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Software Engineer, Horizon

Sierra· Engineering
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San Francisco, CA$230k - $390kFull-timePosted 3w ago

About the role

Software Engineer role focused on building and scaling long-horizon AI agents and platform infrastructure for Horizon, with responsibilities spanning end-to-end system design, multi-channel engagement, and shaping product architecture.

Responsibilities

  • Build primitives for self improvement: feedback loops, evaluation systems, memory, signals, and decisioning infrastructure for long-running agents.
  • Build the future of long-horizon agents: design and ship agents that pursue complex business outcomes over days, weeks, or months across voice, SMS, email, and other channels.
  • Turn 0-to-1 work into a platform: identify patterns and build reusable systems, abstractions, and tools for faster Horizon agent launches.
  • Solve technically complex problems: work across orchestration, integrations, data, memory, signals, decisioning, observability, and multi-channel engagement.
  • Shape the Horizon product: surface platform gaps and help define Horizon’s architecture and roadmap.
  • Create a clean path beyond the POC: translate validated solutions into durable product capabilities and enable continued deployment

Qualifications

  • Experience building and scaling end-to-end production systems.
  • Strong platform and systems engineering fundamentals.
  • Ability to move between customer problems, product design, and technical implementation.
  • Strong technical judgment in ambiguous, fast-changing environments.
  • Builder’s mindset to take products from zero to one.
  • Comfort working directly with customers and understanding complex business processes.
  • High agency, adaptability, and clear communication.
  • At least two years of professional software engineering experience
  • Experience with Python, TypeScript, or Go and React.

Skills

Required:end-to-end production systemsPythonTypeScriptReact
Nice to have:Go

Benefits

  • Flexible (unlimited) paid time off
  • Medical, dental, and vision benefits for you and your family
  • Life insurance and disability benefits
  • Retirement plan dependent on country of employment
  • Parental leave
  • Fertility and family building benefits through Carrot
  • Lunch, snacks and coffee
  • Discretionary benefit stipend
  • Free alphorn lessons
Last updated Oct 21, 2026. Interested? Apply on the company site.
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About Sierra

Better customer experiences. Built on Sierra.

Sierra helps businesses build better, more human customer experiences with AI.

AICustomer ExperienceCustomer SupportVoiceai-agents-and-applicationsorchestrationvoice-ai-stackwing-list-2026
Company profileWebsite

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