Senior Software Engineer, Full-Stack

United States Digital Space LLC; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Equity

Mobile phone stipend

Generous vacation policy

Job summary

United States Digital Space LLC in London is seeking a skilled software engineer to design, build, and maintain backend services and APIs for a multi-tenant SaaS platform. You will own the data layer with PostgreSQL, work across a large codebase, and contribute to frontend tasks when needed.

Ideal candidates have 4–8 years of experience, strong SQL, Docker and AWS, and proficiency in Ruby, Python, or Java. Experience with RSpec testing and AI tooling is a plus.

Qualifications

• 4–8 years of professional software development experience.
• Proficient in SQL, with strong PostgreSQL experience.
• Experience with Docker or containerisation.
• Proficient in at least one major language (Ruby, Python, or Java).
• Experience with AWS cloud.
• Experience using AI tools in the development lifecycle.
• RSpec testing experience.

Responsibilities

• Design, build, and maintain backend services and APIs, with frontend work when needed.
• Work across a multi-tenant SaaS codebase for enterprise customers.
• Own data layer, schema design, and query performance (PostgreSQL focus).
• Write and maintain tests using RSpec.
• Package and deploy services with Docker in AWS cloud.
• Automate repetitive tasks and support data migrations.
• Instrument systems with logging, metrics, and tracing for observability.
• Collaborate with product managers, designers, and engineers.

Skills

Full-stack development

SQL fundamentals

Docker

Git

Ruby/Python/Java

AWS

AI tooling

Tools

PostgreSQL

Job description

At the company, we’re building a world where value moves like information does today. It’s big, it’s bold, and we’re already doing it. Through our crypto solutions for financial institutions, businesses, governments and developers, we are improving the global financial system and creating greater economic fairness and opportunity for more people, in more places around the world. And we get to do the best work of our career and grow our skills surrounded by colleagues who have our backs.

If you’re ready to see your impact and unlock incredible career growth opportunities, join us, and build real world value.

About the Cash Forecasting team:

Cash Forecasting

is our AI-amplified treasury solution that helps CFOs and treasury teams move beyond error-prone spreadsheets to achieve real-time cash visibility and predictive accuracy.

The platform integrates seamlessly with major ERPs and banking systems to automatically capture, categorise, and analyse transactional data across multiple currencies and business units. Leveraging our proprietary GSmart AI technology, the solution continuously learns from historical cash flows, sales data, and treasury information to automatically select optimal forecasting algorithms and improve accuracy by over 30%.

You’ll work on sophisticated Ruby on Rails and React software that turns diverse financial data into clear analysis, giving customers sharp insight and forecasting through intuitive dashboards. This is a critical platform moving over $100 billion in daily cash flow for enterprise customers across 40+ countries, built to hold enterprise-grade security and scalability at that scale, every single day.

What You’ll Do:

• Design, build, and maintain backend services and APIs that power the Cash Forecasting platform, while remaining comfortable picking up frontend work when the task calls for it

• Work across a large, sophisticated, multi-tenant SaaS codebase, writing code that's built to scale across enterprise customers and their data

• Own the data layer, schema design, query performance, and data integrity - with a strong emphasis on PostgreSQL and SQL more broadly

• Write and maintain thorough test coverage using RSpec, treating testing as a first‑class part of delivery

• Package and deploy services using Docker, and work within our AWS-based cloud infrastructure

• Write scripts and tooling to automate repetitive work, support data migrations, and keep the team moving quickly

• Instrument the systems you build with strong observability practices -logging, metrics, and tracing — to catch and resolve issues before they impact customers

• Benchmark and profile code to identify performance bottlenecks, and make evidence‑based decisions about where to optimise

• Collaborate closely with product managers, designers, and fellow engineers to translate business and customer needs into robust technical solutions

• Participate in code reviews and technical design discussions, contributing to the team's overall growth and improvement

• Be a champion of the YBIYRI ethos (you-build-it-you-run-it), which includes participating in the on‑call pager rotation

What You'll Bring:

• 4-8 years of professional software development experience, ideally including full-stack work with a backend lean

• Strong SQL fundamentals; hands‑on experience with PostgreSQL ideal

• Comfortable working within large, sophisticated, existing codebases and making changes safely

• Scripting ability for automation and tooling (language‑agnostic)

• Experience with Docker or other containerisation technologies

• Proven Git proficiency, including collaborative branching workflows

• Proficiency in at least one major programming language (such as Ruby, Python, or Java)

• Experience employing AI tools throughout the development lifecycle to speed up problem‑solving and delivery

• Experience testing with RSpec

Preferred Knowledge / Experience:

• Experience with Ruby or Ruby on Rails is a strong plus - while we value the ability to learn quickly across languages, familiarity with our primary stack will help you ramp up faster.

• Frontend experience, ideally with React, and the ability to contribute there when needed

• Experience with, or solid understanding of, AWS

• Experience building or maintaining multi‑tenant, enterprise SaaS platforms

• Familiarity with observability tooling and practices (logging, metrics, tracing, alerting)

• Experience benchmarking and profiling code for performance

• Experience in the financial industry, particularly treasury, payments, FX, or ERP systems

WHO WE ARE:

• The opportunity to build in a fast‑paced start‑up environment with experienced industry leaders

• A learning environment where you can dive deep into the latest technologies and make an impact. A professional development budget to support other modes of learning.

• Thrive in an environment where no matter what race, ethnicity, gender, origin, or culture they identify with, every employee is a respected, valued, and empowered part of the team.

• In‑office collaboration for moments that matter is important to our culture, and we give managers and teams the flexibility to decide which 10+ days a month they come in.

• Bi‑weekly all-company meeting - business updates and ask me anything style discussion with our Leadership Team

• We come together for moments that matter which include team offsites, team bonding activities, happy hours and more!

Take Control of Your Finances

• Competitive salary, bonuses, and equity

• Competitive benefits that cover physical and mental healthcare, retirement, family forming, and family support

• Employee giving match

• Mobile phone stipend

Take Care of Yourself

• R&R days so you can rest and recharge

• Generous wellness reimbursement and weekly onsite & virtual programming

• Generous vacation policy - work with your manager to take time off when you need it

• Industry‑leading parental leave policies. Family planning benefits.

• Catered lunches, fully-stocked kitchens with premium snacks/beverages, and plenty of fun events

*Benefits listed above are for full‑time employees.*

*the company is an Equal Opportunity Employer. We’re committed to building a diverse and inclusive team. We do not discriminate against qualified employees or applicants because of race, color, religion, gender identity, sex, sexual identity, pregnancy, national origin, ancestry, citizenship, age, marital status, physical disability, mental disability, medical condition, military status, or any other characteristic protected by local law or ordinance.*

*Please find our UK/EU Applicant Privacy Notice and our California Applicant Privacy Notice for reference.*