Blog
Project notes and guides to technology decisions, costs, and risks in business operations.
125 articles found
For Technical Teams
Database Indexes: Read Gains and Write Costs
Index write costs, composite column order, reading EXPLAIN without panic, why indexing every column is a smell.
For Technical Teams
IoT Billing Architecture: Meter Readings to Invoices
IoT billing architecture from meter readings to invoices: ingestion, aggregation, versioned tariffs, review, and a traceable audit trail.
For Business
AI Licenses: Check Code, Model Weights and Data
AI code licenses do not clear model weights or training data. Check each version before commercial deployment.
For Technical Teams
Payment API Idempotency: Avoiding Double Charges
Idempotency keys stop retried payment requests from double-charging customers. How Stripe, Adyen, Midtrans, and Xendit each implement them.
For Business
Open-Source Licenses in Commercial Software
MIT, Apache, LGPL, GPL, AGPL — what each license obligates in commercial software, and where teams get burned.
For Technical Teams
PostgreSQL GROUP BY Local Day Across Time Zones
Use PostgreSQL AT TIME ZONE to GROUP BY local day or hour across time zones, including half-hour offsets and daylight saving changes.
For Business
Adding WhatsApp Automation to Hotel Operations
Automate important hotel messages, track delivery and give staff a failure path. Check language, cost and guest consent.
For Technical Teams
Modbus Polling vs Event-Driven Ingestion in IoT Backends
Polled Modbus vs event-driven MQTT — how each works, when to use which, why connection health matters more for polling.
For Business
How to Prevent Hotel Overbooking: Inventory vs Physical Room Assignment
Prevent double sales with shared availability and concurrent-booking protection. Test unavailable rooms and cancellations.
For Technical Teams
Unifying Modbus, BLE and MQTT in One Backend
How to unify Modbus, BLE, and MQTT devices behind protocol adapters and a normalization layer that writes one common telemetry data model.
For Technical Teams
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.
For Technical Teams
MQTT vs WebSocket: When to Use Each for IoT
MQTT vs WebSocket for IoT — what each is for, why real systems use both, and how data flows from broker to dashboard.