Model Engineer, Voice

X.ai; Palo Alto (CA); On-site; USD 150,000 - 450,000; Full time

Benefits offered by this job

Equity

Medical, vision, and dental coverage

401(k) retirement plan

Short & long-term disability insurance

Life insurance

Discounts and other perks

Job summary

SpaceXSI is seeking a Model Engineer, Voice to design, build, and run the software systems behind Grok Voice, delivering multilingual, real-time spoken interactions across devices. You will own the full stack from data processing to deployment, ensuring stability, low latency, and scalability for global-scale applications.

The role emphasizes production-quality Python/C++ tooling, distributed systems, and cutting-edge frameworks like PyTorch and JAX, with a focus on robust, efficient training

Qualifications

• Bachelor's degree in computer science or engineering.
• Experience writing production-quality code in Python, PyTorch, JAX, Rust, or C++.

Responsibilities

• Design, build, and maintain large-scale distributed data pipelines for audio data used in training.
• Build and optimize distributed training infrastructure and software for speech-language models.
• Create automated evaluation and testing systems for model quality and latency.
• Integrate voice models into production applications and deploy at global scale with low latency.
• Profile and optimize system performance across training and inference.

Skills

Python

PyTorch

JAX

Rust

C++

Kubernetes

Spark

Ray

Distributed training

A/B experimentation

Education

Bachelor's degree in computer science, software engineering, computer engineering, electrical engineering, or another engineering discipline

Tools

Grok Voice infrastructure

Large-scale data pipelines

PyTorch

JAX

Job description

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today, SpaceX is actively developing the technologies to make this possible, with the ultimate goal of making life multiplanetary and expanding consciousness to the stars.
SpaceXSI is building Super Intelligence to help humanity understand the universe. Our teams are building the full Super Intelligence stack: from our Colossus supercomputers, to Grok models, to our suite of applications, including Grok Bot, Grok Build, Grok Imagine, Grok Voice, and X. We're creating a powerful flywheel where more compute trains better models, better models power more useful products, and what we learn from people using those products shapes what we build next.

MODEL ENGINEER, VOICE

You’ll join the Grok Voice Model team as a software engineer. You’ll design, build, and run the software systems behind Grok Voice, which delivers natural, low-latency, multilingual spoken interactions across devices and in real time. The team owns the full engineering stack behind the model, from large-scale data processing to distributed training to production deployment.

RESPONSIBILITIES:

• Design, build, and maintain large-scale distributed data pipelines that ingest, process, and annotate real-world and synthetic audio, so the training and evaluation systems get reliable, high-quality data
• Build and optimize the distributed training infrastructure and software for speech-language models in JAX and PyTorch, including the systems that run supervised fine-tuning and reinforcement learning at scale
• Build automated evaluation and testing systems that measure accuracy, audio quality, latency, and real-time performance, plus the experimentation infrastructure used to validate every model release
• Integrate voice models into production applications and real-time services, write the technical specifications for spoken interactions, and own deployment from prototype to global scale with a focus on stability, low latency, and reliability
• Profile and optimize system performance across training and inference, including throughput, latency, memory use, and compute efficiency

BASIC QUALIFICATIONS:

• Bachelor's degree in computer science, software engineering, computer engineering, electrical engineering, or another engineering discipline
• Experience writing production-quality code in Python, PyTorch, JAX, Rust, or C++

PREFERRED SKILLS AND EXPERIENCE:

• Experience building and running large-scale distributed training and inference systems on Kubernetes
• Expert-level Python, writing clean, efficient, production-quality code for large-scale systems
• Experience implementing and optimizing model training and inference software in JAX or PyTorch
• Experience building automated testing, evaluation, and A/B experimentation pipelines for production systems
• Hands-on experience building distributed data processing systems with tools like Spark and Ray
• A proactive, self-driven attitude and the ability to deliver in a fast-paced, high-caliber team

COMPENSATION AND BENEFITS:

$150,000 - $450,000 USD

Base salary is just one part of our total rewards package at SpaceXSI, which also includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks.

SpaceXSI is an equal opportunity employer. For details on data processing, view our Recruitment Privacy Notice.