Don Phelix

When a payment fails, a webhook goes missing or a financial system breaks under load, the consequences are real. I've spent 10 years building systems where that can't happen, and fixing them when it does.

I specialize in fintech and payment systems, having worked on production infrastructure including Trustly and M-Pesa integrations and cross-border remittance platforms. Beyond payments, I work across the full stack in Java Spring Boot, PHP Laravel, Angular, React and Flutter. I've led engineering teams, set architectural standards and delivered for clients in the US, UK and East Africa.

Professional Experience

TalkRemit, Remote (Full-time) May 2025 – Present Role: Backend Engineer, Payments

Building payin, payout and cross-border remittance processing systems using Java Spring Boot. Designing and implementing backend services following clean architecture principles on systems that handle real transactions at production scale.

The Blueion, Nairobi Kenya (Hybrid, Full-time) January 2024 – May 2025 Role: Software Lead

Led the engineering team in designing and delivering cross-platform applications. Established coding standards, conducted code reviews, mentored junior developers and worked directly with product teams to translate business requirements into technical specifications.

The Blueion, Nairobi Kenya (Hybrid, Full-time) September 2022 – December 2023 Role: Software Engineer

Designed, implemented and tested Flutter and Dart applications using the BLoC pattern for iOS, Android and Web. Built and consumed Laravel APIs and delivered features across multiple platforms.

Five-G Consulting, Inc., USA Texas (Remote) November 2021 – October 2022 Role: Software Consultant

Built a full-stack web application for IoT data visualization on Raspberry Pi devices. Implemented secure API integrations and an automated deployment framework for remote system updates.

iBuild Global, Inc., USA (Remote, Contract) January 2021 – November 2021 Role: Backend Developer

Optimized SQL queries for high-load systems, improving API responsiveness and reducing database costs. Managed performance monitoring and implemented structured bug tracking processes.

Tangaza (Pesaworld Ltd), Nairobi Kenya August 2019 – May 2021 Role: Full Stack Developer

Built and integrated APIs for a fintech company in the East African payments space. Developed responsive web applications and provided technical guidance to junior team members.

LSI Keywords, Remote (Upwork) September 2017 – July 2019 Role: Full Stack Developer

Designed and developed maintainable web solutions for SEO-focused products. Delivered tools that performed reliably at scale across multiple client accounts.

Mawingu Networks, Nanyuki Kenya January 2016 – May 2017 Role: Full Stack Developer

Worked with the development team on integration testing and new feature development for the company website.

Key Skills

Proficient in Java, PHP and JavaScript with strong TypeScript experience. Experienced in Spring Boot, Laravel, React, Angular, Vue.js and Flutter. Skilled in payment systems integration, RESTful API design and microservices architecture. Hands-on experience with Docker, Kubernetes, AWS and CI/CD pipelines. Proven technical leadership with experience mentoring developers and making architectural decisions.

If you are building something in the payments space or need a senior engineer who takes full ownership from architecture to delivery, let's talk about what you need.