Pham Duy D.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

I am a Senior Full-Stack Engineer with 10+ years of experience designing, building, scaling, and operating SaaS platforms, fintech products, AI-powered applications, and cloud-native systems. For the past 5 years, I have been working at Money Forward, one of Japan's leading fintech companies, where I contribute as a Full-Stack Engineer and a key player in platform engineering initiatives. My responsibilities span application development, cloud infrastructure, CI/CD automation, Kubernetes operations, performance optimization, disaster recovery, observability, and scalable system architecture. Over the last 2 years, I have also focused heavily on AI-powered solutions, helping clients build applications using OpenAI models, GPTScript, AI agents, workflow automation, and LLM integrations. My strength is not only building software but also ensuring that systems remain scalable, reliable, observable, and cost-efficient in production environments. Technical Expertise Backend Development • Ruby on Rails • Node.js / Express • Python (Flask, Django) • Go • Elixir / Phoenix Frontend Development • React • JavaScript / TypeScript • HTML/CSS • jQuery Cloud & Platform Engineering • AWS • Kubernetes (EKS) • Docker • Terraform • CI/CD Pipelines • Infrastructure as Code • Auto Scaling • Disaster Recovery • Performance Optimization Observability & Reliability • Datadog (APM, Logs, Dashboards, Monitors, SLOs) • Grafana • Rollbar • Distributed Tracing • Incident Investigation & Root Cause Analysis • Production Monitoring • Capacity Planning • Cost Optimization AI Development • OpenAI API • GPTScript • AI Agents • Prompt Engineering • Workflow Automation • LLM Integrations • RAG-based Applications What I Can Help With • Build SaaS products from idea to production • Modernize and upgrade legacy applications • Design scalable cloud-native architectures • Implement Kubernetes and DevOps best practices • Optimize application performance and infrastructure costs • Integrate AI capabilities into existing products • Establish observability and monitoring strategies • Troubleshoot complex production issues • Automate development and deployment workflows Selected Experience • 10+ years of professional software engineering experience • 8+ years of Ruby on Rails development • 5+ years building and operating fintech products at Money Forward Japan • AWS Certified Developer • Successfully delivered AI, automation, SaaS, and cloud infrastructure projects for international clients • Extensive experience working with large-scale production systems and cross-functional engineering teams One of my key strengths is bridging the gap between software development, cloud infrastructure, and production operations. I enjoy solving challenging technical problems and helping businesses build reliable, scalable, and maintainable systems that can grow with their needs. If you are looking for an engineer who can contribute across application development, cloud architecture, DevOps, observability, and AI integration, I would be happy to discuss your project.