99x Brazil is seeking a Senior AI-first Product Engineer to join our growing team. We are looking for engineers who take full ownership of products and features from discovery to production, operate comfortably across the stack, and use AI as a core part of how they design, build, and scale solutions.

You will help shape technical direction, work directly with clients and stakeholders, and contribute to the evolution of engineering practices within teams, while remaining accountable for product quality, performance, and outcomes long after deployment.

Responsibilities

• Own product features end-to-end, from problem definition and architecture to deployment, monitoring, and continuous improvement
• Build AI-driven product experiences and integrate modern AI tools into the engineering workflow
• Collaborate cross-functionally with product, design, engineering, and business stakeholders to deliver impactful solutions
• Contribute across the stack, including frontend, backend, APIs, integrations, and cloud-based services
• Represent the company in technical and commercial discussions with clients, partners, and stakeholders
• Drive technical discovery sessions, solution design, and architecture discussions
• Mentor and upskill engineering teams on AI-assisted development practices and modern engineering workflows
• Optimize applications for performance, scalability, maintainability, and user experience
• Write clean, maintainable, well-tested, and well-documented code
• Stay up to date with emerging technologies, AI trends, and modern software engineering practices

Requirements

• 6+ years of experience in software engineering, with strong expertise in React, Next.js, TypeScript, Node or Python
• Proven experience building and scaling modern web applications across the full stack
• Strong understanding of software architecture, distributed systems, APIs, and scalable application design
• Hands-on experience using AI tools and AI-assisted development workflows as a core part of the engineering process
• Demonstrated product ownership mindset, with experience leading features or products from discovery to production and beyond
• Ability to think from first principles, challenge assumptions, and solve complex business and technical problems
• Strong communication and presentation skills, with the ability to represent technical solutions in client-facing and commercial discussions
• Proven experience mentoring engineers and driving AI upskilling initiatives within development teams
• Solid understanding of modern frontend development practices, component architecture, and responsive design principles
• Familiarity with cloud platforms, CI/CD pipelines, monitoring, and modern DevOps practices
• Advanced English communication skills, both written and verbal

Benefits

• Your pick when it comes to employment models: CLT/PJ/Cooperativa;
• A fully remote work environment with flexible working hours;
• Bonus for any referrals that we end up hiring.