Oksa Satya.

Engineering notes

Technical notes from building production business systems — written from experience, not theory.

13 articles · payroll, POS, multi-tenant, Go, PostgreSQL

July 8, 2026 · 8 min read

Building an Auditable POS: Shifts, Cash Reconciliation, and QRIS

A cashier system is not about adding up prices. Here is how Dexova POS keeps the money matching: open/close shifts with opening cash, split payments, Midtrans QRIS, void & returns that restore stock, and daily cash reconciliation.

POS · Cashier · Reconciliation · Midtrans

July 2, 2026 · 7 min read

Geofenced Attendance: From Buddy-Punching to Check-ins You Can Trust

Manual attendance is easy to game. Here is how to build a PWA attendance system with nearest-office detection, a mandatory selfie, a two-address model for WFH, and approval-gated corrections — without imprisoning honest employees.

HRIS · Attendance · Geofence · PWA

June 12, 2026 · 7 min read

Multi-Tenant Isolation with PostgreSQL Row-Level Security (RLS)

Tenant filters in the application are easy to forget — and one slip leaks data. RLS moves isolation into the database as a last line of defense. Here is how to use it correctly, plus the leak tests you must have.

PostgreSQL · Multi-tenant · RLS · Security

May 28, 2026 · 7 min read

Stock That Doesn't Lie: Returns, Voids, and Multi-Warehouse

Inaccurate stock makes every report untrustworthy. Here are the principles that keep inventory honest: every stock change is a recorded event, returns put items back, and inter-warehouse movements are traceable.

Inventory · Stock · POS · Architecture