Senior Software Engineer – Frontend/React (USA Only, 100% Remote)

Close builds a CRM and AI-powered sales software that helps teams sell more efficiently. The Senior Software Engineer will build and improve frontend experiences in React, collaborating with Product and engineering teams across AI, communications, CRM, and growth initiatives.

Responsibilities:

• Agents. Build the UI that puts AI in the hands of Close customers. This means the creation and configuration experiences for Close's growing family of agents, the conversational interface through which users ask questions and get answers in plain language, and the observability surfaces that let customers see what their agents are doing and why. The design challenges here are genuinely new: you'll be figuring out how AI capabilities should surface in the product
• Communications. Own the UI for one of the most real-time, high-stakes surfaces in Close: calls. You'll build in-call experiences that run on WebRTC and WebSockets, live transcript and coaching views where latency visibly matters, power dialing flows built for reps making hundreds of calls a week, and the email, SMS, and scheduling surfaces that keep async outreach moving
• CRM. Build the core surfaces that salespeople and agents both depend on: lead pages, pipeline views, smart search, activity feeds. You'll make these interactions fast and delightful for humans navigating familiar patterns, while also building the AI-powered features that are making the CRM smarter
• Growth. Own the surfaces that turn someone who just signed up into a paying customer who sticks around. That means onboarding flows, activation moments, billing and checkout UI, and the import experience - the first things new users touch. You'll work in a hypothesis-driven, experiment-first environment: ship fast, measure the impact on conversion and activation, and iterate. If you like knowing whether your work moved the needle, this is the team for it

Requirements:

• A seasoned frontend engineer. React is our bread and butter, but perhaps you've worked across Vue, Svelte, or Solid
• You pick the right tool for the problem rather than retreating to what you know
• You've seen a variety of problems, can collaborate and self-direct
• You've shipped LLM-backed features for real users and have a POV on where they're trustworthy, where they fall over, and how to make them feel reliable when customers bet their workflow on the output
• You know how to design for streamed responses, uncertain states, and agent-driven UIs
• You use AI tools in your own workflow to ship faster, write tighter code, and reason about unfamiliar parts of the codebase
• You've built reusable systems that other engineers loved using, and you think about who's on the other end — sales reps in the middle of a call, power users who live in the keyboard, and customers who just need it to work
• You've debugged performance regressions in production, owned a component library everyone else relied on, or shipped a high-stakes release where the UX had to be right under real customer pressure