Operational Systems That Stay Reliable in Real Use
I’m Rayhan, an Indonesia-based software engineer. I help teams build backends, integrations, dashboards, and business systems for payments, device telemetry, facility workflows, and hotel operations.
5+
5+ Production Systems
3
3 Product Locales
5
5 Years Experience
8+
8+ Device Categories
Where I Can Help
Backends, APIs, integrations, and dashboards for teams that need reliable software after launch.
Backend Operational Systems
Build reliable web platforms from scratch — APIs, databases, dashboards, user roles, and operational workflows designed around your team's actual needs after deep analysis.
Fintech Workflow APIs
Help with payment orchestration, transfer lifecycles, ledger updates, reconciliation, idempotency, and status tracking when the domain matches my experience.
System Architecture Design
Plan maintainable architectures, data flows, integrations, and failure recovery for systems that need to stay dependable.
IoT Telemetry & Multi-Protocol Backends
Build ingestion across MQTT, WebSocket, Modbus, and BLE — device state caching, alerting, and dashboards tailored to how your operators actually work.
ERP-style Hotel Management Systems
Create booking engines, property management workflows, room status boards, guest records, invoices, staff salary, attendance tracking, reporting, and POS integrations.
Legacy Modernization & Technical Consulting
Review existing systems, modernize fragile flows, improve APIs, observability, deployment, and team handover when the work fits the systems I know.
Portfolio
Projects I’ve contributed to
Testimonials
Client notes and project outcomes
“Before this system, revenue, room status, and staff workflows were still spread across manual notes. After the HMS went live, daily operations became more organized, rooms were easier to track, and staff work became more structured.”
Hotel Owner
Owner, Hotel in Pekalongan
Project summary
Commissioned kiosk system for a physical photo booth: QRIS payment, template selection, camera capture, GIF output, printing, and QR-based customer downloads.
Photobox Kiosk Project
Project summary, Photobox, Gorontalo
Blog
Real stories from building fintech, IoT, integration, and hospitality systems