.NET Back-End Developer

Ocean Technologies Group; United Kingdom; Remote; GBP 40,000 - 66,000; Full time

Job summary

Ocean Technologies Group is seeking a Mid-level .NET Back-End Developer for UK Remote work. You will design, build, and maintain robust server-side applications and APIs powering our products.

Collaborate with product managers, frontend teams, and QA in an Agile setting to deliver end-to-end features with clean architecture and strong security. You will work with .NET 8+, C#, EF Core, SQL Server, and modern tooling (Azure DevOps, Docker, Kubernetes).

Qualifications

• Multiple years of commercial experience in back-end development.
• At least 5 years with .NET C#.
• Experience with .NET 6+/NET 8+, EF Core, LINQ, SQL Server and async programming.
• Experience implementing JWT, OAuth2, and OpenID Connect (Azure Entra or Duende IdentityServer).
• Azure DevOps for Boards and CI/CD; Docker for containerisation.
• Unit and integration testing with xUnit; FluentValidation for data integrity.
• Structured logging with Serilog and monitoring via Application Insights.

Responsibilities

• Build, iterate, and maintain back-end services, RESTful/GraphQL APIs, and microservices using .NET.
• Collaborate with product managers to translate complex requirements into clean, performant code.
• Work in an Agile/Sprint framework with front-end, QA, and product teams.
• Ensure code quality through Clean Architecture, testing, and refactoring.
• Identify and resolve performance bottlenecks and security issues.
• Maintain API documentation (Swagger/OpenAPI).

Skills

.NET

C#

Entity Framework Core

Azure DevOps

Docker

Kubernetes

Swagger/OpenAPI

xUnit

FluentValidation

Serilog

Application Insights

OAuth2/OpenID Connect

JWT

Tools

Azure DevOps

Docker

Kubernetes

Swagger/OpenAPI

Job description

Description Discover OneOcean:

Department: Technology

Location: UK Remote

Navigating the position: .NET Back-End Developer

We have a proven concept and a solid foundation, now, we need a Mid-level Back-End Developer with strong .NET expertise to join our engineering team and help design, build, and maintain robust, scalable server-side applications and APIs that power our products and services.

You will work closely with product managers to translate complex requirements into clean, maintainable, and performant code, solving complex business problems, and collaborating in an agile environment.

Key Responsibilities

• Build & Iterate: Design, develop, and maintain high-quality back-end services, RESTful/GraphQL APIs, and microservices using .NET.
• Storage: Work with relational databases (primarily SQL Server) - design schemas, write efficient queries, and optimise performance.
• Data Access: Implement data access layers using Entity Framework Core.
• Auth: Build and integrate authentication & authorisation mechanisms.
• Collaborate: Work within a loose Agile/Sprint framework, contributing to storyboarding and regular sprint planning meetings, and work closely with front-end developers, QA engineers, and product owners to deliver end-to-end features.
• Code Quality: Implement clean, maintainable, and automated code testing following Clean Architecture principles and current best practices.
• Performance: Identity and resolve performance bottlenecks, security issues, and production incidents.
• Documentation: Help maintain technical documentation for APIs and services (Swagger / OpenAPI).

Skills, Knowledge and Expertise

You are a mid-level developer who is "hands-on" by nature, you don't want to sit in architectural meetings all day; you want to build great products.

• .NET Specialist: You have a proven track record of building production-grade APIs and services, with deep knowledge of .NET 8+, C#, and Entity Framework Core.
• Data & Security Focused: You are comfortable designing robust database schemas and implementing secure authentication flows (such as OAuth2 or OpenID Connect) to protect user data.
• Tooling Savvy: You are a confident user of Azure DevOps, including managing work items on Boards and understanding how to support CI/CD pipelines and releases.
• Quality Driven: You take pride in writing clean, testable code. You understand Clean Architecture principles and can identify and resolve performance bottlenecks before they hit production.
• Agile Mindset: You're comfortable with the iterative nature of a growing product and can thrive in a sprint-based environment.

Must-Have Technical Stack

• Experience: Multiple years of commercial experience in back-end development; at least 5 years with .NET C#.
• Core: At least 2-3 years with.NET 6+ / .NET 8+, Entity Framework Core, LINQ, SQL Server, and asynchronous programming.
• Data & Persistence: You are proficient with Entity Framework Core (code-first approach) and have experience managing relational databases (primarily SQL Server) including schema design and query optimisation.
• Architecture & Patterns: You have a firm grasp of Clean Architecture and Domain-Driven Design (DDD). You advocate for decoupled systems using Dependency Injection and modular monolith or microservices patterns.
• Identity & Security: You have hands-on experience implementing JWT, OAuth2, and OpenID Connect, specifically using Azure Entra or Duende IdentityServer to build secure, identity-aware applications.
• DevOps & Tooling: Azure DevOps for task management (Boards) and maintaining CI/CD Pipelines. You understand how to use Docker for containerising services.
• Testing & Quality: You prioritise code reliability by writing unit and integration tests using xUnit, and you utilise FluentValidation to ensure data integrity across your APIs.
• Performance & Monitoring: You know how to profile applications and implement structured logging using Serilog, integrated with Application Insights for real-time monitoring.

Valued Technical Stack

• Complexity: Previous work on high-traffic / consumer-facing apps or apps with complex business logic.
• Cloud: Experience with cloud platforms (Azure preferred - App Services, Functions, Key Vault, Service Bus, Cosmos DB, etc.).
• Platform: Knowledge of orchestration (Kubernetes).
• Messaging: Experience with message brokers (RabbitMQ, Azure Service Bus, Kafka).
• NoSQL: Familiarity with NoSQL databases (Cosmos DB).
• Front-end: Basic understanding of front-end technologies (to better collaborate with UI teams)