Core Experience Engineer – Senior Software Engineer

Location: Onsite — Caxias do Sul, Brazil
Compensation: $57,000 USD + Equity & Benefits

About TestBox

TestBox is on a mission to fundamentally transform how software is bought and sold. They’re building a platform that empowers buyers with transparent, interactive software experiences while equipping sellers with tools to deliver exceptional buying and onboarding journeys.

They are a fast-growing startup that values experimentation, velocity, and impact. Backed by world-class investors, we’re disrupting the traditional B2B sales motion.

Role Overview

We are seeking a Senior Software Developer who thrives in fast-paced startup environments and enjoys building exceptional product experiences. As a key contributor to our core product, you will work across the stack to solve complex problems, deliver new features, and help shape the future of demo automation.

You will collaborate closely with Product and Core Engineering teams to bring ideas to life and ensure an outstanding experience for our customers.

Responsibilities

• 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 deliver the right solutions for 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 constructive feedback

• Debug and resolve production issues as part of the shared on-call rotation
  

Preferred Experience

• 4+ years of professional software development experience

• Full-stack experience (React, Django)

• Strong knowledge of API design and integrations (REST, GraphQL, or similar)

• Strong understanding of database systems (schema design, query optimization, data modeling)

• Familiarity with cloud infrastructure (AWS, GCP, or Azure)

• Comfort working in fast-paced, product-driven startup environments

• Proactive, ownership-driven mindset — you enjoy taking projects from concept to completion

• Excellent collaboration and communication skills
  

Why Join TestBox

• Build foundational, greenfield systems from day one and make a significant impact

• Solve challenging UI/UX problems for a technical user base

• Define frontend architecture and best practices that will shape the company’s product long-term

• Join a company obsessed with customer experience, speed, and scale

Benefits

• Generous equity package for meaningful ownership

• Dedicated career development support

• Flexible, unlimited PTO with minimum recharge expectation

• Mental health benefits

• Fitness and learning allowances

• Remote and office setup support for a productive work environment

90-Day Plan

Weeks 1-2: Onboarding & Meet the Team

• Join onboarding sessions to learn about the company and your role

• Familiarize yourself with documentation

• Schedule time to meet team members and understand workflows

Weeks 3-4: Learn the App & Infrastructure

• Deep dive into our app and supporting systems

• Participate in team meetings and start integrating into your role
  

Weeks 5-8: Shadowing Peers

• Work closely with peers on tickets

• Learn approaches, best practices, and day-to-day processes

Weeks 9-10: First Assignments with Pairing

• Partner with Product on your first assignments

• Work closely with peers to ensure successful completion
  

Weeks 11-12: Independent Assignments

• Take full ownership of a new assignment end-to-end

• Collaborate with your team for support as needed

• Begin full participation in cycle planning and projects