Samuel Nwabueze

Engineering core backend microservices for a UK-based escrow and marketplace platform using Fastify (Node.js/TypeScript). Architected an Azure Service Bus event-driven messaging backbone and delivered three critical microservices: ms-audit, ms-notifications, and ms-request-tracking — the compliance and observability backbone of the platform. Integrated Azure Cosmos DB and Redis caching across high-frequency endpoints.

Architected and delivered the full Cluster Management Lifecycle System in Java Spring Boot 3 — a five-step Cluster Creation Wizard with Stripe Billing integration, idempotent webhook processing and SLA-driven billing enforcement. Built enterprise LDAP integration for SSO, Keycloak OIDC auth across 15+ microservices on Kubernetes, and HashiCorp Vault-managed secrets. 85%+ test coverage across all production services.

Architected and built BoldPay — a production-grade microfinance core banking platform integrated with Apache Fineract: full loan lifecycle (application → disbursement → repayment → closure), KYC/KYB customer onboarding, settlement and reconciliation engine with idempotent transaction guarantees, and multi-tier RBAC. Also architected a B2B real-money gaming platform with WebSocket (STOMP) pipelines at sub-100ms P99 and a provably fair HMAC-SHA256 RNG.

Led the backend team for a production LPG delivery and payments platform serving 10,000+ active users. Architected the Synterium Engine — an immutable append-only payment ledger using cryptographic hash-chaining as the financial truth spine. Engineered a production-grade idempotency framework in NestJS, Paystack and Flutterwave webhook infrastructure with HMAC validation and dead-letter handling. Deployed on AWS (EC2, RDS, S3, CloudWatch) — 99.9% uptime sustained.

Developed production fintech backend microservices in Java Spring Boot and NestJS for a loan origination and servicing platform. Built secure financial APIs with JWT and OAuth2-based RBAC, implemented asynchronous message-driven processing with RabbitMQ, and collaborated in Agile squads applying circuit breakers, saga choreography and API gateway routing patterns.

Engineered a fiat-to-naira payment API with multi-stage fraud detection — velocity checks, duplicate fingerprinting and real-time risk scoring. Designed a scalable staking and monetisation engine. Integrated Sui Move smart contracts on-chain for wallet generation, player staking pools and tokenised asset management. Built Raspberry Pi-based real-world player authentication bridging physical device verification into the digital staking system.

Built and maintained RESTful API backends for financial and B2B SaaS platforms in Java Spring Boot and Express.js — establishing the Java foundation that underpins all subsequent roles. Implemented Redis caching and PostgreSQL query optimisation achieving ~35% latency reduction. Supported CI/CD pipeline setup and cloud deployments on AWS and DigitalOcean.