Lead AI Engineer (Speech / Voice)

Chrona agency; Remote; GBP 80,000 - 120,000; Full time

Job summary

A rapidly growing AI startup in London seeks a Senior Engineer to lead the development of their cutting-edge Real-Time Voice AI Agent and ML toolkit. The role involves deep technical challenges in voice technologies and applied machine learning, working directly with the CEO and CTO. Candidates should have robust engineering skills and a passion for innovation, and the position offers competitive salary, equity, and fully remote work options with a strong growth path based on project delivery.

Benefits

Competitive salary

Equity in the company

Fully remote work

Global offsites

Qualifications

• Experience in building and scaling real-time systems.
• Strong knowledge in ASR, TTS, and ML toolkit development.
• Ability to explain complex systems simply.

Responsibilities

• Lead development of real-time Voice AI Agent.
• Develop and ship models for ML applications.
• Contribute to backend development as needed.

Skills

Real-Time Voice AI development

Applied ML

Backend development (Nest.js/Node.js)

Docker

Observability tools (Prometheus, Grafana)

Strong engineering fundamentals

Tools

Docker

GitHub Actions

Postgres/Supabase

Job description

We are a YC-backed AI startup building the worlds most advanced real-time Speech AI coach used in online calls. Over the past six months, weve grown from $100k to $5M ARR, raised $2.5M from top-tier investors, and assembled a world-class engineering team (ex-Google, Nvidia, Lyft, Amazon) solving hard problems in voice, ML, and real-time infrastructure.

We are looking for a senior, hands-on engineer to lead development of our real-time Voice AI Agent and internal ML toolkit. Youll own end-to-end systems across real-time audio, applied ML, and production deployment working directly with our CEO and CTO.

What Youll Do

• Build and scale our Real-Time Voice AI Agent (LiveKit/WebRTC):
  streaming ASR/TTS, VAD, diarization, state machines, session management, latency/QoS tuning.
• Develop our ML toolkit and ship models to prod (ASR, TTS, VAD, embeddings, speaker ID).
  DSP, ffmpeg/decoding, ONNX/TensorRT, reproducible pipelines.
• Contribute to backend when needed (Nest.js/Node.js, REST/OpenAPI, Postgres/Supabase).
• Work on applied ML around LLMs: RAG, function-calling, routing, safety, A/B testing.
• Design reliable real-time systems: backpressure, retries, idempotency, batching, caching.
• Build data workflows: collection, cleaning, anonymization, synthetic data, offline/online eval.
• Own observability & SLOs: Prometheus, Grafana, Sentry, tracing, alerting.
• Deploy and operate infra: Docker, GitHub Actions, LiveKit Cloud, Modal/AWS (GPU inference).

What We Value

• Ability to move fast and deliver (high-intensity, startup mindset).
• Experience in big tech / strong VC-backed startups / Yandex / research labs.
• Any founder experience (even failed).
• Strong engineering fundamentals + taste in product & design.
• Open-source contributions, ML/algorithms background, Kaggle/CF/olympiads are a plus.
• A public presence: blog, Twitter, engineering posts bonus points.
• Clear communication and ability to explain complex systems simply.

We do not hire from outsourcing firms, Web3, or gambling.

What We Offer

• High-ownership role with direct impact on product and roadmap.
• Work directly with CEO/CTO every day.
• Competitive salary + meaningful equity (company valued at ~$20M last year).
• Fully async remote, any timezone (via Deel).
• US visa support (O-1).
• 12 global offsites per year (last one Bali).
• Clear growth path: compensation increases with delivered projects.