Integration & API Design
Multi-provider abstractions, webhook delivery, idempotent flows.
BACKEND ENGINEER
Backend engineer with 5+ years building production-grade financial systems across fintech, banking, and enterprise platforms. I specialise in payment processing, wallet infrastructure, distributed systems, and multi-provider integrations using Node.js, TypeScript, C#, and .NET.
5+
Years Experience
10K+
Users Served
5+
Payment Providers
Distributed Systems
Queue-based processing, event-driven architecture, concurrent job pipelines.
01.
About Me
I'm a backend engineer with over five years of experience building secure, scalable, and reliable systems in fintech, banking, and data-driven platforms. My work sits at the intersection of complex transaction processing, distributed systems, and real-world business problems where correctness, performance, and trust matter.
Over the years, I've designed and shipped wallet infrastructures, virtual accounts, payment pipelines, ledger-based systems, and analytics platforms used in production environments handling high transaction volumes. I have hands-on experience with Node.js, TypeScript, C#, ASP.NET Core, SQL-based systems, and cloud platforms like AWS and Azure. I'm especially comfortable working on mission-critical financial systems where idempotency, reconciliation, auditability, and failure handling are non-negotiable.
I've built deep expertise in event-driven architectures, queue-based processing, and provider-agnostic integration layers that abstract cleanly across heterogeneous systems. I'm comfortable owning the full backend lifecycle from system design through production, with a strong focus on correctness, idempotency, and reliability where every transaction counts.
I care deeply about clean architecture and developer productivity. I've migrated monoliths to microservices, optimized database performance with advanced SQL and stored procedures, set up CI/CD pipelines, and built internal tools that make teams faster and systems more reliable.
I'm driven by impact, clarity, and continuous improvement. Whether it's fintech, marketplaces, or data-heavy platforms, I enjoy solving hard backend problems and building systems people can trust.
Technologies I work with
- TypeScript
- JavaScript (ES6+)
- C#
- SQL
- Node.js
- Express.js
- NestJS
- ASP.NET Core
- .NET
- Entity Framework Core
- Hangfire
- React
- Redux
- HTML5
- CSS3
- Tailwind CSS
- SQL Server
- MySQL
- PostgreSQL
- MongoDB
- AWS (EC2)
- Azure (VMs)
- GitHub Actions
- RabbitMQ
- BullMQ
- Fastify
- Docker
02.
Experience
Lead Backend Engineer · Trade Treegar
- Engineered a greenfield virtual accounts platform (ASP.NET Core, PostgreSQL) from zero to production, supporting KYC verification, role-based admin workflows, and 1000 business accounts at launch.
- Designed ledger-based transaction flows for wallet funding, P2P transfers, and payouts with balance updates, histories, idempotency checks, and webhook reconciliation.
- Built a configurable inflow fee engine with global and per-customer percentage fees, caps, audit trails, and product-mapped fee transactions.
- Implemented safe transaction reversals with schema changes, stored procedures, audit logging, and secured API endpoints.
- Delivered a payout pipeline with queue-based approval rules, duplicate transaction guards, and provider routing — reducing failed payouts by 90% across 1000 daily transactions.
- Built a distributed background job processing system (Hangfire, SQL Server) with atomic job claiming, exponential backoff, and batch throttling across 5 concurrent financial pipelines — cutting failed job rates by 70%.
- Engineered a compound interest accrual engine with exactly-once write semantics and concurrent execution guards, eliminating duplicate payouts across 2000 active wallet accounts.
- Built a scheduled and recurring payment processor supporting one-time, weekly, and monthly schedules for P2P and external payout flows, with per-attempt idempotency keys and distributed execution locking.
- Designed a multi-provider payment abstraction layer (Polaris, VFD) using the Strategy pattern with a runtime ProviderResolver, enabling seamless provider switching per tenant without modifying core business logic.
- Architected a webhook delivery system with HMAC-SHA256 payload signing, retry scheduling, and idempotency tracking — achieving 90% reliable event delivery to 100+ customer-configured endpoints.
Lead Backend Engineer · Atunlo
- Designed backend architecture with secure role-based authentication and sessions.
- Architected a greenfield field-operations backend from zero to production, delivering REST APIs for staff management, agent onboarding, collections, and payments supporting 150 active agents across 22 regions.
- Built analytics pipelines powering real-time dashboards for agent performance ranking, disbursement tracking, and retail metrics — reducing reporting turnaround from 2 hours to minutes.
- Developed dynamic filtering across date ranges, staff, agents, materials, and reporting periods.
