Senior Backend Developer

The Protein Works is a UK direct-to-consumer sports nutrition brand. We develop and manufacture our own products, sell them through our own e-commerce platform and ship them from our own warehouse. Behind the website sits a set of internal applications connecting orders, stock, finance, fulfilment and manufacturing, alongside a growing number of marketplaces and third-party services.

We are replacing those legacy internal applications with a new cloud-native platform: independently deployable services that will become the single integration layer between the website, finance, warehouse and manufacturing, and a foundation for AI-assisted automation across the business. This role is a core builder of that platform.

You will join a small, polyglot engineering team working DevOps, Information Security, Data and IT. Go is our preferred language for services because of its performance and operational simplicity, but we hire for engineering depth first: if your background is C#, Java or PHP and you are willing to work in Go, we want to hear from you.

What you will do

Platform Development & Architecture: Design, build, and maintain microservices and domain models (orders, stock, fulfilment, finance) using Go, Domain-Driven Design, enterprise integration patterns, and clean architecture to incrementally replace legacy applications.

Integration & Asynchronous Workflows: Build event-driven and queue-based workflows with REST APIs, authentication, idempotency, and contract testing to connect e-commerce, ERP, WMS, finance, and manufacturing systems.

Operations, Security & AI: Own end-to-end delivery including containers, CI/CD, IaC, full observability (metrics, traces, logs), security/privacy compliance (OWASP, GDPR, pen testing), and day-to-day use of AI-assisted/agentic tools.

Cross-Functional Leadership: Collaborate across tech and business teams, write ADRs, contribute to golden-path templates/standards, and translate business needs into technical execution.

• Backend & Architecture: 5+ years of backend development (Go, Java, C#, or PHP with a focus/openness to Go) with strong CS/software engineering foundations, SOLID principles, and clean/event-driven patterns across microservices and monoliths.
• Data & Async Systems: Solid background in relational databases (PostgreSQL, MySQL, SQL Server) and asynchronous messaging (queues, events, retries, idempotency).
• DevOps & Observability: Practical experience with Docker, Linux/Windows, Git/GitHub, Jira/Agile, monitoring/alerting, and diagnostic/profiling tools in high-volume e-commerce environments.
• Communication & AI Integration: Strong problem-solving and stakeholder communication skills, coupled with active practice using AI development/coding tools.

• AI & Cloud Technologies: Agentic AI (LLMs, frameworks, guardrails) and cloud platforms (AWS, IaC/Terraform, serverless, managed messaging, Kubernetes, Redis, Elasticsearch/OpenSearch).
• Advanced Engineering & Integrations: Production Go experience, GoF/Enterprise integration patterns, durable workflows, contract testing, ERP/WMS/e-commerce integrations, OpenTelemetry/Grafana/Datadog, and OWASP/ISO 27001 security standards.

How we work

Two-week sprints for planned platform work and a Kanban lane for operational and integration requests, both in Jira. Pull requests with code review, automated tests and CI/CD to staging and production. Architecture Decision Records for anything that changes the shape of the platform, and golden-path templates per language so services stay consistent without forcing one runtime. Observability, security and documentation are part of the definition of done.

What we offer

• State of the art PW Campus
• Hybrid working
• A greenfield platform to build, a modern toolchain and direct access to the decisions that shape both
• Company bonus eligibility
• Exclusive staff discounts
• Private healthcare
• Birthday day off
• Pension scheme
• Access to staff discounts
• Staff socials and events
• Refreshments on-site