Senior Frontend Developer (React)

Phenomenon Studio is a full-cycle design and development company founded in 2019.
We help startups and small to medium-sized businesses build and scale products across Healthcare, EdTech, SaaS, FinTech, and Web3 industries.
Recognized with 30+ industry awards, we deliver high-quality solutions that combine creativity, technology, and business impact.

We’re looking for a Senior Frontend Developer for an all-in-one SaaS platform that helps agencies and creators manage large-scale social media operations.
Today, these teams rely on spreadsheets, Discord, and multiple disconnected tools to handle scheduling, payroll, analytics, and communication. The platform replaces all of that with one centralized system.
Think of it as: workforce management + scheduling + payroll + analytics + messaging + automation in a single web app.
This is an operations-focused product built around dashboards, real-time systems, and complex business logic rather than a marketing-oriented application.
You will help build a scalable web platform with team and role management for large organizations, shift scheduling and availability planning, time tracking, and automated payroll with bonuses and commissions. The system includes performance and sales analytics dashboards, real-time messaging, workflow automation, and role-based access control. It also supports integrations with external platforms and high-volume data processing and reporting.

Team: 3x Backend Developers, 3x Frontend Developers, Solution Architect, PM, BA, QA, DevOps, Designer

Requirements:

• 5+ years of experience in JavaScript, TypeScript, React
• Valid, cross-browser, and high-quality layout
• Strong expertise in HTML and CSS
• Strong expertise in ECMAScript and the DOM API
• Strong expertise in React (concurrent features,  composition and compound patterns, compiler)
• Strong knowledge in CSS Modules, TailwindCSS, Radix Ul/Base UI, Shadcn/ui
• Strong expertise in Tanstack Router and Tanstack Query
• Experience with Zustand, Tanstack Form, Recharts/ECharts
• Strong expertise in performance optimization and UX improvements (code splitting, bundle size, virtualization, CLS, LCP, optimistic updates)
• Experience with a11y (keyboard accessibility, screen reader compatibility, zoom and user preferences)
• Experience with real-time data (WebSocket, SSE)
• Experience with AI agents usage (Claude Code/Codex CLI/Gemini CLI)
• Upper-intermediate English level
   

Nice to have:

• Experience with Vitest, Testing Library, Playwright, Storybook
   

Responsibilities:

• Build and scale a complex frontend application from scratch
• Contribute to frontend architecture (state, data flow, performance)
• Deliver dashboards and workflow-heavy features: scheduling, time tracking, payroll flows, analytics
• Implement integrations and automation flows
• Collaborate closely with backend & product on business-critical features
   

What we offer: 

• Remote work format and flexible schedule
• Autonomy in work, opportunity to build processes, and grow within the company
• Individual development plan and annual performance review
• Workshops and playgrounds for continuous learning
• Compensation for subject-matter training
• Corporate English classes
• Access to IT Loyalty Club
• Accounting support
• 18 working days of annual leave
• 7 working days of sick leave and 7 working days of unpaid leave
• All national public holidays off
   

Recruitment process: Recruitment interview - Technical interview - Final interview