Senior Backend Engineer - Payments

United States Digital Space LLC; United States; Hybrid; USD 140,000 - 190,000; Full time

Benefits offered by this job

Company card ownership

Lunch allowance

Private healthcare

25 days holiday

Hybrid/remote options

AI tooling support

Parental leave

Job summary

United States Digital Space LLC is seeking a Senior Backend Engineer for the Bank Infrastructure team. You’ll build and maintain payment rails, ensuring accurate, scalable transfers with strong resilience and bank integrations.

We value transparency, collaboration, and engineering excellence, with hybrid and remote options. You will mentor peers and drive high-impact improvements across payment flows and systems.

Qualifications

• Experience building payment integrations with banks or payment networks.
• Strong knowledge of end-to-end payment flows and settlement processes.
• Experience operating highly available distributed systems with failure recovery.

Responsibilities

• Design, build, and maintain bank integrations and payment partner connections.
• Own reliability and correctness of payment flows including reconciliation.
• Architect resilient systems and improve observability and operational excellence.
• Collaborate with compliance, finance operations, and product teams.
• Mentor other engineers and address technical debt proactively.

Skills

Payment integrations

Bank APIs

Distributed systems

Kotlin/Java

PostgreSQL

AWS

Kubernetes

Observability

AI tooling familiarity

Mentorship

Education

Bachelor's degree in CS/related field

Tools

Grafana

PostgreSQL

AWS

Kubernetes

Job description

About the company

Messy spend management is tricky business. And tedious processes are a lose-lose situation for all involved, not just finance. At the company, we're changing that. We build spend solutions that make managing money seamless, empowering, and surprisingly effective for finance teams and employees alike - with a vision to help all businesses ‘go beyond’.

The word ‘the company’ actually means ‘more than you’d expect’, and living by that mantra has been the secret to our success over the last 10 years.

Now, we’re at a pivotal moment in our journey; every move we make has a direct impact on our 40,000+ customers, our business, and our collective success. We need people who take pride in uncovering customer needs, who turn complex problems into simple solutions, challenge the way things are done (respectfully), and always aim high. With great ambitions driving us forward, we can’t say we’ve got this whole thing figured out. And frankly, that’s half the fun! What we can say is that we’re a driven, progressive, and, importantly, a kind bunch of 850+ people from over 100 nationalities, all committed to delivering the future of business spending, together.

About the role

We're looking for a Senior Backend Engineer to join our Bank Infrastructure team at the company. This team builds and maintains the payment rails that power the company's money movement, integrating with banks and payment partners to handle inbound and outbound bank transfers reliably and at scale. You'll be working on some of the most critical systems at the company: the infrastructure that guarantees that each financial transaction, whether incoming, outgoing, or internal, is processed and settled with absolute accuracy, on time, and with the resilience to recover gracefully when things go wrong.

If you're excited by the challenge of building highly reliable financial systems and want to work in a culture that values transparency, collaboration, and engineering excellence, this role is for you.

What you’ll be doing

As a Senior Backend Engineer on Bank Infrastructure, you will:

• Design, build, and maintain integrations with banks and payment partners across multiple payment schemes (SEPA, Faster Payments, SWIFT, and others).
• Own the reliability and correctness of inbound and outbound payment flows, including reconciliation, settlement, and exception handling.
• Architect systems that are resilient to partner outages, network failures, and edge cases inherent in financial messaging.
• Lead initiatives to improve system observability, fault tolerance, and operational excellence across payment rails.
• Collaborate with cross-functional teams, including compliance, finance operations, and product to evolve the company's payment capabilities.
• Participate in code reviews, post-mortems, and provide mentorship to other engineers.
• Proactively address technical debt and guide the team through technical challenges and migrations.