- Engineered a collection logging backend with auto-calculated amounts due, prepayment handling, multi-material support, and image verification — processing 350 collections per day at 90% accuracy.
Software Engineer (IC to Lead) · PennyTree
- Built and maintained a financial operations dashboard using React and C#, improving support efficiency and reconciliation accuracy.
- Migrated monolithic services into scalable microservices using Node.js and .NET.
- Reduced query latency by 65% by migrating monolithic services to Node.js microservices and optimizing SQL Server stored procedures, indexing strategies, and query plans.
- Improved payment success rates from 50% to 80% by integrating 5 payment gateway providers and building idempotent reconciliation flows for high-volume merchant and consumer transactions.
- Built a messaging and notification service (Node.js, RabbitMQ) handling email and push for 10,000+ users with 250ms average delivery time.
- Established CI/CD pipelines with GitHub Actions; delivered a bank transfer module and Slack monitoring for gateway uptime.
- Designed and implemented a full multi-currency investment lifecycle system supporting fixed-term vaults (30–360 days) and unit-based marketplace investments, with configurable interest rates, daily accrual, top-ups, and auto-renewal at maturity.
- Built partial and full liquidation flows with early withdrawal penalty logic, configurable fee caps, principal/interest separation, and multi-currency wallet crediting.
- Deployed a Slack monitoring bot tracking payment gateway uptime and anomalies across 10 providers, reducing MTTD by 70%.
Backend Engineer · IVantage Technologies
- Built and maintained a versioned Internet Banking REST API (Fastify, TypeScript) integrated with Datalinks core banking, handling account lookups, beneficiary management, and high-volume transfers for 3000+ daily active users.
- Improved transaction pipeline throughput by 70% by refactoring the core transfer flow with concurrency controls, idempotency keys, and optimized query patterns.
- Delivered a construction marketplace backend (BuildConnect) end-to-end — authentication, project milestones, bidding, and contractor verification — from architecture to production in 6 weeks.
- Delivered media handling with Cloudinary presigned uploads and verification workflows.
- Added scheduling features, lookup data management, OpenAPI docs, and Docker Compose tooling.
Lead Backend Engineer (Contract) · The Ajo App
- Architected savings, wallet, and P2P APIs using Node.js, Azure, MySQL, and Firebase.
- Collaborated with founders on product scope, timelines, and delivery strategy.
- Engineered a secure transaction platform with strict validation and idempotent flows.
- Integrated Stripe payment intents and webhook automation, increasing payment success rate to 99% and eliminating manual reconciliation across 4000+ monthly transactions.
- Architected savings, wallet, and P2P transaction APIs (Node.js, Azure, MySQL) from greenfield to production, onboarding 40 users within 2 weeks of launch.
- Engineered a template-driven challenge savings module with recurring debit automation, failed-payment retry logic, and end-of-cycle payout scheduling — achieving 80% on-time payout rate.
Lead Backend Engineer (Contract) · Monzone Credit Limited
- Built backend REST APIs for wallets, savings, P2P transfers, bill payments, and virtual cards.
- Integrated banking and payments providers (Providus, VFD, Wema, Paystack, Flutterwave) for account creation, payouts, funding webhooks, and bill validation.
- Built a USD virtual card lifecycle (Passpoint) with issuance, activation, wallet-fee funding, and freeze/unfreeze — enabling 200+ cardholders to transact globally from launch.
- Automated savings operations, interest accrual, vault maturity, schedules, wallet and card debits, failed debit handling, and referral payouts via cron jobs.
- Implemented RabbitMQ background processing workers for payouts, bill processing, reversals, and notifications — cutting async job failure rate by 60% versus the prior polling approach.
- Automated KYC and business verification workflows (BVN/NIN/RC via SeamFix/Smile Identity), reducing manual review time by 70% and cutting onboarding to under 5 minutes.
- Automated operations with Slack bots for payment alerts, payouts, and customer requests.
Full-Stack Engineer · Dufana Code Camp
- Co-built an enterprise facility management platform enabling residents to handle transactions via a mobile app.
- Built an admin dashboard for real-time data visualisation and reconciliation.
- Developed user interfaces with React and Tailwind CSS for dashboards and analytics tools.
03.
Selected Projects
Most of my production work lives on private company repositories. The projects below are personal builds, each backed by a Node.js or Express API, demonstrating the backend fundamentals that underpin the systems I build professionally.
04.
Education
B.Eng. Electrical & Computer Engineering
Software Architecture & Design of Large Scale Systems
05.
Get In Touch
I’m always open to collaborating on new projects or talking through ideas. Whether you’re building something new or need help scaling what you already have, feel free to reach out.
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