Senior Fullstack Developer (ReactJS / NestJS)

Aurum Data Solutions Inc.; São Paulo; Hybrid; BRL 279,000 - 391,000; Part time

Job summary

Senior UI Developer – ReactJS / Nest.js at Aurum Data Solutions Inc. in Sao Paulo, Brazil, offers a hybrid work arrangement on a contract basis.

You will lead UI development using ReactJS and Nest.js, shaping scalable, high-performance web applications and driving modern front-end practices. You will collaborate with UX/UI designers, backend engineers, and product owners; mentor juniors, participate in code reviews, and contribute to agile ceremonies.

Qualifications

• 10+ years of overall software development experience.
• Strong expertise in ReactJS and Nest.js frameworks.
• Proficient in TypeScript, Next.js, unit testing and modern JavaScript (ES6+).
• Hands-on experience with unit testing tools and frameworks such as Jest, Mocha or Cypress.
• Strong knowledge of HTML5, CSS3, SASS/SCSS, and responsive design.
• Experience with RESTful APIs, GraphQL, and client-server integration.
• Familiar with CI/CD pipelines and Git workflows (GitHub, GitLab).

Responsibilities

• Develop and maintain front-end apps using ReactJS and Nest.js.
• Write clean, documented code in TypeScript.
• Implement unit tests with Jest, RTL, or similar.
• Optimize performance and user experience.
• Collaborate with UX/UI, backend, and product teams.
• Mentor junior developers and participate in code reviews.
• Engage in agile ceremonies and stay current with frontend trends.

Skills

ReactJS

Nest.js

TypeScript

Unit testing

ES6+ JavaScript

HTML5

CSS3

SASS/SCSS

Redux

GraphQL

REST API

Git

GitHub

GitLab

Education

Bachelor’s or Master’s in CS/Engineering

Tools

Next.js

Jest

Mocha

Cypress

GitHub

GitLab

Job description

Job Title: Senior UI Developer – ReactJS / Nest.jsLocation: Sao Paulo, Brazil (Hybrid)Experience Level: 8+ Years (Mid-Senior Level)Employment Type: Contract

Job Description:We are seeking a highly skilled and experienced Senior Fullstack Developer with a strong background in ReactJS, Nest.js, TypeScript, and Unit Testing. The ideal candidate will have a proven track record of building scalable, responsive, and high-performance web applications. This role requires a collaborative mindset, attention to detail, and the ability to lead UI development initiatives from concept through execution.

Key Responsibilities

• Develop and maintain modern, scalable front-end applications using ReactJS and Nest.js.
• Write clean, efficient, and well-documented code using TypeScript.
• Implement unit testing frameworks (e.g., Jest, React Testing Library) to ensure robust code quality.
• Optimize application performance, scalability, and user experience.
• Collaborate with UX/UI designers, backend developers, and product owners to deliver seamless user experiences.
• Review and mentor the work of junior developers to ensure adherence to best practices and coding standards.
• Participate in code reviews, architectural discussions, and agile ceremonies (e.g., sprint planning, retrospectives).
• Stay current with front-end technologies and trends to drive innovation and best practices within the team.

Required Skills and Qualifications

• 10+ years of overall software development experience.
• Strong expertise in ReactJS and Nest.js frameworks.
• Proficient in TypeScript, Next.js, Unit testing and modern JavaScript (ES6+).
• Hands-on experience with unit testing tools and frameworks (e.g., Jest, Mocha, Cypress).
• Strong understanding of HTML5, CSS3, SASS/SCSS, and responsive web design.
• Familiarity with state management libraries such as Redux, Zustand, or Recoil.
• Experience with RESTful APIs, GraphQL, and client-server integration.
• Knowledge of CI/CD pipelines and version control systems (e.g., Git, GitHub, GitLab).
• Excellent problem-solving skills and attention to detail.
• Strong communication and collaboration skills.

Education

Bachelor’s or master’s degree in computer science, Engineering, or a related field.