Sr. Software Engineer, X Money

X.ai; Greater London; On-site; GBP 107,000 - 262,000; Full time

Benefits offered by this job

Equity

Healthcare

Dental coverage

Cash plan

Income protection

Life insurance

Discounts and perks

Job summary

SpaceXSI is seeking a Sr. Software Engineer for the X Money team to build a global payments platform serving hundreds of millions of users. You will design scalable backend services and contribute across payments, fraud, and compliance initiatives in a fast-paced, startup-like environment.

You will collaborate with iOS, Android and web engineers, lead architecture decisions, and ensure reliability and security across high-concurrency systems while delivering high-impact financial products.

Qualifications

• 5+ years of experience working on large-scale consumer applications or as a founding engineer in startups.
• Experience with high-volume streaming systems is preferred.
• Distributed systems experience for high-scale, low-latency environments.
• 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 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 dashboards, content delivery, interactive tools, 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.

Skills

Large-scale apps

Founding engineer

AI solutions

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

Base salary is just one part of our total rewards package at SpaceXSI, which also includes equity, comprehensive healthcare and dental coverage, cash plan, income protection, life insurance, and various other discounts and perks.

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