifications that matter to staff, rather than adding another manual step.

A reliable mobile client

The React Native and Expo implementation uses TypeScript, Redux Toolkit, a centralized Axios layer, token refresh, retries, request IDs, and limited offline queueing for critical actions. Those details keep the feature screens fast and keep failure modes contained.

Results

Cut logistics workflow processing time by 80%.
Improved API response time from 500ms to 200ms through backend and data-fetching improvements.
Created one practical operations surface for reception, deliveries, passes, and device workflows.

Stack

React Native, Expo Router, TypeScript, Redux Toolkit, NativeWind, Gluestack UI.
FastAPI, Supabase, WebSockets, REST APIs.
HaloPSA, Slack, SendGrid, Cloudinary, and Apple Sign In.

What this case study proves

CST is evidence that I can take ownership beyond an AI layer: map real operational work, build reliable async services and integrations, ship a production-minded mobile experience, and measure the resulting improvement.