ULENN TERRY CHERN

Non-profit solving global health challenges with innovative IoT and data solutions, serving as a key partner to Ministries of Health and local organizations in developing countries.

• Architected and built TechHub service management platform, designing RESTful APIs and backend services that enable Regional and District Immunization & Vaccine Officers (RIVO/DIVO) to create and track maintenance service requests for cold chain equipment across Rwanda's healthcare infrastructure.
• Lead architect for AI framework using Google Gemini and RAG with MyScale DB, streamlining vaccine fridge maintenance across partner countries in Africa and Asia. Implemented comprehensive CI/CD pipelines using GitHub Actions with automated pytest, pylint/black, mypy, eslint, and vitest workflows, plus branch protection rules requiring test coverage and automated deployment to AWS.
• Evaluated generative AI coding assistants (Cursor, Replit, Windsurf, Copilot) by refactoring legacy APIs and tests; in the process improving test coverage by 10%, code compliance by 40%, and API performance by 5-20%.
• Developed training materials and guidelines to enhance generative AI workflows, increasing code output by 30% and reducing sprint overages by 50%.
• Co-developed and deployed an AI chatbot MVP using ChatGPT and function calling, providing cold chain insights for 16k+ healthcare workers across Africa and India via web client and WhatsApp integration.
• Designed and built RESTful APIs for temperature monitoring device integrations with Haier (Uganda) and DHIS2 (Malawi), serving 1,400+ healthcare facilities and enabling real-time cold chain monitoring for Ministry of Health officials and field technicians across Uganda and Malawi. Project explained by product lead: youtu.be/ooLXL47246g?t=1600 .
• Optimized IoT data pipelines for real-time temperature monitoring from devices deployed across Kenya, Tanzania, and Malawi, achieving 5-10x performance gains with py-spy, Redis caching, and MongoDB aggregation.
• Built smart gateway framework for routing equipment alerts via cost-effective SMS providers, reducing missed alarms by 10% and SMS costs by 25% and cutting new gateway deployment times from weeks to a single day.
• Developed technical solution for IoT power monitoring pilot program, building analysis tools to merge electrification data and creating alert logic for grid/generator outage detection that prevented deadly blackouts across 8 hospitals in Kenya.

• Streamlined installation workflow for field devices, reducing errors by 30% and setup time from 10+ to under 3 minutes per device.
• Sanitized system data and implemented robust validation with detailed error messaging, reducing user tickets by 10% and errors by 30%.
• Transitioned legacy pages to Django REST Framework APIs and led Angular SPA migration, creating comprehensive backend documentation and improving test coverage by 10% to support the new architecture.
• Mentored new engineers through regular 1:1s with ongoing feedback and created onboarding materials to accelerate ramp-up, participated in technical interviews and hiring decisions while advocating for team members' career advancement.

Public research university known for engineering, science, and technology programs.

• Taught Computer Science with Python, developing new curricula and teaching methods that contributed to a 10-point average grade increase across all cohorts.
• Created lesson plans, assessments, and provided individualized feedback to support student success.

Real-time data solutions specializing in travel and leisure industries.

• Updated and cleaned client-facing database, reducing duplicate and erroneous records by 40%, and built data validation toolkit using Google Places API to reduce hotel data trouble tickets.
• Designed and developed RESTful APIs serving travel industry clients, enabling real-time hotel data access for booking platforms and reducing operational overhead by 15%.