Senior Backend Engineer

Wasiu Abiola.

Fintech & Banking Systems

I build payment infrastructure that handles millions of transactions daily. From core banking integrations to cross-border remittance platforms, I engineer systems that financial institutions trust.

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8
8+
Years of
experience
₦2B
Daily transaction
value
5+
Banks &
fintechs
150K
Transactions
per month
Available now — open to remote roles worldwide
01 /

About me

"I don't just write backend code. I engineer the financial plumbing that keeps banks running."

With over 8 years of experience across tier-1 Nigerian banks and fintech companies, I've become deeply specialised in the intersection of software engineering and regulated financial systems.

My work spans payment gateway integration at HydrogenPay, a NIP-to-NPS migration at Guaranty Trust Bank, a full microservices transformation at Suntrust Bank, and cross-border remittance architecture at Swapmoney, a UK-regulated fintech.

I'm drawn to high-stakes, high-throughput systems where reliability isn't optional. The kind of engineering where a bug costs real money and a good design keeps it safe.

01
Payment Gateway Engineering
Paystack, Interswitch, CyberSource — production integrations with OAuth2, idempotency keys, and retry logic
02
Core Banking & NIBSS
NIP/NPS infrastructure, inter-bank settlement, CBN-compliant payment systems at scale
03
Cross-Border Payments
FCA/AML/KYC compliant systems, multi-corridor remittance, distributed UK/Nigeria team delivery
04
Microservices & Event-Driven
Kafka, Redis, Docker, Kubernetes — migration from monolith to domain-split services
05
Technical Leadership
Code reviews, TDD adoption, mentoring engineers, architectural decisions under pressure
02 /

Where I've worked

Dec 2025
— Present

Lagos, Nigeria
Guaranty Trust Bank
Senior Backend Engineer
  • Led migration from legacy NIP to the new NIBSS NPS payment infrastructure
  • Built backend services for a new retail loan origination and disbursement product
  • Contributing to payment pipelines processing ₦2B+ daily at 99.95% uptime
  • Enforcing engineering standards through code reviews and API design governance
Current Contract
Aug 2023
— Nov 2025

Lagos · Remote
HydrogenPay
Senior Backend Engineer, Payment Gateway
  • Engineered Payment Gateway microservices handling ~150K transactions/month, improving scalability by 40%
  • Integrated Paystack, Interswitch, and CyberSource with OAuth2 and webhook retry logic — 99.9% confirmation reliability
  • Designed business and customer onboarding APIs and bulk payment links adopted by 200+ businesses
  • Cut API response time from ~800ms to under 300ms through Redis caching and async processing
Feb 2023
— Jul 2023

Remote
Swapmoney
Senior Backend Engineer
  • Built cross-border payment APIs for GBP/NGN remittance flows across multiple corridors
  • Implemented FCA-aligned AML screening and KYC verification flows
  • Reduced failed transactions by ~35% via Redis caching and idempotent retry strategies
Contract
Oct 2018
— Jan 2023

Lagos, Nigeria
Suntrust Bank
Senior Backend Engineer (promoted from Backend Engineer)
  • 4 years — became the go-to engineer for payment and core banking integration architecture
  • Architected full monolith-to-microservices migration over 18 months, reducing failures by ~15%
  • Designed payment APIs processing ~₦500M daily with zero duplicate disbursements
  • Implemented Kafka event streaming decoupling 4 downstream services, reducing processing time by 20%
  • Optimised SQL Server and Redis caching — 45% faster response times on key APIs
Jul 2017
— Sep 2018

Lagos, Nigeria
Sterling Bank
Backend Engineer — AltBank
  • Built backend services for AltBank, Sterling's digital-first product supporting ~250K users
  • Engineered payroll and tax computation engine — reduced manual errors by 80%
  • NIBSS interbank and SOAP/REST switching integrations for real-time settlement
03 /

Tech stack

Tools and technologies I use to build reliable, high-throughput financial systems at production scale.

Core
C# ASP.NET Core REST APIs Microservices Domain-Driven Design
Data & Messaging
Apache Kafka Redis MS SQL Server PostgreSQL MongoDB Entity Framework Dapper NHibernate
Infrastructure
Docker Kubernetes Azure CI/CD Git
Security & Compliance
OAuth2 / JWT AML / KYC FCA Standards CBN Compliance Encryption
04 /

Let's build together.

Open to remote contract and permanent roles with international fintech and banking companies worldwide. I respond within 24 hours.

✉
Email
wasiuabiola.dev@gmail.com
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in
LinkedIn
linkedin.com/in/wasiu-abiola
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GitHub
github.com/wasiuabiola
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