Oleksandr – Node.js, React, Express.js

The project was a large-scale online sports betting platform for users who followed live sports events and placed pre-match or in-play bets. Its main features included real-time odds and market updates, live event tracking, sports navigation, bet selection, promotions, and responsive interfaces for desktop and mobile.

I worked as a frontend-focused engineer within the infrastructure team, helping maintain and modernize the shared platform used by multiple product areas.

• Developed and improved real-time betting functionality with live event, market, and odds updates.
• Integrated frontend features with WebSocket connections and backend APIs.
• Contributed to the migration of selected legacy functionality to Vue 3, TypeScript, and Nuxt.
• Worked on the SSR migration of the landing page while preserving compatibility with the legacy platform.
• Maintained and improved shared frontend infrastructure used across multiple product areas.
• Refactored legacy PHP, Backbone, and Vue code to improve maintainability and support gradual modernization.
• Improved application performance, SSR readiness, and consistency between desktop and mobile interfaces.
• Wrote unit tests for shared adapters, selectors, composables, and navigation logic.
• Investigated and resolved production issues related to state management, live subscriptions, and user interactions.
• Used Cursor daily as an AI pair-programming tool for code analysis, implementation, refactoring, debugging, and test generation.

The project was a large-scale cloud-based construction management platform used by construction teams to manage project documents, collaboration, compliance, finances, and risks. I worked on the core Documents domain, contributing to document-related services and helping modernize the system from a monolithic application toward a service-oriented architecture. My role included full-stack development with React, TypeScript, and NestJS, REST API integrations, and asynchronous document-processing workflows.

• Developed and maintained full-stack functionality for the core Documents domain using React, TypeScript, NestJS, and PostgreSQL.
• Built REST APIs and asynchronous workflows for PDF upload, validation, background processing, status tracking, preview, and download.
• Worked on document-related microservices, including Document Upload, Document Processing, Metadata and Versioning, and Notification services.
• Developed React microfrontends for the Document Library, file upload and processing status, PDF preview, version history, and document collaboration workflows.
• Integrated microfrontends with REST and GraphQL APIs and improved reliability through Jest unit and integration tests, code reviews, and production troubleshooting.

The project was a healthcare platform supporting patient management and care coordination workflows. It enabled healthcare teams to access and manage patient-related information, track interactions, and collaborate across different stages of care. I worked as a Full-Stack Engineer, developing responsive React interfaces, backend functionality, GraphQL integrations, and reliable data flows using PostgreSQL and Apollo

• Developed React and TypeScript modules for patient profiles, care plans, care-team assignments, and patient interaction history.
• Built and integrated GraphQL APIs for retrieving and updating patient data, care tasks, appointments, and workflow statuses.
• Developed and maintained backend services for Patient Management, Care Coordination, and Task Management using Node.js, Express.js, and PostgreSQL.
• Designed PostgreSQL schemas and optimized queries for reliable storage and retrieval of patient and care-related data.
• Implemented Apollo Client caching and state-management flows and added Cypress end-to-end tests for critical patient-management workflows.

The project was a data-driven advertising platform that used real-time search intelligence to help brands and agencies understand consumer intent, discover relevant audiences, analyze market trends and activate advertising campaigns. I worked on the self-service web application, developing frontend and backend functionality for audience insights, campaign-related workflows, data visualization, and integration with internal analytics services

• Developed data-heavy dashboards for exploring audience interests, consumer trends, brand performance, and campaign insights.
• Built functionality for creating, configuring, saving and managing custom audience segments based on search-intelligence data.
• Developed and integrated backend APIs for audience management, campaign workflows, reporting and communication with internal analytics services.
• Improved the performance of large datasets and visualizations through pagination, filtering, caching, and API query optimization.
• Expanded automated test coverage, refactored existing modules, and collaborated with product and data teams on delivering new platform functionality.