Portfolio · Banking Infrastructure

Cash Deposit Machine Switch

Turning a fleet of physical cash deposit machines into one centrally monitored, centrally managed network.

A switch platform built to connect a bank's entire fleet of Cash Deposit Machines (CDMs) into a single system — giving banks real-time visibility into machine health, centralized control over on-screen content, and a unified, auditable record of every deposit transaction across every branch.

The system was built to address a problem that grows with every machine a bank deploys: a CDM isn't just a device, it's a small, physically distributed piece of infrastructure — and a fleet of them, spread across branches, is only manageable if someone can see all of it, at once, from one place.

Key Capabilities

One platform for devices, transactions and operations.

Real-time monitoring across an entire CDM fleet — door, sentry, vault, printer and receipt status per machine.

Open APIs and webhooks for system event notifications and third-party integration.

Centralized transaction logging with automated photo extraction mapped to each transaction.

Remote content management — background images, advertisements and theming pushed to all machines from one dashboard.

End-to-end encryption and multilevel role-based access control.

DR-ready with live database backups and master-slave configuration.

Full audit trail on every data view, entry and modification.

Context

Why this system was needed.

Banks deploying CDMs as part of their self-service channel expansion face a problem that scales badly with success: every machine added to the fleet is another physical device that can jam, run low on cash, go offline or need attention — and every one of them is sitting in a different branch, unattended, often outside normal banking hours.

Without a centralized system, “is the CDM in Macquarie working right now?” is a question that requires someone physically checking, or waiting for a customer complaint. Machine status, deposit reconciliation and content updates all lived as separate, manual, branch-by-branch problems rather than something the bank could see and act on centrally.

At the same time, every CDM deposit is a financial transaction that needs the same rigor as any other channel — logged, traceable, tied to a customer and secured — while the CDM itself is a physical machine that needs its own operational monitoring layer on top of that.

The Challenge

The problem wasn't a dashboard.

The core challenge wasn't building a dashboard — it was building a switch that could sit between a distributed fleet of physical machines and the bank's systems, handling real-time device monitoring, transaction processing and remote content management as one coherent platform instead of three disconnected tools.

Monitor the fleet in real time

Monitor door, sentry, vault, printer and receipt state across every deployed CDM.

Proactive abnormal-state alerting

Alert the right people automatically when a machine entered an abnormal state without requiring manual polling.

Centralized transaction logging

Log every deposit transaction centrally, tied to the machine, customer and amount.

Transaction evidence mapping

Extract and map photos captured by the CDM to the correct transaction record.

Fleet-wide content management

Push background images, advertisements and themes remotely across the entire fleet.

Secure and resilient infrastructure

Support APIs, webhooks, 2FA, encryption, role-based access, audit trails, DSS compliance and disaster recovery.

Cash Deposit Machine switch architecture

In effect, the system needed to function less like a device dashboard and more like an operations and transaction switch, with monitoring, content management and financial logging all routed through it.

My Role

Architecture and platform development.

I was responsible for the architecture and development of the platform, with ownership spanning device monitoring, transaction logging, content management and security.

Designing the switch architecture connecting the CDM fleet to the bank's monitoring, transaction and content systems.

Building real-time device status monitoring across the fleet.

Designing the automated alerting system for abnormal machine states.

Building centralized transaction logging, including photo extraction and mapping.

Designing the open API and webhook layer for integration and event notification.

Building remote content management for backgrounds, advertisements and theming.

Implementing 2FA login, end-to-end encryption and multilevel role-based access.

Designing audit trails and DR architecture, including live backups and master-slave configuration.

Engineering Challenges

Where the complexity actually lived.

Challenge 01

Treating a distributed device fleet as one system

The core difficulty wasn't monitoring one machine — it was aggregating live status from every machine in a fleet spread across branches into one coherent real-time view without that view lagging behind what was actually happening on each device.

Challenge 02

Making alerting proactive instead of reactive

An abnormal state that only surfaces when a customer complains or an admin happens to check is already too late. The system had to recognize abnormal conditions and notify the right people immediately.

Challenge 03

Tying financial transactions to physical evidence

Photos captured during a deposit had to be reliably mapped to the correct transaction record, which meant keeping the transaction and content-capture pipelines tightly synchronized.

Challenge 04

Managing content across the fleet

Content distribution had to work as a genuine fleet-wide push mechanism with format and ratio validation so a bad upload could not break every CDM display simultaneously.

Challenge 05

Meeting financial-system security standards on physical infrastructure

The platform had to apply 2FA, end-to-end encryption, DSS compliance and full auditability consistently across monitoring, transaction processing and content management rather than treating security as something limited to financial records alone.

Reflection

Physical and financial infrastructure are often the same system.

This project changed how I think about systems that sit at the boundary between physical infrastructure and financial data. It's tempting to treat device monitoring and transaction processing as separate problems — one is operational, one is financial.

In practice, for something like a CDM, they're the same problem viewed from two angles: a machine going out of service and a deposit needing investigation both trace back to the same physical device, at the same branch, at the same moment. The real engineering work was building a switch that didn't force a choice between those views.