Software Engineer in Milton Keynes

CreatePay is building its Payment Facilitator (PayFac)/Acquiring platform and is looking for a hands-on, experienced Software Engineer to take full ownership across design, build, and delivery. This is not a traditional engineering role — there is no rigid separation between engineering and product. You will work directly alongside the CTO as a technical peer: shaping the core platform architecture, challenging thinking, and making decisive calls.

You will be expected to define problems, shape solutions, and execute independently in a fast-moving payments and fintech environment. From day one you will be a key voice in defining the technical domain, bringing the depth of experience needed to set credible architectural direction and drive outcomes without dependency on external product managers. You will own end-to-end delivery across distributed systems, integrations, data, and infrastructure.

This is an excellent opportunity for a seasoned engineer who has been there before — someone who can walk into an early-stage environment, provide immediate technical credibility, and help the CTO build a platform and team that scales.

Requirements

We value deep, proven engineering experience over academic qualifications. The ideal candidate brings a track record of building and owning complex systems — someone who has seen what good looks like and knows how to get there. They are comfortable operating across multiple domains — backend, data, integration, and infrastructure — and have the product instinct to define scope and prioritise work independently. Payments or fintech exposure is required; what matters is your ability to design and build reliable, scalable systems and to move fast without sacrificing quality.

A generalist mindset — able to deliver in key areas, learn others, outsource/work with 3rd Parties to deliver more. We don't need someone expert in every domain — but the awareness to know how to solve and work with others to bring the full solution to life.

This role is a first hire in a dedicated engineering function — a chance to bring to fruition the output of experience, help create and shape a modern technology operation. We'll use 3rd party teams to do a lot of build, including architecture and infrastructure/DevOps; this role will be key to building the in-house knowledge and interface to those teams.

Core Responsibilities

• Design and build distributed systems on AWS using serverless-first principles
• Liaise with 3rd Party Engineering teams on all aspects of the engineering lifecycle
• Architect for high availability, fault tolerance, and resilience by default
• Validate 3rd Party deliverables, workshop solutions, troubleshoot issues
• Design scalable data approaches and reporting structures aligned with business requirements
• Define infrastructure strategies including backup, redundancy, and lifecycle management

End-to-End Delivery

• Own the full delivery lifecycle: requirements definition, architecture, implementation, deployment, and ongoing support when required
• Act as de facto product owner: define scope, prioritise work, and drive outcomes without dependency on external PMs
• Ensure outputs are production-ready, maintainable, and observable from day one
• Apply AI and automation tooling to accelerate development, testing, and operations

Integrations & API Development

• Both independently and via 3rd Party Engineering team
• Integrate third-party services, for example payment processors, KYC/KYB providers, fraud platforms, and banking APIs
• Build and maintain robust API layers including validation, orchestration, and workflow logic
• Implement secure, PCI-aware designs aligned with payments industry expectations

Data & Infrastructure

• Design and maintain data pipelines and reporting structures using AWS native tooling
• Apply high availability and fault tolerance patterns across all infrastructure
• Ensure codebases and infrastructure are maintainable and transferable across engineers

Technology Environment

• AWS (primary platform)
• AWS Data Tooling — with backup, redundancy, and lifecycle strategies
• Infrastructure patterns: high availability, fault tolerance, and resilience by default

Key Requirements

• Depth of experience: A substantial engineering background — you have designed and delivered complex systems end-to-end, are confident advising and challenging technical direction alongside leadership
• Payments domain knowledge: Exposure to one or multiple parts of the card payments process, from PSPs to Aggregators, Acquirers to Schemes to Issuers. Know one end of an ISO8583 message from the other
• Independent, multi-domain engineering: Proven ability to operate across backend, data, integration, and infrastructure with minimal oversight and high accountability
• API design and external integrations: Strong experience designing and building APIs and integrating third-party services at scale
• Event-driven and serverless architectures: Hands‑on experience building on AWS using serverless patterns and event‑driven design
• Data modelling and relational databases: Solid understanding of data modelling and PostgreSQL; ability to design schemas for long‑term extensibility
• Security and reliability by design: Ability to design for scale, security, and reliability from first principles, including PCI‑aware environments
• AI and automation tooling: Demonstrated use of AI and automation tools to increase delivery speed and output quality

The following experience is advantageous but not essential:

• Familiarity with PayFac, ISO, or payment gateway architecture

Operating Model

• Works directly alongside the CTO — a trusted technical partner, not a managed resource
• Minimal oversight; high accountability
• Engineering-led product definition
• Bias toward execution and delivery over process
• Systems that are secure, scalable, observable, and cost-efficient
• Codebases that are maintainable and transferable across engineers
• Infrastructure and data models designed for long‑term extensibility
• Measurable impact on delivery speed through automation and tooling

Equity / options — a stake in the business. Significant scope to grow the role and take on broader platform/infrastructure leadership as CreatePay scales. Hybrid working (likely 1 day a week in the office in Milton Keynes).

Please note, this position is only suitable for candidates who currently live in and are eligible to work in the UK. CreatePay is an equal opportunities employer, and we welcome applications from candidates with non-traditional career paths where the experience is demonstrably there.