• Design, build, and maintain scalable backend services, APIs, and data systems • Contribute to frontend application development using modern web technologies • Collaborate cross-functionally with Product, Design, AI, and Engineering teams to ship high-impact product improvements • Improve system reliability, observability, performance, and developer tooling • Help shape technical direction, architecture decisions, and engineering best practices • Investigate and resolve complex production issues across the stack • Prototype quickly, gather feedback, and iterate based on customer and business needs • Mentor developers through collaboration, code reviews, and technical discussions

Title: Senior Full Stack .NET Developer (Web Dev/CS) - REMOTE working Location: UK Department: I Employment Type Permanent - Full Time Job Description: At Mountain Warehouse we understand that technology is core to our success as a business and so we invest heavily in our in-house team. The development department is divided into product-based teams, all using variants on Kanban for project prioritisation and a focus on continuous delivery, mostly with usage of microservices. We are a collaborative team with a strong culture of code review, occasional usage of pair programming and lots of unit tests. We’re keen to write code following best practice and to continuously find ways that we can be even better. The work is a mixture of green-field and legacy projects (much like any other mature organisation) mostly using C#, SQL Server, Next.js, React & TypeScript, with a combination of monolithic and microservices architectures. Key Responsibilities We are looking for technically strong and organised senior developers to join the Web Development team and the team responsible for systems related to Customer Experience and Customer Service. The applications are a mixture of internal services and public-facing applications, based on a range of tech stacks and across cloud, datacentre, and modern edge/serverless environments. We would like to meet someone who is - Minimum 6 years of solid C# in a commercial environment - Minimum 4 years’ commercial experience of React/TypeScript - Produces initial results rapidly and iterate based upon feedback. - Knowledge of microservice design principles - preferably with commercial experience. - Experience with modern git workflows. - Effective communicator and excellent communication skills. - Makes pragmatic implementation decisions and can fail fast if an approach is not working. - Understands projects and project goals in depth. - Experience or willingness of mentoring junior members of a team. - A strong desire to create high-quality, tested code. A selection of what we’re using across the department, let us know what you have experience of; we can train in the rest. - Microservices architecture. - Docker, Kubernetes in Azure, Vercel. - Jenkins / BitBucket Pipelines for CI/CD. - RabbitMQ / MassTransit. - Microfrontends. - Test Driven Development. - RESTful API design. - GraphQL APIs. - Integrations with third-party APIs and SaaS platforms. Benefits - Competitive salary and benefits package - REMOTE working - Holiday allowance - 50% staff discount & 25% for family and friends - Pension scheme

• Design and build scalable backend systems for a high-performance SaaS product • Architect and implement RESTful APIs to support web and product features • Translate product requirements into efficient system and database designs • Optimize system performance for speed, scalability, and reliability • Design data flow across services involving search, caching, and asynchronous processing • Build and maintain secure and reliable cloud-based infrastructure on AWS • Implement and manage containerized services for deployment and scaling • Ensure system observability through logging, monitoring, and error tracking • Collaborate with product and engineering teams to define technical solutions • Participate in architecture decisions for scaling multi-tenant SaaS systems • Identify bottlenecks in existing systems and implement performance improvements • Ensure code quality through reviews, testing practices, and engineering standards

• Set technical direction for your area - make build-vs-buy decisions, define architecture, and own the technical roadmap alongside product leadership. • Take ambiguous problems and make them concrete - scope work, identify risks, break down large initiatives into deliverable increments, and drive alignment across teams. • Design and deliver production-grade systems - scalable pipelines, robust services, and high-performance solutions that serve real users at scale. • Leverage AI tools as part of your workflow - you use AI-assisted development (Claude Code, Cursor, Copilot) to accelerate your work and have formed opinions on when it helps and when it gets in the way. • Evaluate and integrate AI/ML capabilities into production systems when the problem calls for it - you don't need to be an ML researcher, but you're sharp enough to pick up LLMs, embeddings, or classification models and put them to work. • Drive cross-team technical initiatives - influence engineers and teams you don't manage. Lead RFCs, drive architectural reviews, and build consensus on hard technical decisions. • Own what you build - from requirements to release to production. You build it, you run it. You monitor SLOs/SLIs, troubleshoot production issues, and continuously improve reliability. • Raise the engineering bar - through code reviews, mentorship, technical documentation, and by modeling the standards you expect from others.