I'm a Backend-Focused Full-Stack Developer passionate about building scalable, secure, and API-driven systems that power real-world products.
My expertise lies in designing backend architectures, integrating multi-provider APIs, and deploying cloud services — from authentication layers and cron jobs to payment systems and real-time communication workflows.
With a strong background in cybersecurity and a hands-on approach to cloud infrastructure, I aim to deliver backend solutions that are reliable, fault-tolerant, and globally scalable.
Backend: Node.js, Express.js, Prisma ORM, PostgreSQL, RESTful APIs
Cloud & DevOps: AWS Cognito, Vercel, GitHub Actions, Cron Jobs
Frontend: React.js, Next.js, TailwindCSS
Payments & APIs: Yo! Payments, SWIFT Integration, Resend, OpenStreetMap
Other: Docker (basic), Git/GitHub, Web Security, Network Fundamentals
- WellaPath: Backend APIs and infrastructure for a healthcare platform — integrated AWS Cognito, location-based services, and secure user authentication.
- Axelus × Boratu System: Full-stack registration engine with cron jobs, social login, transactional email automation, and data export features.
- Humble Vessel Platform: Donation and volunteer platform with dual payment integration (Mobile Money + SWIFT), live chat, multilingual support, and headless CMS backend.
- Building reliable backend infrastructures for real-time systems and API orchestration.
- Exploring VoIP and telephony APIs to deliver global, high-availability voice alert platforms.
- Designing scalable systems that balance performance, security, and fault tolerance.
- 📧 Email: leojohnseyi@gmail.com
- 💻 GitHub
💡 "I believe the future of backend engineering is about orchestrating intelligent systems — combining APIs, cloud, and infrastructure into seamless digital experiences."