Technical Highlights & Architectural Focus

Architected enterprise distributed microservices powering fintech operations for thousands of active daily users

Engineered resilient payment orchestration workflows supporting multiple digital financial payment gateways

Database partitioning and index optimization yielding sub-50ms API response times under high concurrency

Containerized multi-service deployment with Docker, health probes, and automated failover recovery

Interface Screenshots & Platform Architecture

4 screens

SABIL Consumer Home — Real-time Account Balances, Fast Actions & Mini-App Grid

Instant QR Payment Engine — Fast Merchant Checkout & Transaction Authorization

Digital Wallet Management — Card Controls, Security Settings & Daily Limits

Multi-Channel Utilities & Bill Payments — Fast Settlements & Digital Receipts

SABIL Mega-App: Digital Payment & Financial Microservices

SABIL is a major Algerian digital payments and financial services mega-app operating at national scale. As a Senior Software Engineer at SABIL Company (04/2025 - 02/2026), Faycal Rafa was instrumental in designing, architecting, and optimizing the distributed microservices that power the consumer-facing mobile application and critical administrative back-office operations.

1. Enterprise Scale & Mission-Critical Responsibilities

The SABIL platform processes millions of transactional records annually across multiple payment categories including merchant QR code payments, utility bill collections, peer-to-peer transfers, and micro-insurance integrations:

Zero Downtime Mandate: Financial systems require continuous availability, stringent audit logging, and zero tolerance for balance reconciliation discrepancies.
Microservices Engineering: Faycal architected modular NestJS services communicating via asynchronous event channels and synchronous REST APIs, ensuring decoupled lifecycles between core ledger, payment gateway integration, and notification modules.

2. Key Architectural Contributions

2.1 Multi-Gateway Payment Orchestration

Designed a unified payment orchestration engine that abstracts third-party banking switches, regional cards, and mobile network operator payment rails into a coherent internal API contract.
Built automated retry with exponential backoff and idempotency key verification to guarantee that duplicate network submissions never cause double-charging under unstable cellular connectivity.

2.2 Database Partitioning & Extreme Throughput Tuning

Handled massive transaction history growth by implementing table range partitioning by date within PostgreSQL, keeping primary query indices hot in memory.
Optimized database execution plans, connection pool sizing with PgBouncer, and index structures, driving average end-to-end API response latency under 50ms even during month-end bill payment spikes.

2.3 DevOps & Containerized Resiliency

Structured containerized deployments using Docker and health check probes, facilitating zero-downtime rolling updates.
Integrated comprehensive distributed tracing and error telemetry to pinpoint upstream third-party gateway degradations before they impact end-user experience.

3. Product Availability & Links

Application Download: Available for Android and iOS devices at sabil.dz/en/getapp
Target Audience: Algerian consumers and commercial merchants nationwide
Role Duration: Senior Software Engineer (04/2025 – 02/2026)