Nwaoke Francis Chizaram

Chizaram Nwaoke Lagos Nigeria | - |- Objective Systems-driven Backend Engineer with 4+ years designing, architecting, and scaling real-time, transactional platforms across fintech, healthtech, e-commerce, and logistics. I specialize in building resilient, secure, and performant services using Node.js, TypeScript, PostgreSQL, and event-driven architecture. Proven track record of shipping mission-critical products that serve 100K+ users, maintain 99.9% uptime, and integrate complex workflows across domains. I don't just build APIs. I engineer ecosystems that power digital businesses. Technical Skills Languages: TypeScript, JavaScript (ES6+), Python, SQL, Infrastructure: AWS (EC2, RDS, S3, CloudWatch), Docker, Bash Docker Compose, GitHub Actions, GitLab CI/CD Back-End: Node.js, Express, NestJS, Fastify, GraphQL, Traffic & Scaling: Redis, RabbitMQ, Load Balancers, CDN gRPC, WebSocket Caching, Rate Limiting Architecture: Microservices, Modular Monolith, Event- Monitoring & Observability: Prometheus, Grafana, ELK Driven Systems, Fault Tolerance, High Availability, Clean Stack, Sentry, Winston Architecture, SOLID Testing: Jest, Mocha, Supertest, Postman Database Engineering: PostgreSQL, MongoDB, MySQL, Query optimization, indexing, sharding, ACID compliance Professional Experience BACKEND ENGINEER /LEAD SYSTEM ARCHITECT | 10/2023 - Current JAYCOLINK - Lagos, Nigeria RendezvousCare (Dating & Wellness Platform) Designed a fault-tolerant backend with modular monolith architecture and horizontally scalable infrastructure deployed on Dockerized AWS. Managed large-scale user data and activity logs using optimized PostgreSQL queries, Redis caching, and API pagination strategies. Built data-heavy endpoints behind an API gateway for traffic routing, authentication, and usage throttling. Applied rate limiting, robust input sanitization, and secure authentication middleware with role-based access control. Architected ACID-compliant transactional flows for wallet and booking modules. Built real-time chat and video systems using WebSockets, with load shedding, reconnection logic, and session persistence. Set up centralized logging and real-time monitoring using Prometheus, Grafana, and Sentry for visibility and debugging. Collaborated closely with frontend engineers and product managers to align API design with user experience and product goals. Impact: Served 50K+ daily users with 99.95% uptime and low-latency performance across high-volume data endpoints. VTB (Real-Time Logistics Booking System) Engineered an event-driven booking engine using Redis pub/sub and RabbitMQ to process high-volume logistics events. Managed delivery tracking and booking datasets through batch writes, read-optimized DB indexing, and pagination. Applied PostgreSQL query optimization (indexing, isolation levels) and ACID compliance for data integrity. Routed all service requests via a centralized API gateway for scalable traffic management and secure token handling. Integrated rate limiting, circuit breakers, and NGINX-based traffic control with robust input validation and sanitation. Implemented secure token authentication and user session management. Deployed audit logging, system health dashboards, and error alerting using ELK Stack and Prometheus. Worked collaboratively with the frontend team and product leads to shape booking logic, tracking UX, and system behavior. Impact: Achieved 99.98% uptime, seamlessly handled thousands of concurrent booking requests and real-time updates. Payrendr (HR & Payroll System) Built a resilient salary computation engine using scheduled cron jobs and PostgreSQL optimization (indexing, isolation, rollback protection). Managed salary histories and payroll data storage efficiently with bulk writes and query filtering strategies. Integrated RabbitMQ-based recovery workflows for failed external bank API calls, with retry queues and logging. Used API gateway to enforce rate limits, log request metadata, and manage secure access tokens. Enforced rate limiting, user input sanitation, and OAuth-secured endpoints. Applied multi-step financial workflows with transaction consistency and atomicity. Enabled detailed audit logging, real-time alerting, and monitoring with Grafana, ELK Stack, and Winston. Participated in cross-functional