Front end Engineer [Brazil]

About Arena:

Arena is a startup created in Silicon Valley with a mission to build communities for creators, publishers and brands with the power of AI. Companies using Arena include Disney, Reuters, Fox, Red Bull and NFL. We have +2,000 customers in 150 countries, with +50M users engaging and having conversations on Arena every month.

We are a Series A company backed by top-tier investors such as CRV, Redpoint and Craft Ventures. Arena offers a unique work environment and the chance to collaborate with diverse teammates across multiple countries, with a culture of ownership, autonomy, and high performance.

Arena is expanding its AI product portfolio with MyAvatar.AI, a multimodal platform that enables users to create intelligent, personalized AI avatars through voice, video, and conversational interfaces.

Sometimes you're stuck in a job that doesn't make sense, working with outdated code and a stack that holds you back. If you love a good challenge, enjoy solving meaningful problems, and want to be part of a fast-growing AI startup in Silicon Valley — then Arena is the company you're looking for.

About the Role:

We’re looking for a Frontend Engineer to build fast, scalable, and high-performance web experiences across Arena’s products.

You’ll work closely with Product, Design, and Engineering to build AI-powered features, improve existing applications, and solve complex frontend and performance challenges. You’ll work alongside experienced engineers and have a direct impact on products used by millions of users.

What you will be doing:

• Build and maintain high-performance frontend applications using React, Next.js, and TypeScript.
• Develop real-time experiences and interfaces using WebSockets and GraphQL.
• Build reusable, scalable, and maintainable UI components and frontend architecture.
• Integrate frontend applications with APIs, AI services, and backend systems.
• Optimize application performance, scalability, and reliability across high-traffic environments.
• Collaborate with Product and Design to turn product requirements and UI/UX concepts into polished experiences.
• Debug complex frontend and production issues and implement robust solutions.
• Contribute to AI-powered features, including conversational experiences and AI Agents.

Must-Have Experience:

• 3+ years of professional frontend engineering experience.
• Strong experience with TypeScript and React.
• Production experience with Next.js.
• Experience working with GraphQL and REST APIs.
• Experience building real-time applications using WebSockets.
• Experience with Git and collaborative software development workflows
• Experience working in monorepo environments.
• Strong problem-solving skills and attention to performance, scalability, and code quality.
• Fluent English

Our Stack:

• Frontend: React.js, Next.js, TypeScript.
• UI: Web Components, CSS, Styled Components.
• APIs & Real-Time: GraphQL, REST, WebSockets.
• Build & Architecture: Monorepo, Turborepo, Webpack.
• Infrastructure & CI/CD: GitHub Actions, Firebase, Firestore.
• Design: Figma.

Nice-to-Have Experience:

• Styled Components or other CSS-in-JS solutions.
• Turborepo, Webpack, or similar frontend tooling.
• GitHub Actions and CI/CD workflows.
• Node.js and backend development.
• Firebase and Firestore.
• Experience building browser extensions or WordPress plugins.
• Experience with AI-powered products, conversational interfaces, or AI Agents.

Example Projects You’ll Be Working on:

• Implement applications using Next.js framework
• Build a real-time chat that can scale to 1M simultaneous users
• Develop plugins for WordPress and Google Chrome
• Implement high-performance widgets
• Build a JavaScript SDK 
• Build and design AI features and AI agents

We also have some sweet perks like:

🔥 Be a part of the team in Silicon Valley and join a global team.
💪 A team of exceptional engineers leading the cutting-edge AI Agents.
💶 Competitive salary package & benefits.
⛱️ 4 weeks of paid time-off.
📖 Learning and Development budget.
🚀 Key moment to join Arena in terms of growth and opportunities.
💻 Ability to put your stamp on real-world AI applications that serve millions of users.
📚 Fast-learning environment, entrepreneurial and strong team spirit.
🌍 Multiple nationalities: cosmopolite & multi-cultural mindset.
💆‍♀️ Our people matter, work-life balance is important at Arena.