Senior Frontend Engineer - React/Next.js, Cloud

Lever, Inc.; Polska; On-site; PLN 180,000 - 240,000; Full time

Job summary

Lever, Inc. is seeking a senior Front-end Engineer to design, build, and optimize React/Next.js applications. You will collaborate with BA, QA, and offshore teams to deliver high-performance web experiences.

You should have 5+ years, strong JS/TS, and cloud experience (GCP preferred). The role emphasizes scalable UI, testing, accessibility, and using AI-assisted tools to improve productivity while maintaining quality.

Qualifications

• 5+ years of professional experience.
• Excellent communication skills.
• Strong ownership and proactive approach.
• Strong experience in JavaScript and TypeScript.
• Thorough understanding of React/Next.js core principles, React Router, hooks, Redux, and web performance.
• Developing and maintaining modern distributed microservices.
• Cloud environments (Google Cloud Platform preferred).
• Building, testing, and troubleshooting high-volume web services using REST & JSON.
• Solid data structures and algorithms in JS.
• Semantic HTML expertise.
• CSS expertise with Tailwind, Styled Components, CSS Modules, and SASS.
• Browser-based debugging tools.
• Responsive and adaptive design.
• Experience with testing (Unit testing, react-testing-library, E2E).
• Experience using AI-assisted development tools (Claude, GitHub Copilot, etc.).
• Ability to apply AI tools for coding, debugging, testing, refactoring, and documentation.
• English (B2+).

Responsibilities

• Design, build and maintain efficient, reusable, and reliable code.
• Build React/Next.js based applications.
• Ensure the best possible performance, quality, and responsiveness of applications.
• Identify bottlenecks and bugs, and devise solutions.
• Help maintain code quality.
• Participate in agile team scrums and communicate status, roadblocks, and timelines.
• Collaborate with BA, QA, developers and offshore teams for planning, design, development, testing, and maintenance of web and mobile web apps.
• Share knowledge with the team during workshops.

Skills

JavaScript

TypeScript

React

Next.js

Web performance

Security

Semantic HTML

CSS (Tailwind, Styled Components, CSS)

Testing (Unit, react-testing-library,

AI-assisted development tools

English (B2+)

Tools

Docker

Contentful

NodeJS

GraphQL

GitHub Copilot

Job description

Lever, Inc. is seeking a senior Front-end Engineer to design, build, and optimize React/Next.js applications. You will collaborate with BA, QA, and offshore teams to deliver high-performance web experiences.

You should have 5+ years, strong JS/TS, and cloud experience (GCP preferred). The role emphasizes scalable UI, testing, accessibility, and using AI-assisted tools to improve productivity while maintaining quality.