Sr. Software Engineer, Ads Product

xAI•Palo Alto, CA

About The Position

SpaceXSI is building Super Intelligence and its suite of applications, including X. X Ads is a high-impact product area operating at massive scale and being rebuilt with modern infrastructure and AI. The Sr. Software Engineer will help transform the X Ads Platform using SpaceXSI's infrastructure and AI capabilities, working across product, backend systems, infrastructure, and AI-powered features that affect a significant part of X's revenue. The role is suited to engineers who learn quickly, take ownership, and want to ship products and systems at scale. Deep advertising experience is not required, but interest in learning about large-scale advertising systems and using AI to improve ads is expected.

Requirements

At least 5 years of experience building software through internships, projects, research, open-source work, startups, or full-time roles.

Nice To Haves

Strong software engineering fundamentals.
Ability to write clean, maintainable code and learn new codebases quickly.
Strong problem-solving skills and comfort working through ambiguity.
Interest in backend systems, distributed systems, data pipelines, product engineering, or AI applications.
A bias toward action, with an interest in shipping, learning from real users, and improving quickly.
Strong ownership mindset and willingness to take responsibility for meaningful parts of the product.
Excitement about building high-quality product experiences for advertisers and users.
Experience with ads, recommendations, search, ranking, marketplaces, payments, analytics, or growth systems.
Experience working with large-scale backend systems or data processing pipelines.
Experience with React, Golang, Python, Rust, gRPC, Java, or Scala.
Experience with machine learning, LLMs, experimentation, ranking, or optimization systems.
Prior startup, research, internship, or high-impact project experience.

Responsibilities

Build and ship product features across the X Ads Platform.
Work on systems related to ad delivery, targeting, optimization, measurement, and advertiser experience.
Use SpaceXSI's infrastructure and AI capabilities to improve advertising product performance and quality.
Contribute to reliable, fast, and scalable distributed systems.
Collaborate with engineers, product leads, and cross-functional partners to turn ideas into working products.
Learn quickly, take ownership, and operate in a fast-moving environment where high-quality execution matters.
Debug, maintain, and improve production systems serving users and driving business impact.