Member of Technical Staff - Mid-training

xAI|31 Oct 2025

fulltimeonsite

Job Description

SpaceXAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge. Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity. We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company’s mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important. All employees are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates.

RESPONSIBILITIES:

Scale synthetic coding data to trillions of tokens with large-scale docker verification.
Distill the intelligence of flagship models into flash models through synthetic data generation.
Optimize mid-training data mixtures to boost the ceiling for RL.
Engineer long-context data recipes.
Develop robust and diverse evaluation for mid-training checkpoints.

BASIC QUALIFICATIONS:

Expertise in ML and large model scaling, with familiarity across all kinds of scaling laws.
Strong ability to design ML experiments.
Familiarity with state-of-the-art techniques for curating AI training data for text, image, audio, and video modalities.
Strong engineering abilities in Spark, Ray, and other frameworks for large-scale data processing.

COMPENSATION AND BENEFITS:

$180,000 - $440,000 USD

Base salary is just one part of our total rewards package at SpaceXAI, 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.

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