Senior Backend Engineer (Series A Backed)

Phonely
San Francisco
Workplace: OnsiteFull timeUSD 180,000 - 230,000 annuallyFunction: Software EngineeringExperience: 5+ yearsSkills: ["Python","Asyncio","LLMs","APIs","Security","Testing","CI/CD","AWS","Kubernetes","Datadog","Redis","SQL","NoSQL","Firebase","Supabase","Next.js","SIP"]

Senior Backend Engineer to build Python-based state systems for real-time voice AI, integrating multiple LLM providers, and designing microservices with AWS, Kubernetes, and modern backend tooling. You will write high-performance Python, tests, and contribute to secure, scalable infrastructure in San Francisco.

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FursaFursa
Phonely
Phonely
4 months ago

Senior Backend Engineer (Series A Backed)

✓ Verified Job

Canonical indexed version, validated from employer's careers page.

Source: Company careers pageValidated by: Fursa AI
Last checked: 12 hours agoStatus: Live

Job Summary

Senior Backend Engineer to build Python-based state systems for real-time voice AI, integrating multiple LLM providers, and designing microservices with AWS, Kubernetes, and modern backend tooling. You will write high-performance Python, tests, and contribute to secure, scalable infrastructure in San Francisco.
Location: San Francisco
Workplace: Onsite
Employment Type: Full time
Job Function: Software Engineering
Seniority: Sr. Manager level

Key Responsibilities

  • •Build and maintain Python-based state systems that drive voice AI in real-time conversations.
  • •Integrate and orchestrate multiple LLM providers, including prompt design, tool/function calling, routing, and fallbacks.
  • •Write clean, maintainable, high-performance Python code using asyncio and OOP, with best practices.
  • •Write automated tests and validation suites to ensure correctness, resilience, and safe iteration of agent logic and state transitions.
  • •Monitor production systems, debug agent behavior, and continuously improve reliability and conversation quality.

Pay and Benefits

Salary: USD 180,000 - 230,000 annually
Equity and Bonus:Equity

Key Requirements

  • •5+ years writing Python, experience writing async web apps using FastAPI and testing frameworks
  • •Understanding of LLMs, APIs, Cloud, CI/CD pipelines
  • •Understanding of technical specifications and good architecture
  • •Strong technical and communication skills
  • •Experience with AWS & Kubernetes
Experience:5+ yearsVoice AISaasCloudWeb services
Skills:PythonAsyncioLLMsAPIsSecurityTestingCI/CDAWSKubernetesDatadogRedisSQLNoSQLFirebaseSupabaseNext.jsSIP
Tech Stack:PythonAsyncioAWSKubernetesRedisFirebaseSupabaseNext.jsDatadogSIPReal-timeLLMsCI/CD

Eligibility

Visa:US citizen/visa only
Work Authorization:Authorization required. Sponsorship not provided.

Company Brief

Phonely
Develops AI-driven voice agents that automate phone conversations for businesses, handling customer support, lead qualification, and sales outreach. Their platform uses natural language understanding and speech synthesis to conduct human-like calls and integrate with CRM systems.
Industry: AI & Machine Learning
Website