Sergey Smirnov

At Coherent Solutions, I build and maintain backend services for a higher-education course-materials platform serving 540,000+ active users. I work across five GraphQL microservices and own features from architecture through production support.

I design event-driven AWS pipelines that synchronize university sections, materials, enrollments, and payments. By fixing recurring integration pub-sub failures, I reduced data-integrity errors from 200–300 to 1–2 per month, and I increased Lambda batch throughput from roughly 500 to more than 5,000 records.

I also build partner API integrations and complex business logic, including restaurant POS integrations, billing reporting, discount flows, and caching with Redis. My work includes Python 2-to-3 migrations, CI/CD automation, automated testing, and daily collaboration with business customers and technical teams.

Through freelance work, I independently built production platforms including Oktavva Art, which replaced a manual Excel and email ordering process with a Django-based B2B configurator, and GPX-RS, an online accounting service with payments, permissions, chat, and banking-data processing.