Senior Frontend Developer [React]

Ailleron; Kraków; Hybrid; PLN 240,000 - 300,000; Full time

Benefits offered by this job

Atmosphere: Great Place To Work

Health Care and Sports Card

Language classes during work hours

Life insurance

Well-being programs and team events

Job summary

Ailleron is seeking a Senior Frontend Developer to join our team working on an online banking platform for a business client. You will contribute to application development with the latest technologies, implement new features, and enhance existing functionality for banking software.

We value strong React 18 proficiency, TypeScript, testing practices, and collaborative workflows. The role involves maintaining an existing codebase and working in a team with modern CI/CD processes.

Qualifications

• Strong knowledge of React 18 and its core concepts, including hooks, context, component lifecycle, and design patterns.
• Experience with React Hook Form for forms.
• Hands-on experience with React Query v5 for async data handling.
• Ability to debug and optimize using DevTools.
• Proficiency with TypeScript in large-scale projects.
• Good Git skills and collaborative workflows (PRs, code reviews).
• Experience with npm and Yarn as package managers.
• Ability to write unit and integration tests (Jest + React Testing Library).
• Experience maintaining and extending existing codebases.
• Theoretical knowledge of monorepos and Nx; practical is a plus.
• Experience with CI/CD and automation.

Responsibilities

• Actively contribute to application development using the latest technologies.
• Implement new features and enhance existing functionality.
• Develop modern banking systems used by large financial institutions.

Skills

React 18 (hooks, lifecycle)

React Hook Form

React Query v5

TypeScript

Git

npm & Yarn

Jest & RTL

Monorepos & Nx

CI/CD tooling

Debugging with DevTools

Performance optimization

End-to-end testing basics

Tools

React

Jest

React Testing Library

Nx

CI/CD tools

Monorepos

Job description

At Ailleron, we specialize in financial software development services.

We are looking for a Senior Frontend Developer to join our team. We are working on a project for the banking sector, developing an online banking platform for a business client.

What will you do?

• Actively contribute to application development using the latest technologies.
• Implement new features and enhance existing functionality.
• Develop modern banking systems used by some of the largest financial institutions in our market.

What skills and experience are we looking for?

• Strong knowledge of React 18 and its core concepts, including hooks, context, component lifecycle, and design patterns.
• Experience working with forms using React Hook Form.
• Hands-on experience with React Query v5 for asynchronous state management and data synchronization.
• Ability to debug and optimize applications using developer tools, such as React DevTools.
• Experience with TypeScript in large-scale projects.
• Good knowledge of Git and experience working in a team environment, including pull requests and code reviews.
• Experience working with package managers, such as npm and Yarn.
• Ability to write unit and integration tests using tools such as Jest and React Testing Library to ensure code quality.
• Experience maintaining and extending an existing codebase.
• Theoretical knowledge of working with monorepos and Nx; practical experience is a plus.
• Experience with CI/CD tools and development process automation.

Nice to have

• Basic knowledge of end-to-end testing tools, such as Cypress or Playwright.
• Ability to optimize frontend application performance.

A host of benefits you’ll appreciate

Atmosphere

Working at a friendly company recognized as a Great Place To Work and awarded the Friendly Workplace distinction

Self-development

80 hours to develop your skills during work hours

Health

Health Care and Sports Card

Education

Language classes during work hours

Safety

Life insurance tailored to your needs

Integration

Well-being programs, team-building activities, and events