Desenvolvedor(a) Frontend Senior | React/Next.js

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Desenvolvedor(a) Frontend Senior | React/Next.js based in Brazil.

This role is an opportunity for a senior frontend engineer to build and evolve high-performance digital experiences used by millions of customers.
You will work on modern web applications, combining frontend development expertise with analytics, observability, and performance optimization.
The position focuses on creating scalable, accessible, and reliable interfaces while improving user experience across the digital journey.
You will collaborate with multidisciplinary teams to solve complex challenges, analyze data, and deliver impactful solutions.
Working with technologies such as React, Next.js, TypeScript, and Redux, you will contribute to the evolution of a high-traffic platform.
This is an ideal opportunity for professionals passionate about engineering excellence, innovation, and creating seamless digital products.

Accountabilities:

The Senior Frontend Developer will be responsible for developing, maintaining, and optimizing frontend applications while ensuring performance, scalability, accessibility, and data reliability. This role combines strong technical execution with analytical capabilities to improve user experiences and support continuous product evolution.

• Develop and evolve frontend applications using React, Next.js, TypeScript, and Redux.
• Build high-performance interfaces using Server-Side Rendering (SSR), ensuring strong SEO and navigation experiences.
• Create reusable, accessible, and maintainable components following frontend best practices.
• Integrate and consume REST APIs, including authentication flows and error handling.
• Implement automated tests using Jest and React Testing Library.
• Instrument and analyze observability and analytics data, ensuring accuracy and consistency of collected information.
• Correct and standardize tracking implementations, ensuring proper event naming and data collection throughout the customer journey.
• Analyze collected data to identify root causes, instrumentation gaps, and opportunities for improvement.
• Monitor and improve application performance using Web Vitals metrics and production insights.
• Support production environments through incident analysis, troubleshooting, and continuous optimization.
• Document technical solutions and participate in code reviews to promote engineering best practices.
• Collaborate with cross-functional teams to deliver reliable and impactful digital solutions.

Requirements:

The ideal candidate has strong experience building production-grade frontend applications, with deep knowledge of modern JavaScript frameworks and a strong focus on quality, performance, and user experience. The professional should be analytical, collaborative, and comfortable working with complex digital products.

• Bachelor’s degree completed in Technology or related fields.
• Solid professional experience with React and TypeScript in production environments.
• Experience with Next.js, including SSR, routing, hooks, and middleware.
• Knowledge of state management using Redux or Redux Toolkit.
• Experience with web analytics and observability instrumentation, including event tracking, metrics, and telemetry.
• Experience with product analytics tools such as Amplitude, GA4, Mixpanel, or similar platforms.
• Ability to analyze data, identify root causes, validate hypotheses, and measure business impact.
• Strong understanding of data quality practices, including naming consistency, event governance, and privacy considerations.
• Experience with UI libraries, component-based development, and frontend architecture.
• Knowledge of REST API integrations and frontend-backend communication.
• Understanding of accessibility best practices.
• Experience with automated testing and Git version control.

Nice-to-have skills:

• Experience with monitoring and observability tools such as Datadog, New Relic, Grafana, or Kibana.
• Strong knowledge of web performance optimization and Web Vitals metrics (LCP, CLS, INP).
• Experience with A/B testing, experimentation platforms, and feature flags.
• Familiarity with Kubernetes, Rancher, or container orchestration environments.
• Experience working with high-traffic e-commerce or retail platforms.
• Knowledge of micro frontend architectures.

Benefits:

• Health insurance.
• Dental insurance.
• Meal or food allowance.
• Telemedicine services.
• Gympass fitness benefits.
• Access to SESC partnerships.
• Profit Sharing Program (PLR).
• Private pension plan.
• Group life insurance.
• Pharmacy partnerships and discounts.
• Educational partnerships and learning opportunities.
• Online learning platform access.
• Employee discounts on products and services.
• Opportunity to work on large-scale digital projects with modern technologies.
• Collaborative environment focused on innovation, diversity, and professional growth.

How Jobgether works: We use an AI-powered matching process to ensure your application is reviewed quickly, objectively, and fairly against the role's core requirements. Our system identifies the top-fitting candidates, and this shortlist is then shared directly with the hiring company. The final decision and next steps (interviews, assessments) are managed by their internal team. We appreciate your interest and wish you the best!  Why Apply Through Jobgether?    Data Privacy Notice: By submitting your application, you acknowledge that Jobgether will process your personal data to evaluate your candidacy and share relevant information with the hiring employer. This processing is based on legitimate interest and pre-contractual measures under applicable data protection laws (including GDPR). You may exercise your rights (access, rectification, erasure, objection) at any time.     #LI-CL1