Valentyn – React, Ruby on Rails, JavaScript

Creator-first platform for content, courses, live streams, communication, and premium offerings

• Architected and led development of the platform’s community chat system, ensuring seamless integration with core services and reliable performance at scale.
• Designed and implemented real-time messaging, leveraging SSE and a NATS-based event delivery pipeline for low-latency, distributed message processing.
• Worked directly with the CTO to define technical strategy, evaluate architectural options, and translate evolving business requirements into scalable, production-ready solutions.
• Collaborated with Directors of Engineering to co-design and implement the platform’s third-party extensions framework (Shopify-like model), enabling safe, scalable feature extensibility by external developers.
• Partnered with product and design teams to ensure architectural alignment with UX and business goals, while maintaining performance, reliability, and extensibility standards.

A fintech startup that aims to improve credit scores and bill pay experience. The app makes it easy for people to consolidate their bills on the platform and pay them on time. It also provides a line of credit to report positive payment history to all major credit bureaus and help build credit.

• Led the front-end development of multiple user-facing web applications, ensuring consistent delivery quality, high availability, and alignment with product objectives.
• Managed front-end infrastructure and tooling, establishing best practices for performance, testing, CI/CD, and component-level reusability across the engineering organization.
• Provided technical leadership and mentorship, conducting code reviews, onboarding engineers, guiding architectural decisions, and supporting professional growth within the team.
• Collaborated with product management to review requirements and influence roadmap planning, ensuring technical feasibility, clear scope, and effective delivery timelines.
• Took on short-term Engineering Manager–like responsibilities such as coordinating work across teams, removing blockers, and improving communication workflows.
• Contributed to backend development (Ruby on Rails) by handling cross-functional tasks and complex feature implementations, supporting full-stack delivery when needed.

Leading cannabis production platform servicing the U.S. market. The idea is to take the technical expertise and apply it to the cannabis market, developing a platform that allows growers to grow more efficiently and increase their yields – and to do so consistently and at scale.

• Influenced FE architecture by delivering complex UI components like data-driven dashboards, recipe creation workflows, and multiple device integration, improving yield predictions and business metrics • Contributed to project planning, documentation, testing strategies, and efficiency improvements

A platform for IT vendors, suppliers, distributors, resellers, users. Social marketplace based on AI solutions connecting users and merchants allowing to find the best products for the best price.

• Built and improved UI.
• Built native SSR solution for SEO optimization.
• Contributed to architecture, code reviews, and performance tuning.

An application that finds a «lookalike» audience based on Artificial Intelligence and Human Intelligence approaches.

• Implemented business logic
• Created new features and UI
• Took care of code review