Senior Software Engineer - Frontend/React

🏢 About Close

Since 2013, Close has been developing a CRM designed to streamline sales processes and boost team efficiency. They are now integrating AI into every aspect of their platform to automate routine tasks, enabling sales teams to focus on selling. Close is a bootstrapped and profitable company with a 120-person, 100% remote team, dedicated to helping small and scaling businesses succeed in sales.

🎯 The Role

As a Senior Software Engineer specializing in Frontend/React, you will be instrumental in building the user interfaces for Close's innovative AI-powered CRM. You'll have the opportunity to work across various teams, focusing on areas like AI agent interfaces, real-time communication features (calls, transcripts), core CRM surfaces (lead pages, pipelines), or growth-focused elements (onboarding, billing). This role emphasizes shipping impactful features quickly, iterating based on data, and maintaining high UI/UX standards.

🛠️ Tech Stack

The frontend is a single-page TypeScript web application built with React, bundled using Vite, and targeting modern browsers. Testing is conducted with Vitest, React Testing Library, Playwright, and Chromatic for visual regression. The UI leverages WebSockets and WebRTC for real-time updates, is styled with CSS modules, and optimized for performance with route-based code splitting and skeleton UI. Close also maintains its own design system documented in Storybook. The frontend interacts with REST API and GraphQL endpoints, backed by a Python/Flask/FastAPI, MongoDB, Postgres, and Elasticsearch stack on AWS.

💼 What You'll Do

• Build intuitive UI that integrates AI capabilities for Close customers, including creation, configuration, conversational interfaces, and observability surfaces for AI agents.
• Develop and own real-time communication UI for calls, live transcripts, coaching views, and power dialing flows using WebRTC and WebSockets.
• Create and enhance core CRM surfaces such as lead pages, pipeline views, smart search, and activity feeds, incorporating AI-powered features.
• Design and implement user-facing elements for growth, including onboarding flows, activation moments, billing, checkout UI, and import experiences.
• Collaborate closely with Product throughout the design process, from wireframes to Figma and into code.
• Work in a hypothesis-driven, experiment-first environment, shipping features rapidly, measuring impact, and iterating.

✅ What You'll Need

• Proven experience as a seasoned frontend engineer, with strong proficiency in React. Experience with other frameworks like Vue, Svelte, or Solid is a plus.
• Ability to select the most appropriate tool for a given problem.
• Demonstrated experience building and shipping LLM-backed features for real users, with a clear understanding of their strengths and limitations.
• Familiarity with designing for streamed responses, uncertain states, and agent-driven UIs.
• A habit of using AI tools in your daily workflow to enhance productivity and code quality.
• A "builder first" mentality, prioritizing getting initial iterations of features to customers.
• Strong opinions on UI craft and component design, with experience building reusable systems.
• Battle-tested experience in debugging production performance regressions, managing critical component libraries, or successfully launching high-stakes releases.

🌟 Nice to Have

• Experience with Vite, Vitest, React Testing Library, Playwright, Chromatic, Storybook.
• Familiarity with WebSockets and WebRTC.
• Understanding of REST API and GraphQL integration.
• Experience with Python/Flask/FastAPI, MongoDB, Postgres, Elasticsearch, or AWS.