Sergey User

I've built backend services for UNICEF HOPE, a platform that collects beneficiary and frontline-worker data and delivers humanitarian cash transfers. At Valor Software, I worked with Python, Django, Django REST Framework, Celery, Redis, and Pytest across country workspace, payment export, and deduplication capabilities.

I contributed to a deduplication engine that compares personal data and facial photographs, returning similarity-scored duplicate findings. It checks a 100K-person dataset in under two hours on two 1 Gi pods, improving on a previous rate of roughly 5K people per hour.

At giosg, I developed the backend for Workflow Builder using Django REST Framework, Celery, MongoDB, Pytest, and AWS. I introduced integration testing, reducing bugs per sprint from 3–5 to 0–1 and increasing production test coverage from about 50% to 80%.

Across 16 years in production engineering, I've delivered Java, Spring Boot, WebFlux, Django, PostgreSQL, AWS, Docker, and Kubernetes services for telematics, payments, cloud security, streaming, billing, and telecom products. I'm available immediately for an internationally remote senior backend role as an employee or contractor.