Role on Close's Communications team to build and improve infrastructure for email/calendar sync, live calling, voice agents, and streaming/event pipelines. Work involves Python/Flask backend services, real-time systems (WebRTC, WebSockets), telephony (Twilio, codecs), AI integrations (transcription and voice models), and infrastructure (Kafka, Redis, PostgreSQL, MongoDB, AWS, Docker, Kubernetes, Terraform, Ansible). Position is USA-only and fully remote.

Close is hiring a Senior Backend Engineer (USA only, 100% remote) to work on the Agents team responsible for the agent core, eval/observability, MCP surface, and orchestration for voice/chat/custom agents. The role centers on Python backend engineering, production LLM/agent features, evals and tracing, event-driven/custom agent work, and integrating deterministic workflows with non-deterministic LLM outputs. Tech touched includes Python/Flask, Temporal, LangFuse, PostgreSQL, MongoDB, Elasticsearch, Redis, AWS, Docker, and Kubernetes.

Close is hiring a Software Engineer embedded in the Support function (USA only, remote) to design and ship internal AI drafting tools, autonomous reply systems, workflow automation, reporting dashboards, and customer self-service diagnostics. The role requires 3+ years of software engineering experience, fluency in languages such as Python, Rust, Go, or TypeScript/JavaScript, and experience with information retrieval/semantic search/RAG; the engineer will work closely with Support and report to the Director of Support.

Close is hiring a Senior Software Engineer (Frontend/React) to build and maintain a TypeScript React single-page app. The role involves working with real-time technologies (WebSockets, WebRTC), testing and visual-regression tooling, a custom design system/Storybook, and integrating AI/LLM-backed features. Backend stack and services referenced include REST/GraphQL endpoints, Python (Flask/FastAPI), MongoDB, Postgres, Elasticsearch, and AWS. The position is remote and limited to candidates based in the USA.

Close is hiring a Senior Software Engineer (Backend) for a USA-only, fully remote role. The position focuses on building Python/Flask backend services, shipping LLM-backed features and agent infrastructure, and operating systems on AWS (EKS, RDS, EC2, ElastiCache, MSK). The stack includes MongoDB, PostgreSQL, Elasticsearch, Redis, Docker, Kubernetes, Terraform and Ansible. Teams include Agents, Communications, CRM and Growth; responsibilities include API design, real-time and async processing, and scaling production services.