What you bring

You’ll thrive in this role if you have:

• Hands-on experience building payment integrations, bank APIs, payment scheme integrations, or financial messaging formats (ISO 20022, SWIFT, SEPA, Faster Payments, or similar).
• Strong understanding of payment flows end-to-end: payment initiation, routing, reconciliation, settlement, and exception/failure handling.
• Experience designing and operating highly available, resilient distributed systems with robust error recovery and observability.
• Expertise in server-side development, ideally Kotlin or Java, with strong experience in microservices and distributed systems.
• Proficiency with relational databases (PostgreSQL), cloud environments (AWS, Kubernetes), and observability tooling (e.g. Grafana).
• Awareness of payment compliance and regulatory considerations (e.g. AML, sanctions screening, PSD2) is a plus.
• Understanding of safeguarding of customer funds and the impact of money movement pipelines.
• Strong problem-solving skills and experience owning production payment systems through incidents and operational complexity.
• High proficiency with AI-enhanced development tools (such as GitHub Copilot or Claude) as integrated partners for system design, documentation, and code generation.
• Willingness to deepen your AI fluency as the company scales AI adoption across engineering.
• We're building a culture where thoughtful AI use for delivery velocity and quality.
• Proven ability to structure complex engineering problems for AI collaboration, including writing precise specifications, validating generated outputs, and iterative development.
• A proactive drive to expand your AI fluency as we scale adoption to enhance delivery velocity and maintain high engineering quality across our organisation.
• A collaborative mindset and the ability to mentor and upskill teammates.

Who you’ll be working with and reporting to

You will report to the Engineering Manager for Bank Infrastructure and work closely with cross-functional teams spanning product, finance operations, compliance, and other engineering squads within the company's Payments organisation. Bank Infrastructure is foundational to nearly everything the company does, your work will have direct dependencies with and from Card Infrastructure, Credit, and beyond. You'll collaborate with partners across the business to shape how the company moves money reliably at scale.

How you’ll develop in this role

In your first six months at the company, you'll:

• Get deep into the company's payment rail architecture, understanding how inbound and outbound bank payment flows are built, monitored, and operated.
• Take ownership of meaningful initiatives in the bank integration or payment operations domain and drive them from design to production.
• Build relationships across the engineering organisation, contributing to code reviews and technical discussions beyond your immediate team.
• Grow your expertise in high-reliability, mission-critical financial infrastructure while contributing to the company's broader engineering culture.

Show me the benefits!

• Your own the company card (no more out-of-pocket spending!)
• Lunch is on us for your work days - enjoy catered meals or receive a lunch allowance based on your local office
• Comprehensive private healthcare - depending on your location, coverage options include Vitality, Alan or Médis
• We offer 25 days of holiday + your public holidays
• For our Team, we offer both hybrid and fully remote working options
• Option to purchase 5 additional days of holiday through a salary sacrifice
• We use MyndUp to give our employees access to free mental health and well-being support with great success so far
• Paid parental leave - we want to make sure that we're supportive of families and help you feel that you don't have to compromise your family due to work

The interview process

We want to ensure you are set-up for success and understand what will be expected of you. If your application is successful, our interview process is as follows:

• Intro call: A 30-minute chat with our Talent Partner to discuss the role and your background.
• Coding Interview (Multiple choice)
• System Design (whiteboarding session)
• Engineering Mananeer Behavioural Interview

Transparency is important to us so we also wanted to share some insights about what we’re looking for in applications to ensure you can set yourself up for success!

Last time we hired this role, we received hundreds of applicants but could only speak with so many. Some of the key reasons why previous candidates didn’t make it past the application screening stage include:

CV writing and content: we receive a lot of CVs, and many of them are AI-generated. We love seeing people leverage AI—it’s a big focus for us internally too—but without human intervention, these CVs can sometimes become generic and fail to show a candidate in the best light. What we're really looking for is the specific details of real impact that only you know from your previous experience. A top tip from us is to use the “Achieved X, as measured by Y, by doing Z” formula (credit: Laszlo Bock, ~2014) to give a really clear picture of what you’ve worked on. A final note: including links to your previous companies' websites is a huge help and allows us to truly understand your background!

Application care: every single application we receive is reviewed by a human (yes, hundreds of them) because we believe that candidates' efforts should be matched by an equal level of human care. This means that we expect a similar level of attention put into your application. Read and answer the application questions carefully, they make a huge difference in our decision-making process.

Profile to role fit: highlight most important aspects of the role, points that might get misunderstood, any specific industry requirements etc.