About xAIxAI’s mission is to develop advanced AI systems that are truthful, competent, and maximally beneficial for all of humanity. This organization is for individuals who appreciate challenging themselves and thrive on curiosity.As a Hardcore Engineer on the Post-training team, you will be part of an elite group of software engineers responsible for improving frontier AI model capabilities on the most challenging software engineering problems. To accomplish this, you will build distributed systems to train large models, develop environments for agents, and build frameworks to improve model inference throughput.Hardcore engineers will get exposure and will be expected to solve and take ownership of components across the entire stack. Ideal candidates are problem solvers who can understand the problem in a scientific way and can solve the problem practically.Tech StackPythonJAXRustSparkLocationThe 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.FocusBuild distributed systems to train and evaluate modelsDevelop environments and harnesses for agentsOptimize data processing and inference frameworks for latency and throughputIdeal ExperiencesHardcore engineering skills with passion to improve different aspects of data and modelRTFM. Hardcore engineers don’t shy away from reading the source and documentationHave demonstrated exceptional work.Building bespoke data processing libraries from scratch.Designing and implementing distributed systems in Rust.Keeping up with state-of-the-art techniques for preparing AI training data.Organizing and meticulously bookkeeping data across multiple clouds, of multiple modalities, and from many sources.Interview ProcessAfter submitting your application, the team reviews your CV and statement of exceptional work. If your application passes this stage, you will be invited to a 15 minute interview (“phone interview”) during which a member of our team will ask some basic questions. If you clear the initial phone interview, you will enter the main process, which consists of four technical interviews:Coding assessment in a language of your choice.Systems hands-on: Demonstrate practical skills in a live problem-solving session.Project deep-dive: Present your past exceptional work to a small audience.Meet and greet with the wider team.Our goal is to finish the main process within one week. We don’t rely on recruiters for assessments. Every application is reviewed by a member of our technical team. All interviews will be conducted via Google Meet.Annual Salary Range$180,000 - $440,000 USDCalifornia Consumer Privacy Act (CCPA) Notice #J-18808-Ljbffr