Hennadii Naumenko

Built and owned a multi-tenant SaaS platform for event, course, and content websites across multiple brands, coordinating work across several repositories and multiple backend microservices. Architected NestJS microservices for AI initiatives including a RAG pipeline (pgvector hybrid search, Cohere embeddings/reranking, AWS Bedrock) powering an in-product live chat, with tenant isolation enforced via JWT claims. Developed an AI agent workflow for event creation/editing through natural language with an allowed-change model and human confirmation. Led parallel migrations: replaced a legacy Express/Redux SSR engine with a modular Next.js architecture with per-tenant theming and live preview, and rebuilt the CORE Admin UI from Ember.js to React. Modernized a core data table by restructuring backend fetching and using React Table with React Query to reduce load times from seconds to sub-second performance, and rebuilt analytics tracking as a GA4 event contract across two frontends.

Built and maintained an API-first fintech platform admin dashboard for managing payment transactions and KYC workflows with configurable action assets. Implemented a high-performance transaction data table handling 10,000+ records with row virtualization, persisted configurable columns, and GraphQL data-layer integration for filtering and sorting. Optimized GraphQL performance with DataLoader to eliminate N+1 patterns and added query depth/complexity limiting for API hardening. Worked on GraphQL Federation to unify data across services, built a shared React component library with Storybook and tests, and delivered end-to-end testing with Cypress.

Integrated Amazon Comprehend for comment sentiment analysis and implemented nested comments with overall sentiment display. Replaced a custom SSR engine with Next.js and built tenant-aware React components supporting theming. Collaborated daily in English across product, design, backend, devops, and tech lead roles to deliver tenant-based voice-of-customer functionality.