Looking for a job

Celestine Njoku

@celestinenjoku

Message

I build secure backend APIs, payment integrations, and reliable platform services for fintech and web applications.

Nigeria

Message

What I'm looking for

I'm looking to build secure, reliable backend platforms and APIs, with ownership of server-side logic, data models, integrations, performance, and trust-sensitive workflows.

I've led backend delivery for fintech web platforms, APIs, and mobile integrations at Waza Fintech Co., while designing financial and operational workflows that support user-facing products.

Across Flagler Technologies, Nomba Financial Technologies, and Yelocode Systems, I've built secure APIs, payment integrations, database-backed applications, and authentication systems. I focus on dependable server-side logic, database performance, encryption, validation, and resolving integration failures before they affect users.

Experience

Work history, roles, and key accomplishments

Backend Developer

Waza Fintech Co.

Oct 2024 - Jul 2026 (1 year 9 months)

Led backend delivery across scalable web platforms, APIs, and mobile application integrations in a fintech environment. Designed application endpoints and data flows supporting user-facing financial and operational workflows.

NodeJS ExpressJS REST APIs MongoDB Prisma API Design Integration Fintech

API Backend Engineer / Cryptography Systems Developer

Flagler Technologies

Sep 2024 - Dec 2025 (1 year 3 months)

Designed, developed, and maintained scalable backend services and secure APIs supporting high-performance web applications. Developed a personalized encryption approach for server and database protection, applying security fundamentals to sensitive application data.

API Development Backend Services Database Integration Encryption Security Performance Optimization Debugging

Senior Backend Developer

Nomba Financial Technologies

Oct 2023 - Aug 2024 (10 months)

Managed company databases and web servers, taking responsibility for availability, data integrity, troubleshooting, and routine maintenance. Built secure web applications and API integrations for customer solutions, translating business requirements into backend workflows.

Database Management Web Server Administration API Integration Security Troubleshooting Backend Development

Junior Backend Developer

Yelocode Systems

Aug 2022 - Jun 2023 (10 months)

Built payment gateway integrations for client websites and mobile applications, supporting reliable transaction initiation and user flows. Collaborated with frontend developers to deliver dynamic websites and software while maintaining clear client-server integration boundaries.

Payment Gateway Integration NodeJS ExpressJS API Development Debugging Collaboration