Senior Software Engineer, Voice AI / Backend

About the Role Join a small engineering team building voice AI agents for customer-facing workflows. You will own projects end to end, from technical design through production, across applied AI, real-time audio, and distributed systems. What You'll Do Build reliable voice AI systems, including retrieval, dynamic model routing, and testing speech transcription systems before production rollout. Design and operate distributed call scheduling systems that handle concurrent workloads, time zones, retries, race conditions, and provider limits. Extend agents across voice, messaging, and email, maintaining shared context between real-time and asynchronous interactions. Develop memory and reasoning systems that preserve context across customer workflows. Build tools that help configure agents, debug issues, and connect to CRM, calendar, and email systems. Improve tracing and resilience so teams can identify call failures and respond to issues with workers or providers. What We're Looking For At least 2 years of experience building and owning production software, including distributed systems and end-to-end product delivery. Production experience with Python, FastAPI, or TypeScript, plus PostgreSQL, Redis, or similar data stores. Experience with real-time systems, audio processing, or voice infrastructure, and with LLMs, AI models, or agentic systems in production. Knowledge of distributed systems concepts such as race conditions, load balancing, and fault tolerance, plus experience with AWS, GCP, or Azure. Familiarity with workflow orchestration or messaging tools such as Temporal, and observability tools such as OpenTelemetry or Honeycomb. Full-stack experience with tools such as React is useful. Strong software fundamentals, independent problem-solving, and a focus on customer and business outcomes are important. Technologies include Python, FastAPI, LiveKit, TypeScript, Bun, Node.js, Fastify, React, PostgreSQL, Redis, Temporal, and major cloud platforms. Compensation & Benefits Compensation is €85,000 to €160,000 annually, plus equity. Visa sponsorship is available. Location On-site in Berlin, Germany.