Member of Technical Staff, Midtraining

About xAI

xAI’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. We operate with a flat organizational structure, and all employees are expected to be hands‑on and contribute directly to the company’s mission. Leadership is given to those who show initiative and deliver consistently excellent results.

The mid‑training team at xAI aims to provide an omni model that can understand the universe through text, image, video, and audio. We are looking for expert engineers in multimodal mid‑training data.

• Python
• JAX and XLA
• Spark
• Ray

The role is based in the Bay Area (San Francisco and Palo Alto). Candidates are expected to be located near the Bay Area or open to relocation.

• Design synthetic data algorithms that push the frontiers of model intelligence.
• 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.

• 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.

After submitting your application, the team reviews your CV and statement of exceptional work. If you advance, you’ll have a 15‑minute phone interview, followed by four technical interviews: a coding assessment, two technical problem‑solving sessions, and a meet‑the‑team presentation. The entire process typically takes about one week and is conducted via Google Meet.

Annual salary range: $180,000 - $440,000 USD.

Base salary plus equity, comprehensive medical/vision/dental coverage, 401(k) retirement plan, disability and life insurance, and various discounts and perks.

xAI is an equal opportunity employer.