Sr. Software Engineer, X Money

Xai; Greater London; On-site; GBP 107,000 - 262,000; Full time

Benefits offered by this job

Equity

Healthcare

Cash plan

Income protection

Life insurance

Discounts

Job summary

SpaceXSI in the United Kingdom is seeking a Sr. Software Engineer for the X Money team to design and build a global payments platform. You will focus on backend development, microservices, and security, while collaborating with iOS, Android, and web engineers on high‑scale products.

You will contribute to greenfield projects in a startup‑like environment, shaping architecture for low-latency, high-availability systems and engaging with AI and finance initiatives.

Qualifications

• 5+ years of experience on large scale consumer apps or startups with rapid prototyping and AI solutions.
• Experience with high-volume streaming systems and distributed architectures.
• Proficiency in Rust, Go, Python, or Java.

Responsibilities

• Develop backend services, APIs, and data models for high-volume multi-user environments.
• Collaborate with iOS, Android & Web engineers to ship products.
• Design microservices for payments, transactions, growth, monetization and engagement.
• Build and maintain full-stack features including dashboards and real-time analytics.
• Assist in architecture decisions for scalability, reliability and secure data handling.
• Maintain code quality via testing, monitoring and deployment practices.

Skills

High-volume streaming systems

Distributed systems

Rust

Go

Python

Java

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.

SR. SOFTWARE ENGINEER, X MONEY. We are seeking a talented Software Engineer to join our X Money team, focused on building a revolutionary global payment network that will serve over 600 million users and rival the world's largest financial institutions. In this role, you will specialize in backend development, designing and optimizing robust microservices to ensure scalability, security, and reliability. You will support full-stack efforts, collaborate with cross-functional teams on payments, fraud detection, and compliance initiatives, and contribute to the creation of a high-scale financial products platform. This is an opportunity to work on greenfield projects in a fast-paced, startup-like environment, driving innovation at the intersection of AI and finance.

RESPONSIBILITIES

• Develop backend services, APIs, and data models to support high-volume, multi-user environments
• Work with iOS, Android & Web client engineers to ship products
• Design robust infrastructure and microservices for payments, transactions, growth, monetization, and engagement across platforms
• Build and maintain fullstack features, including user dashboards, personalized experiences, content delivery, interactive tools, assessments, and real-time analytics
• Lead architecture, scalability, and reliability decisions for high-concurrency, low-latency systems
• Uphold engineering excellence via testing, monitoring, deployment, and secure data handling

BASIC QUALIFICATIONS

• 5+ years of experience working on large scale consumer applications or early-mid stage startup experience as a founding engineer, emphasizing rapid prototyping, user-centric design, and AI solutions

PREFERRED SKILLS AND EXPERIENCE

• Experience with high-volume streaming systems
• Experience with distributed systems for high-scale, low-latency environments
• Experience with Rust, Go, Python, or Java

COMPENSATION AND BENEFITS

£107,000 - £262,000 GBP

• equity
• comprehensive healthcare and dental coverage
• cash plan
• income protection
• life insurance
• various other discounts and perks

SpaceXSI is an equal opportunity employer.

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