Developer Platform Engineer

About Us

Equals Money is a leading payments and financial operations platform helping businesses simplify, control, and optimise their money movement. With more than a million customers served over 18 years, our award-winning portfolio spans travel money, international transfers, card issuing, FX hedging, and expense management.

In May 2025, Equals Money and Railsr came together to form a single, more powerful fintech. The merger unlocks a rare moment: we have the scale, regulatory foundation, and infrastructure of an established business, combined with the urgency, complexity, and ambition of a high-growth company rebuilding its operating model for the next decade.

To deliver on this vision, we are transforming how our business works from the inside out. We are building integrated systems, automated workflows, and AI-enabled processes that will power faster onboarding, stronger compliance, better decision-making, and rapid international expansion.

About the Role

Equals Money is building the infrastructure that lets businesses move money with confidence. Our APIs are at the heart of that - and right now they’re not as easy to integrate with as they should be.

We’re hiring a Developer Platform Engineer to own that. This is a hands-on, high-ownership role sitting at the intersection of engineering and external developer experience. You’ll build and own the developer sandbox - a production-grade environment where external developers can integrate, test, and ship - and you’ll shape everything around it: the APIs, the documentation, the tooling, and the feedback loop back into our engineering teams.

This isn’t a documentation role. We’re looking for someone who writes production code, makes opinionated decisions about how our platform should work, and can represent Equals Money’s APIs

to the world.

Requirements

What You’ll Own

The Developer Sandbox (Primary Ownership)

The sandbox is your core product. You’re accountable for making it best-in-class - not just functional, but genuinely useful for developers building real integrations. That means:

• Designing and building a production-parity sandbox environment that external developers can rely on

• Owning the full lifecycle: architecture, deployment, reliability, and continuous improvement

• Making it the gold standard by which external developers judge Equals Money’s platform

• Ensuring it surfaces realistic data, simulates edge cases, and removes friction from day one of integration

Developer MCP Server

Equals Money is investing in AI-native developer tooling. You'll own the externally facing MCP (Model Context Protocol) server - the interface that lets AI assistants and agentic tools integrate directly with our platform. That means:

• Owning the full lifecycle of the MCP server: design, implementation, deployment, and ongoing reliability

• Ensuring the server exposes well-structured, discoverable tools that make Equals Money’s APIs accessible to AI agents and developer tooling

• Collaborating with internal engineering teams to surface new capabilities through the MCP interface as the platform evolves

• Monitoring adoption, gathering developer feedback, and iterating to improve the integration experience

• Keeping the server secure, versioned, and aligned with our API standards and FCA regulatory obligations

API Quality and Developer Experience

• Auditing and improving our external APIs - naming, consistency, error handling, and documentation

• Building SDKs, code samples, and integration guides that developers actually want to use

• Writing technical content: quickstarts, tutorials, API reference, and how-to guides

• Instrumenting developer journeys to identify where integrations break down and fixing the root cause

Developer Feedback Loop

• Being the voice of the external developer inside Equals Money's engineering teams

• Triaging integration pain points and driving improvements directly - not just creating tickets

• Collaborating with product and engineering to influence API design decisions before they ship

• Engaging with external developers to gather feedback and build trust in the platform

What We’re Looking For

You’ll thrive in this role if you

• Are an engineer first - you write production code and take ownership of what you ship

• Have built or integrated with REST APIs and understand what makes them a joy (or a nightmare) to work with

• Have strong opinions about developer experience and can back them up with working software

• Are comfortable working independently and driving outcomes without a detailed roadmap

• Enjoy being externally facing - writing for developers, gathering feedback, and improving things iteratively

• Can translate between technical complexity and clear, developer-friendly communication

Technical background we’re looking for

• Strong hands-on experience with backend development and API design (REST, webhooks, auth patterns)

• Experience building or owning developer-facing tooling: SDKs, sandbox environments, integration test suites

• Familiarity with MCP (Model Context Protocol) or AI agent integration patterns is a strong plus

• Familiarity with fintech or payments infrastructure is a plus, not a prerequisite

• Comfortable working across the stack where needed - this role touches infrastructure, backend, and docs

Why Equals Money

We’re a profitable, growing fintech building payments infrastructure for businesses. This role is genuinely greenfield - you’ll have real influence over how external developers experience our platform for years to come.

• High ownership from day one

• Direct access to engineering leadership and product decisions

• Competitive salary, hybrid working, and a team that values outcomes over process

• The chance to build something that meaningfully improves how developers work

Our investment in you: We welcome people into the Equals group and desire to grow and develop our talented teams. We believe in teamwork and celebrating our successes. We strive to embrace our values. We want to put you in the driving seat of your career and achieve your full potential through growth opportunities and developmental support.

When you join the Equals Group, we aim to help you to get more out of your career. We will also offer you the following benefits;

Benefits

• A competitive salary benchmarked against a peer group.

• 25 days holiday per year

• Free onsite Nuffield Health gym & pool (London) and discounted gym membership elsewhere

• GetActive with Aviva - Health and Wellbeing discounts on services and products

• Interbank currency rates on travel money and international transfers.

• AXA Private Healthcare

• Free Eye Test and £50 up to the cost of glasses

• EAP Service - Mental Health Services

• Life Assurance Policy - x3 annual salary

• Contributory pension scheme

• Cycle to Work Scheme

• Season Ticket Loans

• Enhanced Parental Policies

• Complimentary tea, coffee, soft drinks and fruit

• We operate a hybrid working arrangement where possible

Working Arrangements

Where possible, we offer the opportunity to work flexibly and the opportunity to balance some remote working with time in the office collaborating, taking part in events and developing the social connections that make working with us rewarding.

Equals Group strives to create a workplace where we can all be ourselves. We believe in inclusion, equality and the power of diversity, so you'll be encouraged to bring your unique perspectives and experiences, and help us understand what you need to do your best work.