Senior Backend Engineer — High-Scale Payments & AI Platform

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

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.