Senior Full-Stack Engineer (Frontend Focus)

TestBox

  • San Francisco, CA
  • Permanent
  • Full-time
  • 1 month ago
​​ Onsite — San Francisco$180,000 USD + Equity & BenefitsAbout TestBoxTestBox 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 OverviewWe are hiring a Senior Full-Stack Engineer with a strong Frontend focus to build the user-facing interfaces for our next-generation platform. This is a unique opportunity to own the creation of sophisticated, interactive tools that will be the primary authoring environment for our most technical users.You will be responsible for translating complex backend capabilities into intuitive and powerful user experiences. The core challenge is to build rich, data-intensive applications that allow users to manage complex data and automate intricate workflows, making difficult tasks feel simple and elegant. While your primary focus and expertise will be on the frontend, you will be comfortable diving into our Python/Django backend to build the APIs needed to bring your UIs to life.What You'll Do
  • Build the rich, interactive user interfaces for our platform's core authoring tools, including tools for visual workflow creation and data management and visualization.
  • Design, build, and modify API endpoints in our Django backend to support new user interfaces and ensure seamless data flow.
  • Partner closely with product design to iterate on prototypes and deliver polished, high-quality user experiences.
  • Establish the foundation for our frontend architecture, including our component library, state management strategy, and testing best practices.
  • Collaborate with backend engineers on the Platform team to define and integrate with core platform services.
Who You Are
  • You are a product-focused engineer who deeply values user experience and cares about the "why" behind what you're building.
  • You excel at turning complex problems into simple, elegant user interfaces.
  • You have a strong eye for design and a high bar for UI polish and interaction details.
  • You thrive in a collaborative environment and are skilled at bridging the gap between frontend and backend development.
  • You have a high sense of ownership and are excited by the accountability that comes with building features end-to-end.
Preferred Experience
  • 5+ years of experience in software engineering, with a proven track record of building complex web applications.
  • Deep expertise in a modern frontend framework (e.g., React, Vue, Svelte, etc.) and its ecosystem.
  • Proficiency with backend development, preferably with Python and Django.
  • Experience designing, building, and consuming REST APIs.
  • Bonus: Experience with data visualization libraries (e.g., D3.js) or building interactive, canvas-based interfaces.
  • Bonus: Experience working on developer tools or B2B SaaS products designed for technical users.
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.

TestBox