Tunas Akara

Blog

Real stories from building fintech, IoT, integration, and hospitality systems

2026-06-2411 min read

Grouping Multi-Timezone Data in PostgreSQL Without Getting It Wrong

Grouping events by local day or hour in PostgreSQL breaks on half-hour zones and DST. The tested pattern that keeps multi-timezone dashboards correct.

postgresqltimezonedashboard
2026-06-236 min read

Adding WhatsApp Automation to Hotel Operations

Use WhatsApp as an operational layer for hotels — confirmations, reminders, room-ready messages, and staff alerts, each tied to a business event.

hotel managementwhatsappautomation
2026-06-226 min read

Modbus Polling vs Event-Driven Ingestion in IoT Backends

Polled Modbus vs event-driven MQTT ingestion — how each works, when to use which, and why connection health matters more for polling.

iotmodbusmqtt
2026-06-216 min read

How to Prevent Hotel Overbooking: Inventory vs Physical Room Assignment

Prevent hotel overbooking by separating room-type inventory from physical room assignment, with database constraints and short-lived reservation locks.

hotel managementoverbookingdatabase
2026-06-206 min read

Unifying Multi-Protocol Devices (Modbus, BLE, MQTT) into One Backend

How to unify Modbus, BLE, and MQTT devices behind protocol adapters and a normalization layer that writes one common telemetry data model.

iotmodbusble
2026-06-196 min read

Modeling Hotel Room Status as a State Machine

Why hotel rooms need a status state machine — clean, dirty, inspected, maintenance, ready — so housekeeping and front desk never collide.

hotel managementstate machinepostgresql
2026-06-186 min read

MQTT vs WebSocket for Real-Time IoT: When to Use Each

MQTT vs WebSocket for IoT — what each is for, why real systems use both, and how device data flows from broker to dashboard in real time.

iotmqttwebsocket
2026-06-179 min read

Hotel Management System: A Complete Guide for Independent Hotels

A complete guide to hotel management systems (PMS) for independent hotels: room status, bookings, overbooking, staff, and WhatsApp automation.

hotel managementpmshospitality
2026-06-169 min read

A Complete Guide to IoT Backends: MQTT, WebSocket, and Multi-Protocol Telemetry

A complete guide to IoT backends: ingesting MQTT, WebSocket, Modbus, and BLE telemetry and normalizing it into one real-time data model.

iotmqttwebsocket
2026-06-157 min read

Building a Hotel Management System for a Real Hotel

A practical story from building a hotel management system in Pekalongan with Next.js 16, Drizzle ORM, PostgreSQL, room state machines, and WhatsApp automation.

hotel managementnextjspostgresql
2026-06-156 min read

Building Dashboards That Connect Different Systems

A practical story about connecting system control, visitor management, and operational signals into dashboards teams can trust.

dashboardintegrationoperations
2026-06-157 min read

Freelance MQTT and WebSocket Backends for Real-Time IoT

A real freelance IoT story about MQTT telemetry ingestion, live WebSocket dashboards, nurse call systems, PLC integration, and multi-brand control systems.

iotmqttwebsocket