Projects & case studies

Problem

Products needed separate integrations for Orange Money, Wave, and Free Money — slow launches and inconsistent error handling across providers.

Solution

Unified SDK exposing one API for initiate, confirm, and reconcile flows — provider-specific adapters behind a stable contract.

Architecture

Adapter pattern with Spring Boot services, Redis idempotency keys, and Kafka events for async settlement notifications.

Security

Signed requests, webhook HMAC validation, and per-tenant API keys with scoped permissions.

Scale

Horizontally scaled stateless API; provider latency isolated via async queues without blocking client threads.

Problem

Financial products required auditable balances with strict consistency — spreadsheet-style tracking was not acceptable for compliance.

Solution

High-consistency ledger with double-entry postings, immutable audit log, and transactional guarantees on every money movement.

Architecture

PostgreSQL with serializable transactions for postings; append-only audit store; reconciliation jobs for provider drift.

Security

Role-based access, immutable audit trail, and no destructive updates on posted entries.

Scale

Partition-friendly schema and batch reconciliation for high-volume mobile-money corridors.

Problem

A bank and its partners needed one entry point to African payment providers without exposing fragile core systems.

Solution

Enterprise gateway centralizing auth, routing, rate limits, and provider orchestration behind versioned REST APIs.

Architecture

Spring Cloud Gateway + domain microservices; Kafka for domain events; Jasper/reporting decoupled from transactional path.

Security

JWT at edge, RBAC, input validation before core contact, full request audit logging.

Scale

Stateless gateway tier; Kafka absorbs analytics peaks without blocking payments.

Problem

Private schools ran disconnected admin, billing, and academic tools — no single operational source of truth.

Solution

Modern multi-tenant SaaS for admissions, billing, staff, and reporting — built for African school operations.

Architecture

Angular + Spring Boot REST; async jobs for bulk operations; modular domains per school tenant.

Security

Tenant isolation, encrypted sensitive records, role-based staff access.

Scale

Async processing for reports and notifications; shared platform serving growing school networks.