planning with product managers and UI/UX to ensure alignment of business logic and user workflows. Impact: Automated 95% of payroll tasks with secure, observable operations for high-volume financial data. Jerify (AI-Powered KYC Platform) Developed secure microservices for biometric KYC using TensorFlow, facial recognition APIs, and encrypted data flows. Handled high-throughput biometric submissions and verification logs using asynchronous queues and write-heavy DB optimizations. Built distributed retry queues, degraded-mode fallback systems, and load-balancing logic for high availability. Applied PostgreSQL tuning, query indexing, and consistent schema validations for optimized storage. Added strict sanitization, rate limiting, and token-based access controls to all endpoints. Centralized routing and logging through API gateway for analytics, load handling, and request authentication. Monitored system health, ML inference, and error rates with Prometheus + Grafana dashboards. Worked with frontend devs and product managers to streamline identity flows and system interactions. Impact: Enabled 80% automation in KYC verifications; processed and served 100K+ monthly sessions reliably. BACKEND ENGINER /LEAD SYSTEM ARCHITECT | 01/2023 - 10/2023 MOTHER UNICORN - Lagos, Nigeria E-commerce Microservice Platform Built containerized microservices for cart, order, checkout, and payments using RabbitMQ event queues. Managed large catalog and transaction datasets with partitioned PostgreSQL tables and Redis query caching. Applied robust token-based authentication, input sanitization, and per-route rate limiting. Used API gateway to route requests securely, monitor usage, and enforce policy-based access control. Configured centralized logs and alerts via ELK and Grafana for SLA enforcement and system health. Collaborated with frontend engineers and product stakeholders to ensure seamless cart and checkout experiences. Impact: Scaled reliably to support 10K+ concurrent users with secure, efficient handling of product and order data. Receipt Scanner Rewards App Developed OCR pipelines with TensorFlow and async job queues, using containerized auto-scaling workers. Handled image data and reward claims in MongoDB with proper indexing, batch operations, and memory optimization. Used rate limiting, request validation, and token-auth via API gateway for secure interaction with third-party APIs. Applied secure data flows, payload sanitation, and log collection with Prometheus and Grafana. Coordinated feature integration and feedback cycles with frontend developers and product owners. Impact: Increased OCR throughput by 3x while maintaining 99.9% processing accuracy on image-heavy workloads. SOFTWARE DEVELOPER | 01/2021 - 12/2022 free lance Nurse Booking Platform Built real-time, geo-aware nurse-client matchmaking using PostgreSQL geospatial indexing and Redis pub/sub. Managed search and location datasets with geo-optimized queries and paginated result sets. Applied rate limiting, secure JWT authentication, and strict input sanitation. Centralized service communication through API gateway for scalable access control and real-time analytics. Enabled observability with Winston logs, Prometheus metrics, and error tracking via Sentry. Collaborated remotely with frontend devs and project managers to implement end-to-end booking features. Impact: Delivered 5K+ bookings for 10K+ users with Education Federal University of Petroleum Resources (FUPRE) - Effurun, Nigeria | B.Eng. Petroleum Engineering, 02/2019 Websites, Portfolios, Profiles https://francis-port25.vercel.app https://github.com/beardgod7 https://www.linkedin.com/in/nwaoke-francis-8904b0158?utm_source=share&utm_campaign=share_via& utm_content=profile&utm_medium=android_app Project Highlights erify (KYC AI Platform) → 100K+ verifications/month, ML pipelines with retry/resilience Payrendr (Payroll) → ACID-safe salary engine, recovery queues, finance integrations RendezvousCare → Video/AI matchmaking, 50K+ DAUs, multi-tenant scaling VTB Logistics → Real-time Redis-powered booking, 99.98% uptime, horizontal scaling E-commerce Microservices → ELK monitoring, rate limiting, sharding, retry fallbacks Nurse App → Geo-matching + WebSocket, low latency, high engagement platform References References available upon request.