Василина

VASYLYNA LEHETA
FULL-STACK DEVELOPER
Uzhhorod, Ukraine • English: Upper-Intermediate • GitHub: github.com/Mrexyha • email: [open contact info](look above in the "contact info" section)

PROFILE
Full-Stack Developer with 2.5 years of commercial experience across production web and mobile products. Hands-on
experience with TypeScript, JavaScript, React, Next.js, Node.js, NestJS, Express and Fastify, plus Scala/Play backend
services. Experienced in REST API development, authentication, database design and migrations, third-party
integrations, real-time communication, testing, Docker and cloud environments. Comfortable working across frontend
and backend, debugging production issues and collaborating with QA, mobile developers and product teams.

CORE TECHNICAL SKILLS
Programming Languages: JavaScript, TypeScript, Scala, Java, C#, Python, C++, SQL
Frontend: React, Next.js, Vue.js, Redux Toolkit, React Query, React Router, Tailwind CSS, Bootstrap, HTML5, CSS3
Backend & Frameworks: Node.js, Express.js, NestJS, Fastify, Strapi, TypeORM, FastAPI, .NET, WinForms
Real-Time & IoT: WebSockets, Socket.IO, MQTT, Mosquitto
Databases: PostgreSQL, MongoDB, MySQL, SQLite, Cassandra, MS SQL Server, Redis
API, Authentication & Integrations: REST APIs, Swagger/OpenAPI, Webhooks, JWT Authentication, OAuth, Firebase
Authentication, Groq API, Apple In-App Purchases, Google Play Billing, Postmark
Cloud & DevOps: Docker, AWS, Azure DevOps, Railway, Firebase, Google Cloud Storage, Nginx
Testing, Build & Development Tools: Cypress, Postman, ESLint, Webpack, Vite, Babel, npm, yarn, pnpm
Version Control: Git, GitHub
IDEs: VS Code, Visual Studio, IntelliJ IDEA, Cursor

PROFESSIONAL EXPERIENCE
Full-Stack Developer | 04.2025 – Present • Commercial software development
• Worked on production web and mobile products across smart home, wellness, social, marketplace and e-commerce
domains.
• Delivered features across frontend, backend APIs, databases, integrations and deployed environments.
• Collaborated with QA, iOS/mobile developers and product stakeholders to define API behavior, investigate defects and
deliver production fixes.
• Worked with JavaScript/TypeScript and Node.js ecosystems, as well as Scala/Play services, PostgreSQL, Cassandra,
Docker and AWS.

SELECTED COMMERCIAL PROJECTS
Anyware.Solutions | Full-Stack Developer
Production smart-home platform for multi-sensors and smart adaptors, with device/location management, telemetry,
dashboards, REST APIs, webhooks and Google Home/Alexa integrations.
• Implemented and maintained REST APIs and backend services for authentication/JWT, users, locations, adaptors,
rooms, scenes and sensor readings.
• Designed and optimized PostgreSQL and Cassandra data models and background jobs for external data
synchronization.
• Expanded React/TypeScript dashboard functionality and real-time data visualization using WebSockets.
• Extended and tested Google Home integration and webhook flows; validated APIs and devices with Postman.
• Investigated production issues and improved error handling, logging, JWT expiry checks and automated tests.
• Built Android test builds, investigated mobile-specific bugs and worked with the mobile developer to align API and UI
behavior.
Technologies: Scala, Play, PostgreSQL, Cassandra, React, TypeScript, Flutter, Tailwind CSS, Docker, AWS, Nginx, Azure
DevOps, WebSockets, Swagger/OpenAPI, Postman, Firebase
Mestre | Backend Developer
Strapi-based headless CMS backend for a wellness mobile platform, including authentication, content, search, favorites,
media progress, premium access, subscriptions and business administration.
• Developed and maintained REST APIs and business logic for accounts, content, subscriptions, companies, access codes,
favorites, topics and media.
• Implemented content discovery, search, premium access control and business administration workflows.
• Migrated the production platform from Strapi v3 to Strapi 5, including schema normalization, relation repair, data
backfill and database migrations.

• Worked directly with MySQL and SQLite, including data transfer, dialect-specific migration logic and schema
troubleshooting.
• Configured and debugged the pre-production environment on Railway and resolved environment-specific deployment
issues.
• Maintained Apple and Google in-app purchase validation, scheduled subscription checks, Firebase Auth, cloud storage
and email integrations.
Technologies: Node.js, Strapi 5, MySQL, SQLite, React, Railway, Firebase, Google Cloud Storage, Apple/Google In-App
Purchases, Postmark, cron jobs, Knex, Zod
Homio | Full-Stack Developer
Microservices-based smart-home management platform with adaptive automation, real-time monitoring, AI-powered
recommendations and simulated IoT devices.
• Implemented backend microservices and REST APIs for authentication, users, devices, automation rules and telemetry.
• Developed React dashboards for device monitoring, automation management and sensor-data visualization.
• Implemented WebSocket communication for real-time device updates and MQTT for simulated IoT telemetry.
• Designed PostgreSQL schemas and integrated an AI service for behavior analysis, anomaly detection and automation
recommendations.
• Containerized services with Docker and documented APIs with Swagger/OpenAPI.
Technologies: React, TypeScript, Redux Toolkit, React Query, Tailwind CSS, NestJS, TypeORM, PostgreSQL, Python,
FastAPI, scikit-learn, MQTT, WebSockets, Groq API, Docker
Stormy | Backend Developer
Native iOS social platform supporting stories, media, real-time messaging, push notifications, discovery and moderation
flows.
• Developed REST APIs with Node.js and Fastify, including Explore People and profile recommendation functionality.
• Implemented socket handlers and improved notification delivery and visibility rules.
• Fixed duplicate/outdated notifications and private-profile access issues based on follow status.
• Worked with iOS engineers, QA and Product to align API behavior with UX requirements and resolve
environment-specific issues.
Technologies: Node.js, Fastify, PostgreSQL, Docker, AWS (EC2, S3, CloudFront), Firebase, JWT/OAuth
EQuestrian | Backend Developer
Mobile-first marketplace for private and business users to create, browse and manage horse listings with rich media.
• Implemented business-account flows and CRUD functionality for advertisements.
• Added server-side rules for media limits, ordering and listing lifecycle.
• Built REST endpoints with route/controller/middleware separation, pagination, multi-field filtering and validation.
Technologies: Node.js, AWS, Firebase
CRM Platform | Full-Stack Developer
E-commerce CRM platform covering customers, products, orders, inventory, delivery integrations, payments and
analytics.
• Contributed to end-to-end development of the web CRM, including reusable frontend components and backend APIs.
• Integrated third-party delivery services and payment gateways.
• Implemented database models, optimized queries and developed background jobs for synchronization and automated
tasks.
• Aligned REST API contracts with frontend requirements.
Technologies: React, Next.js, NestJS, TypeORM, PostgreSQL, TypeScript, Tailwind CSS, Node.js, Express
LinguaLift | Full-Stack Developer
Online language-learning platform with interactive lessons, course management and learner progress tracking.
• Implemented React-based interactive lessons and Node.js/Express APIs for authentication and course management.
• Designed MongoDB schemas for users, lessons, questions and performance data.
• Created Cypress end-to-end tests for key user flows and participated in code reviews and pair programming.
Technologies: JavaScript, React, Node.js, Express, MongoDB, Cypress

EDUCATION
Bachelor’s Degree in Software Engineering | Uzhhorod National University | 09.2023 – Present | Expected 06.2027

ADDITIONAL
• ICPC 2023 — participant
• OPNU Internal Programming Contest 2024 — participant