Middle/Strong Middle FullStack JavaScript Engineer (React/NodeJS)

About the Position

UKEESS Software House is looking for a Middle/Strong Middle FullStack JavaScript Engineer (React/NodeJS) to join our team for a full-time position (in Lviv, Ukraine).

About the Project and Team

Our customer is the world’s largest family history and consumer genetics company. With more than 60+ billion digitized global historical records, 100 million family trees, and 18 million people in a growing DNA database, our client helps customers discover their family stories and gain actionable insights about their health and wellness. Are you passionate about dedicating your work to enriching people’s lives? Join us!

Our team owns a major portion of customer-facing web applications, serving over 3.5 million daily views. We focus on delivering a fast, engaging, and intuitive search experience to help users make meaningful genealogical discoveries. We work with a vast dataset of over 60 billion historical records, leveraging data aggregation techniques, efficient caching strategies, and orchestrated components to ensure performance and scalability. Our mission is to surface the most relevant insights quickly, making the exploration of family history as seamless and impactful as possible.

Tech stack of the project:

React/Redux/ReduxToolkit/Tanstack/JS/TS/NodeJS/Express/EJS/MicroFrontends/ModuleFederation/AWS(ECS/ElasticCache/Lambdas/CloudWatch/S3)/Valkey/Redis/MemCache

Responsibilities

• Designing, building, and maintaining high-quality, production-grade web applications using TypeScript/React/NodeJS.
• Improving reliability and availability through resilient design, graceful degradation, and operational excellence in production.
• Developing and maintaining aggregation-layer functionality, applying effective logging and caching patterns to optimize latency and cost.
• Partnering with product, design, analysts, and backend teams to deliver features end-to-end, from discovery through launch and iteration.
• Supporting production operations: on-call participation as needed, incident triage, root-cause analysis, and postmortems.
• Implementing robust client-side architecture, including reliable state management, data fetching, and rendering strategies (SSR/SSG where applicable).
• Innovating on architecture, tooling, and developer experience-proposing and piloting improvements that increase delivery speed, quality, and maintainability.
• Driving accessibility improvements and ensuring compliance with WCAG standards through audits and continuous enhancements.

Requirements

• 3+ years of commercial experience with NodeJS and React
• Proficiency integrating AI coding agents (e.g., Copilot/ChatGPT/Cursor) into daily development workflow while maintaining high code quality, security, and reliable test coverage
• Solid TypeScript experience, including strong typing, modern language features, and building/maintaining production-grade applications
• Strong understanding of JavaScript performance, browser rendering lifecycle, event loop/asynchrony, and memory management (GC, leaks, profiling).
• Solid grasp of web security fundamentals (e.g., XSS, CSRF, CORS, CSP, authentication/authorization, secure storage).
• Experience with React rendering behavior and state management patterns (reconciliation, memoization, concurrency basics, Redux/Zustand/Context, server state).
• Working knowledge of bundlers and JS tooling/compilers (Webpack/Vite/Rollup, Babel/SWC/TypeScript), including build optimization and code-splitting.
• Understanding of high-availability system design: resilience, fault tolerance, graceful degradation, and SLO/SLA thinking.
• Commitment to accessibility best practices (WCAG, semantic HTML, ARIA, keyboard navigation, testing with assistive tools).
• Applied knowledge of logging and caching approaches for aggregation layers (structured logs, correlation IDs, sampling, metrics/tracing, cache key design, invalidation strategies).
• Basic knowledge of cloud infrastructure, availability, load balancing, and DNS
• Experience with cloud providers (AWS preferred)
• Experience with CI/CD
• English: Upper-Intermediate level at least (both spoken and written)

Nice to Have Skills

• Ability to optimize web performance and SEO (Core Web Vitals, SSR/SSG, hydration, caching headers, metadata, structured data).
• Applied knowledge of caching strategies, including eviction policies (LRU/LFU/TTL), sharding/partitioning, and multi-layer caching approaches.
• Proven experience supporting enterprise-grade applications in production, including incident response, debugging, and postmortems.
• Recent experience or good understanding of the micro-frontend pattern
• Experience with Relational databases
• CS degree

We Offer

• Full-time position in a highly professional team
• Competitive compensation (based on market data, but also depending on the technical level of the candidate)
• Flexible work schedule
• Individual approach to professional growth
• Free English classes (online)
• 3 health packages to choose from
• Annual paid vacation and state holiday celebration
• Lack of bureaucracy and micromanagement
• Foreign business trips (after the war)

Our office in Lviv has ​​generators and stable communication in case of “no electricity”. Also, you will have the:

• Modern, comfortable office facilities (a barbecue zone, kitchens, lounge rooms, coffee machines, etc.)
• On-site parking lot and charge station for Electric Cars
• Corporate gifts, celebrations, and fun activities
• Sports activities: ping-pong, soccer, workout

Contact Us

Recruiter

Anastasiia Smeiko

+38(068)344-22-00

[email protected]

Location

Lviv, Remote, Ukraine

Technology

AWS, CI/CD, Node.JS, ReactJS, TypeScript