Core Experience Engineer - Senior Software Engineer

​​🌎 Onsite — Caxias do Sul, Brazil

💰 $57,000 USD + Equity & Benefits

About TestBox

TestBox was founded with a bold mission: to fundamentally transform how software is bought and sold. We’re building an innovative platform that empowers buyers with transparent, interactive software experiences, while equipping sellers with powerful tools to deliver exceptional buying and onboarding journeys. Our core technologies - synthetic data, intelligent orchestration, and our unique product graph - help teams achieve faster implementations, clearer insights, and increase trust with their customers.

At TestBox, we're not just improving demos; we're building the next generation infrastructure for software transactions, creating seamless experiences from initial interest to successful onboarding and beyond.

We're a fast-growing startup built by a team that values experimentation, velocity, and customer impact. We’re backed by world-class investors and are building a platform that’s disrupting the traditional B2B sales motion.

Role Overview

We’re looking for a Senior Software Developer who loves building product experiences and thrives in a fast-paced startup environment. You’ll be a key contributor to our core product, working across the stack to solve complex problems, deliver new features, and help shape the future of demo automation.

You’ll collaborate closely with Product and other Core Engineers to bring ideas to life and ensure we continue delivering an exceptional experience for our customers.

What You'll Do

• Build and maintain core features across the TestBox platform (Front-End and Back-End)
• Take ownership of technical projects from design to deployment
• Collaborate with Product to ensure we’re building the right solutions for our customers
• Contribute to technical decisions and direction alongside the Tech Lead and Engineering team
• Write clean, maintainable, and well-tested code
• Participate in code reviews and provide thoughtful feedback to peers
• Debug and resolve production issues as part of our shared on-call rotation

Preferred Experience

• 4+ years of professional software development experience
• Experience working across the full stack (React, Django)
• Strong knowledge of API design and integrations (REST, GraphQL, or similar)
• Familiarity with cloud infrastructure (AWS, GCP, or Azure)
• Comfort working in a startup or fast-paced, product-driven environment
• A proactive, ownership mindset! You enjoy taking projects from concept to completion
• Excellent collaboration and communication skills

Why Join TestBox

• Build foundational, greenfield systems from the ground up and make a massive impact from day one.
• Solve challenging and rewarding UI/UX problems for a technical user base.
• Define the frontend architecture and best practices that will shape the company's product for years to come.
• Join a company obsessed with customer experience, speed, and scale.

Benefits

• Generous equity package for meaningful ownership.
• Prioritization of your professional growth, with dedicated career development support.
• Flexible, unlimited PTO with a minimum expectation for recharge.
• Mental Health benefits.
• Fitness allowances.
• Learning allowances.
• Remote and office setup allowances to ensure productive and comfortable working environments.