QA Engineer

Location: Brazil Remote

Department: Engineering

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 and with +50M users having conversations on Arena per month and engaging with our AI tools.

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, growth, and specially high performance).

Sometimes you're stuck in a job that doesn't make sense. Managing tasks and infinite backlogs, not talking to customers and miles away from making product decisions. If you love a good challenge, you're a curious product guy who experiments with AI and AI agents every day, and you want to be a part of one of the fastest-growing AI startups in Silicon Valley — then Arena is the company you're looking for.

About the Role:

We’re looking for a QA Engineer who’s passionate about technology, curious about how things work, and eager to ensure quality across our products. You’ll join a supportive, fast-paced environment and collaborate with experienced engineers to test web applications, APIs, and new features as they’re developed.

This is a great opportunity to grow in a company that values mentorship, ownership, and continuous learning.

What you will be doing:

• Collaborate with product and engineering to understand requirements and define test strategies.
• Write and maintain **manual and automated test cases** for web applications and APIs.
• Run exploratory and regression tests for new features and releases.
• Help monitor issues in production and identify patterns for improvement.
• Contribute to maintaining and expanding our automated test suite using Cypress and Jest.

The challenges:

• Real-time messaging to support 100,000 concurrent users per customer application;
• High performance: our API responses are in the 10ms range;
• High scalability: we use sharding, master-master, and master-slave to ensure scalability;
• High availability: our code is running on homepages of the most visited websites and apps in the internet;
• Distributed databases for our Data Platform storing every user engagement.

You Might Be a Fit If You Have:

• Some experience (6–18 months) in QA or testing software
• Familiarity with tools like Cypress, Jest, or Selenium.
• Basic knowledge of JavaScript or TypeScript.
• Understanding of REST APIs and how to test them.
• Enthusiasm to learn, ask questions, and work in a collaborative environment.
• Advanced English (spoken and written).

Nice-to-Have Experience:

• Experience with HTML/CSS and browser dev tools.
• Exposure to mobile testing (iOS or Android).
• Understanding of how CI/CD and deployment pipelines work.
• Curiosity about how distributed systems scale.

Example Projects You’ll Be Working on:

• Build automated test suites and test cases for web apps, mobile apps, and APIs;
• Build early warning systems that detect production environment errors;
• Certify production releases;
• Manual testing, where necessary – we prefer automated tests!
• Continuously improve and maintain quality standards;
• Analyze error patterns to identify repeating types of issues;
• Monitor error and debug sources for production issues.

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