SDE 4 - Voice

Why this role exists

JustCall is hiring an SDE 4 (Senior Software Engineer, Voice AI) in Noida or Bangalore to build and scale the real-time voice AI infrastructure powering AI voice agents for 6,000+ businesses across 70+ countries.

This is a senior individual contributor role for an engineer who has built and shipped production-grade real-time systems and understands the complexities of voice, streaming and conversational AI. You'll own the architecture and engineering of low-latency voice pipelines, ensuring AI agents can listen, respond and interact naturally over live calls.

We're looking for someone who combines strong backend engineering with hands-on experience in voice AI, distributed systems and real-time communication.

What you'll actually do

• Build real-time voice pipelines: Design and scale streaming ASR, LLM and TTS pipelines, optimising response time, throughput and reliability.

• Own conversational intelligence: Build voice activity detection, turn-taking, endpointing and interruption handling to make conversations natural and responsive.

• Engineer real-time communication: Build and optimise audio streaming systems using WebRTC, WebSockets, SIP and media servers.

• Develop AI agent orchestration: Implement LLM integrations, tool calling, conversation state, context management and fallback mechanisms.

• Optimise voice performance: Reduce end-to-end latency, improve audio quality and optimise infrastructure and model costs.

• Build evaluation frameworks: Measure speech accuracy, response latency, call quality and task completion to continuously improve agent performance.

• Scale production systems: Build reliable, highly concurrent services with appropriate monitoring, observability and fault-tolerance mechanisms.

• Drive technical ownership: Lead architecture decisions, conduct design reviews, mentor engineers and take ownership of systems from design to production.

Your work will directly shape how natural, responsive and reliable JustCall's AI voice agents are. You'll solve some of the hardest challenges in real-time AI, where latency, conversation quality and system reliability directly impact customer experience.

What we're looking for

• 8+ years of software engineering experience, with meaningful hands-on experience building production-grade real-time or Voice AI systems.

• Strong programming skills in Python or Go, with a deep understanding of asynchronous programming, concurrency and backend architecture.

• Hands-on experience building real-time streaming systems using WebSockets, WebRTC or gRPC.

• Experience working with streaming ASR, LLM and TTS systems, including integrating and optimising speech and language model providers.

• Strong understanding of voice fundamentals, including audio streaming, VAD, endpointing, turn-taking and interruption handling.

• Experience with telephony protocols such as SIP, RTP and WebRTC, and debugging real-time media issues.

• Strong understanding of distributed systems, system design, scalability and fault tolerance.

• Experience building and operating highly available backend services in production.

• Familiarity with AWS/GCP, Docker, Kubernetes and observability tools.

• Ability to own architecture, drive technical decisions and mentor engineers without formal authority.

Edges that help

• Experience building production Voice AI agents or conversational AI products.

• Hands-on experience with frameworks such as LiveKit, Pipecat, Vocode or similar.

• Experience with telephony platforms, CPaaS providers, SIP infrastructure or media servers.

• Exposure to speech processing, audio DSP, noise suppression or speaker diarization.

• Experience with self-hosted model serving and inference optimisation.

• Experience building automated evaluation frameworks for voice agents.

• Familiarity with contact-centre platforms, IVR, dialers or CCaaS products.

How we work

• Small teams, real ownership: Own systems end-to-end, from architecture to production.

• Ship and measure: Use latency, quality and reliability metrics to drive engineering decisions.

• Engineering-first: Focus on solving complex problems, writing clean code and building for scale.

• Write it down: Design documents and technical reviews guide how we build.

• Work where the work is: Based in Noida or Bangalore, working closely with product and engineering teams.

• Pay for impact: Market-benchmarked fixed pay with variable and equity as JustCall scales toward $100M ARR.

The bigger picture

JustCall is SaaS Labs' flagship product, used by 6,000+ businesses across 70+ countries to run their customer conversations. Backed by Peak XV and Base10 Partners, we've crossed $40M ARR and are building toward $100M.

If building the next generation of AI-powered conversations excites you, let's talk.

SaaS Labs is an equal opportunity employer. We believe diverse teams build better products and make employment decisions without discrimination based on race, colour, religion, national origin, age, sex, marital status, ancestry, disability, genetic information, veteran status, gender identity, sexual orientation or any other protected characteristic.