Full Stack Engineer (C# / .NET & React)

Lorien; Greater London; On-site; GBP 75,000 - 120,000; Full time

Job summary

Lorien is seeking a hands-on Full Stack Engineer to build a brand-new real-time web portal for institutional bond issuers and sales teams in a greenfield project. You will design, develop and deploy a full-stack web application using ASP.NET Core, C#, React and TypeScript, taking it from concept to production with ownership of the full software lifecycle.

Expect to work closely with cross-functional teams to deliver high-performance, accessible interfaces and robust APIs, while implementing

Qualifications

• Strong experience in C# / .NET and React development.
• Experience delivering end-to-end solutions—from development to production.
• Ability to design, build and deploy full-stack applications and APIs.
• Experience with CI/CD pipelines and build automation.

Responsibilities

• Design and build RESTful APIs using ASP.NET Core (6+).
• Develop clean, scalable C# code and data access with EF Core/Dapper.
• Build modern UIs with React 18+ and TypeScript; integrate with Angular or similar.
• Implement CI/CD pipelines, automate builds, tests and deployments.
• Document APIs (Swagger/OpenAPI) and participate in code reviews.

Skills

C# / .NET

React

TypeScript

CI/CD

Angular

Tools

ASP.NET Core

EF Core

Dapper

MSBuild

npm/yarn

Webpack

Bitbucket

TeamCity

Job description

Full Stack Engineer (C# / .NET & React) – Investment Banking

We are working with a leading global investment bank to hire a hands-on Full Stack Engineer to help build a brand-new, high-impact web application from the ground up.

This is a unique opportunity to take ownership of a greenfield project delivering a real-time web portal for institutional bond issuers and sales teams—providing live market insights and new issuance updates.

The Role

You will play a critical role in designing, developing, and deploying a full-stack web application, taking it from concept through to production.

This role requires someone who can hit the ground running, build the entire development pipeline, and take ownership across the full software lifecycle—not just individual development tasks.

Key Responsibilities

Back-End Development

• Design and build RESTful APIs using ASP.NET Core (6+)
• Develop clean, scalable, and testable C# code
• Manage data access using EF Core, Dapper, or similar

Front-End Development

• Build modern, responsive UIs using React (18+) and TypeScript
• Integrate components into existing web applications (Angular or similar)
• Apply best practices for performance, accessibility (WCAG 2.1 AA), and UX
• Contribute to development of secure, client-facing portals

Build, CI/CD & Deployment

• Design and implement CI/CD pipelines (Bitbucket, TeamCity or similar)
• Create build processes using MSBuild, npm/yarn, Webpack
• Configure automated unit, integration, and UI testing
• Manage deployments across staging and production environments
• Contribute to architectural decisions and code reviews
• Document APIs (Swagger/OpenAPI), deployments, and runbooks
• Mentor junior engineers and promote engineering best practices

What We’re Looking For

• Strong experience in C# / .NET and React development
• Proven track record building external client-facing applications or portals
• Experience delivering end-to-end solutions—from development to production
• Strong knowledge of CI/CD pipelines, build automation, and deployments
• Comfortable working in a greenfield environment with high ownership
• A self-starter mindset with the ability to drive delivery independently