Senior Software Engineer - Backend (USA Only - 100% Remote)

Stack

Responsibilities

• ▹Agents team: build Close's agentic platform and customer-facing AI experiences (Voice Agents, Custom Agents, Ask Chloe), including APIs and an MCP surface for external agents like Claude and ChatGPT
• ▹Communications team: own voice, SMS, and email infrastructure (Twilio, WebRTC, WebSockets, AssemblyAI, ElevenLabs) and build conversational AI agents
• ▹CRM team: build the structured context layer both humans and agents depend on, rebuilding the data model on MongoDB/Elasticsearch
• ▹Growth team: run experiments and own billing infrastructure (Stripe metered billing, AI credit top-ups, agentic onboarding)

Requirements

• ▹A seasoned engineer, primarily Python, perhaps with Go, Rust, or TypeScript experience
• ▹Experience shipping LLM-backed features for real users (using tools like Pydantic, Temporal, LangFuse)
• ▹Uses AI tools daily in the workflow (Claude Code, Codex, company-funded)
• ▹A builder-first mindset: ships fast rather than over-polishing a PR
• ▹Opinionated about API design for modern software (apps, agents, and humans alike)
• ▹Battle-tested: debugged latency incidents, owned a critical system, carried a pager

Soft skills

What we offer

• ▹Competitive pay plus an organization-wide goal-based bonus
• ▹~5 weeks of PTO to start, 1-week winter break, paid US holidays, +2 extra days per year of tenure
• ▹80% work option
• ▹Paid parental leave
• ▹A 1-month paid sabbatical every 5 years
• ▹Healthcare for US residents, with 99% of premium covered
• ▹401k with company match up to 6%, vested immediately

About the company

Since 2013, Close has been building a CRM. The backend runs Python Flask with a TaskTiger scheduler, MongoDB/PostgreSQL/Elasticsearch/Redis data stores, on AWS (EKS, MSK, RDS, ElastiCache, EC2), automated with Terraform and Ansible. Close is a 120-person, 100% remote, bootstrapped and profitable team.