Senior Software Engineer, Voice AI / Backend

About the Role Join a small, high-velocity engineering team building voice AI agents for customer-facing workflows. You will own projects end to end, from product decisions and system design to production code, across applied AI, real-time audio, and distributed systems. What You'll Do Build reliable voice AI systems, including retrieval-augmented generation, dynamic language model routing, and testing new transcription systems before release. Design and operate distributed call scheduling systems that handle concurrency, time zones, retries, provider limits, and failure recovery. Extend agents across voice and other communication channels, maintaining shared context between real-time and asynchronous interactions. Develop memory and reasoning systems that help agents retain context across customer workflows. Build AI tools that configure agents, diagnose issues, and connect with customer relationship management systems, calendars, and email. Improve tracing and observability so production issues can be diagnosed and resolved effectively. What We're Looking For Production experience building and owning distributed systems, with strong software fundamentals and a track record of delivering projects end to end. Experience as a product engineer building customer-facing systems, rather than working exclusively in machine learning or data roles. Production experience with Python, FastAPI, or TypeScript, and with PostgreSQL, Redis, or similar data stores. Experience with real-time systems, audio processing, or voice infrastructure, as well as distributed systems challenges such as concurrency and fault tolerance. Experience with language models, AI agents, or similar systems in production, and cloud infrastructure such as AWS, GCP, or Azure. Familiarity with tools such as LiveKit, Temporal, message queues, React, and OpenTelemetry is useful. The broader stack includes Bun, Node.js, Fastify, and observability platforms. Independent, action-oriented approach, sound judgment about code quality and reliability, and a focus on team and business outcomes. Compensation & Benefits Annual compensation is €85,000 to €160,000, plus equity. Visa sponsorship is available. Location On-site in Berlin, Germany. Relocation support is available.