Senior Software Engineer - Voice AI

Role Description

Our client is a mission-driven, seed-stage startup modernizing emergency response communications, reducing 911 call wait times and improving public safety outcomes. Their core product is an AI-powered voice agent that autonomously handles incoming calls for government services, focusing on public-safety and city-service hotlines.

The platform utilizes commercially available and open-source models to provide a sophisticated voice agent capable of:

• Triaging 911 calls
• Automating routine and non-emergent 911 calls
• Handling 311 and government service calls

R&D is organized into a single cross-functional delivery team led by the co-founder and CTO. The company is seeking a senior software engineer to join their engineering team.

Key Responsibilities

• Design and implement event-driven, real-time, highly concurrent systems leveraging advanced concurrency patterns (e.g., actor model, goroutines), asynchronous messaging, and performance optimizations to ensure low-latency, high-throughput, and fault-tolerance.
• Collaborate on cloud-native architecture, infrastructure as code, CI/CD pipelines, autoscaling and load-balancing strategies, security best practices, and observability efforts.
• Integrate LLMs and other emerging AI technologies, select and potentially fine-tune models, orchestrate deployments, and monitor performance.
• Design, implement, and optimize audio-processing pipelines for capabilities such as speech-to-text, text-to-speech, voice-activity detection, endpointing, noise filtering, and emotion detection.
• Guide architecture and design decisions, conduct code reviews, establish best practices, and coach team members to accelerate their technical growth while reinforcing a culture of continuous improvement.

Tech Stack

• Back-end: Elixir (Phoenix, Membrane)
• Database: PostgreSQL
• Cloud provider: Azure
• Machine Learning & AI services: OpenAI
• Infrastructure as code / containerization: Terraform, Docker
• Monitoring, alerting & observability: New Relic, incident.io

Qualifications

• 4+ years of experience in back-end or full-stack software engineering.
• An adaptable, resilient disposition suited to a dynamic startup environment.
• Experience designing and implementing event-driven, highly concurrent systems.
• Experience with natural language processing (NLP).
• A contagious growth mindset and a persistent desire to improve yourself, the team, products, and processes in a scaling business.
• Excellent command of English.

It’s a Bonus If

• You have an acute interest in building impact-oriented technology and saving lives with software.
• You have helped build or scale an enterprise SaaS venture.
• You have designed and operated highly concurrent, fault-tolerant services using Elixir, Erlang, Go, or an equivalent language.
• You have developed and integrated voice-AI or audio-processing solutions in production.
• You have experience with telephony systems (PSTN, SIP protocols, PBX architectures).
• You have experience with WebRTC technologies (peer-to-peer media streaming, signaling protocols, ICE/STUN/TURN for NAT traversal, data channels, and client-server integration).
• You have experience with Vector databases and similarity search pipelines.