Middle Frontend JavaScript/TypeScript Developer (React, Next.js)

We’re Black Whale Labs — a product-focused tech team working on user-centric platforms in the Web, gaming, and blockchain domains. We value a modern engineering culture, clear communication, and responsibility in delivery.

We’re looking for a Middle Frontend Developer experienced with JavaScript/TypeScript, React, and Next.js, who can write clean, maintainable code and collaborate closely with design, backend, and product teams.

About the Project
The project consists of two parallel frontends:
1. Legacy Frontend (current production app) - an old architecture with some outdated libraries. Actively used by real users and still needs maintenance + feature development
2. New Frontend (greenfield project) that we are aiming to rebuild completely from scratch using modern technologies:

• Next.js
• React latest version
• TypeScript
• Modern component library / design system
• Better architecture, improved UX, optimized performance
• Gradual migration of functionality from the legacy app

You will work on both: Maintain and evolve the old app and help build the new one from zero.

Responsibilities
Work on Legacy Frontend (React 14 + JS)

• Implement new features and improvements using legacy React components (class-based + older patterns)
• Maintain, debug, and refactor legacy code without breaking existing functionality
• Fix UI/UX issues, bugs reported by users, and small regressions
• Improve code gradually where reasonable (but without rewriting whole modules)

Build New Frontend from Scratch (Next.js + TS)

• Participate in designing architecture, code style, and technical foundations of the new app
• Build new modules, pages, components, and layouts using React + Next.js and TypeScript
• Migrate functionality from old app to new one step-by-step
• Work closely with backend engineers to integrate new APIs
• Ensure type safety, clean code, performance and best practices
• Contribute to building a shared component library/design system

General Responsibilities

• Write clean and reusable code (JavaScript + TypeScript)
• Collaborate with UX/UI designers to implement UI
• Communicate proactively with product team and other developers
• Help shape processes and best practices as the new project evolves
• Identify issues, suggest improvements and technical solutions

Requirements
Must-Have

• 2+ years of experience in frontend development
• Strong skills in JavaScript (ES6+)
• Solid experience with React (Hooks, state management, lifecycle, class components are a bonus)
• Experience working with legacy codebases
• Strong knowledge of HTML5, CSS3
• Experience with REST API integrations
• Good understanding of bundlers (Webpack)
• Experience with Git and collaborative development
• Ability to read, navigate, and improve older code
• Strong troubleshooting skills
• Experience with Next.js
• Good understanding of TypeScript (types, interfaces, generics)
• Understanding of frontend architecture and best practices

 Nice-to-Have

• Experience building component libraries or design systems
• Knowledge of Redux Toolkit
• Experience with testing
• Basic backend familiarity (Node.js / NestJS)
• Experience with CI/CD and DevOps-friendly workflows
• Figma experience

What We Offer

• Opportunity to work on a full rebuild of a production-scale frontend
• Work with modern stack (Next.js, TypeScript, React latest)
• Long-term technical challenges and space for professional growth
• A small, highly skilled engineering team and no bureaucratic overhead
• Competitive salary
• Flexible schedule
• Paid vacations and sick leaves
• 4 days working week (Mon-Thu)