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03 / Confidential System

Fuel Custody & Reconciliation Platform

A full-stack fuel governance platform for tracking, authorizing, reconciling, and auditing fuel movement across stations, tanks, pumps, vehicles, tanker deliveries, and field devices.

ConfidentialPetroleum Digital Operating SystemMulti-tenant SaaSOffline-first field operations

Django · PostgreSQL · Redis · React · Next.js · TypeScript · Docker

Figure 01Fuel Custody Operating Map
Fuel Custody Operating Map mobile viewStacked representative map showing field layer, control and event layer, and governance layer.FIELD LAYERFuel PumpsATG TanksRFID / PlateTanker SensorsCONTROL + EVENT LAYEREdge ControllerOffline QueueAuthorizationIngest + NormalizeFuel Event StoreAudit TrailGOVERNANCE LAYERReconciliationAnomaly AlertsReportsDashboard

Figure 01 — Representative operating map showing field devices, edge control, fuel events, reconciliation, alerts, reports, and audit evidence.

01 / Product Context

What the product is

A multi-tenant operational platform that governs fuel movement across the supply chain — from depot loading and tanker transport to station delivery, dispensing, authorization, and reconciliation.

02 / Operational Problem

Why it matters

Fuel losses, unauthorized dispensing, weak traceability, and manual reconciliation create financial leakage and compliance risk. The system brings every liter into a traceable, reviewable, and auditable workflow.

03 / Contribution Scope

My role

Contributed as a software engineer across backend and frontend modules within a larger product team, supporting API-connected workflows, event visibility, reconciliation/reporting flows, authentication, and operational dashboard behavior.

02 / Domain Flow

Fuel movement lifecycle

Fuel custody starts before the station transaction. The system models the lifecycle from loading and transport through delivery, tank movement, pump dispensing, vehicle authorization, and final reconciliation. This makes fuel movement itself traceable, not only the location of a truck or a manual station report.

02 / Domain FlowFuel movement lifecycle
Fuel movement lifecycle mobile viewVertical lifecycle showing how fuel movement becomes auditable evidence.Every liter becomes an auditable event01Depot Loadingvolume event02Tanker Transportgeo-tagged route03Station Deliverydelivery event04Tank IncreaseATG tank delta05Pump Dispensingpump transaction06Vehicle Auth.RFID / plate07Reconciliationaudit recordeventsignalaudit

Figure 02 — Fuel movement lifecycle from loading to final audit record.

03 / Rules Engine

Reconciliation logic

Reconciliation compares independent signals instead of trusting a single source. Delivery volume is compared against actual tank increase, pump dispensing is compared against tank decrease, and fleet transactions are checked against vehicle authorization and policy limits.

03 / Rules EngineReconciliation logic

Reconciliation model

The platform does not trust one source of truth. It compares independent records from field devices, tanks, pumps, vehicles, and delivery events. When those records do not match, the system produces an operational output for review, reporting, or audit.

01 / Rule model

Delivery reconciliation

Check

Tanker delivery vs station tank receiving

Compares the delivery volume reported by the tanker against the actual increase recorded by the station tank system. If the difference is outside the allowed tolerance, the system surfaces it as an investigation item.

Evidence compared

Evidence source

Reported tanker delivery

Delivery volume from tanker record

Compared with

Evidence source

Actual tank increase

Tank-level change from ATG reading

Output

Variance alert / investigation record

Used by operators to review delivery mismatch

02 / Rule model

Station reconciliation

Check

Pump dispensing vs tank movement

Compares the volume dispensed by pumps against the expected decrease in tank level. This helps detect shrinkage, meter mismatch, leakage, manual reporting gaps, or suspicious station activity.

Evidence compared

Evidence source

Pump dispensed volume

Pump transaction / totalizer reading

Compared with

Evidence source

Tank level decrease

Expected tank movement from ATG

Output

Daily reconciliation report

Used for station review and operational reporting

03 / Rule model

Fleet authorization

Check

Vehicle identity vs fueling policy

Checks whether the vehicle identity and fueling transaction match the allowed fleet policy. This helps prevent unauthorized fueling, card misuse, and uncontrolled fleet consumption.

Evidence compared

Evidence source

Vehicle identity

RFID tag / license-plate recognition

Compared with

Evidence source

Fueling transaction

Pump event linked to vehicle

Output

Fleet fuel record / policy exception

Used for fleet consumption and audit history

Figure 03 — Independent signals are compared instead of trusting a single source.

04 / Reliability Model

Offline-first authorization

Fuel operations cannot depend on perfect connectivity. The edge layer supports local policy checks, queues events during interruptions, and synchronizes them back into the central audit trail when connectivity returns.

04 / Reliability ModelOffline-first authorization
Offline-first authorization mobile viewStacked decision flow for online cloud authorization and offline local policy checks.Offline-first authorization flowFueling Requestvehicle + pump + stationConnectionavailable?YES / Online pathCloud Authorizationcentral validationWrite Eventcentral event logDashboard Updateoperator visibilityNO / Offline pathLocal Policy Checkedge rulesQueue Edge Eventstore locallyRetry Syncwhen onlineMerge Audit Trailcentral evidenceNo silent data loss · Audit continuity

Figure 04 — Local authorization and queueing preserve operational continuity and audit evidence.

Technical Contribution Evidence

System contribution areas

01

Backend workflows

API-connected flows for fuel authorization, OTP authentication, RFID/license-plate integration, loyalty/wallet behavior, and reconciliation-related workflows.

APIs / Auth / Integration

02

Authorization and identity

Vehicle and user identity flows support controlled fueling, policy checks, and traceable transaction records across field operations.

RFID / Plate / Policy

03

Reconciliation and reporting

Rules-driven comparison of delivery, tank, pump, and fleet signals helps surface mismatches, exceptions, and operational reports.

Rules / Reports

04

Event visibility

Fuel events are treated as auditable records with device source, station context, vehicle identity, timestamps, and reconciliation status.

Events / Audit

05

Offline-first reliability

Edge-side buffering and local authorization thinking supports continued station operations during connectivity interruptions.

Edge / Sync / Resilience

06

Operational dashboards

Dashboard and reporting views translate raw field activity into exceptions, compliance records, KPIs, and management visibility.

Dashboards / UX

Technical Environment

Stack used across the product environment.

DjangoPostgreSQLRedisReactNext.jsTypeScriptDockerEvent Sourcing

What this project demonstrates

This project demonstrates operational software engineering: systems where reliability, traceability, authorization, and domain rules matter as much as the interface. The value is not the screen alone; it is the system’s ability to turn field activity into trusted operational evidence.