Full Stack Developer .NET & React

Source Group International; Greater London; Hybrid; GBP 68,000 - 108,000; Full time

Job summary

Source Group International in London is seeking a Full Stack Developer to join our Financial Services analytics team. You will design, build, and evolve analytics applications using C#/.NET on the backend and React on the frontend, delivering end-to-end solutions.

You will collaborate with traders, operators, and analysts to translate quantitative requirements into robust software, participate in design discussions, and ensure high-quality, scalable code across the full development lifecycle.

Qualifications

• Bachelor's or master's degree in Mathematics, Applied Mathematics, Engineering, Physics, a similar quantitative discipline, Computer Science, or a closely related field.
• Up to 10 years of professional software development experience, typically 4–9 years.
• Strong commercial experience with C# and .NET, including ASP.NET Core and Web APIs.
• Strong experience with React and modern frontend development.
• Solid understanding of data structures, algorithms, and computational problem-solving.
• Experience working with relational databases and SQL (SQL Server, PostgreSQL, Oracle).
• Comfort reasoning about numerical data, models, edge cases, and correctness.
• Experience working in agile or scrum environments.
• Strong communication skills and ability to engage with both technical and non-technical stakeholders.

Responsibilities

• Design, build, and enhance end-to-end analytics applications using C#/.NET on the backend and React on the frontend.
• Work across the full development lifecycle from concept and modelling through to implementation, testing, and deployment.
• Collaborate with traders, operators, and analysts to translate quantitative requirements into robust software solutions.
• Build performant, maintainable APIs and services that support data-heavy and computation-focused use cases.
• Develop intuitive, data-driven user interfaces that present complex logic and datasets clearly; participate in design discussions and code reviews.
• Deliver high-quality, well-tested code under time pressure with a focus on correctness and performance.

Skills

C#

NET

ASP.NET Core

Web APIs

React

Frontend development

SQL

Relational databases

Agile/Scrum

Communication

Education

Bachelor's degree in a quantitative field

Master's degree in a quantitative field

Computer Science degree

Tools

GraphQL

Oracle

PostgreSQL

Kafka

gRPC

React

Job description

Salary: £68,000 - 108,000 per year

Requirements:

• Bachelors or Masters degree in Mathematics, Applied Mathematics, Engineering, Physics, a similarly quantitative discipline, Computer Science, or a closely related field
• Up to 10 years of professional software development experience, typically 4–9 years
• Strong commercial experience with C# and .NET, including ASP.NET Core and Web APIs
• Strong experience with React and modern frontend development
• Solid understanding of data structures, algorithms, and computational problem-solving
• Experience working with relational databases and SQL, such as SQL Server, PostgreSQL, or Oracle
• Comfort reasoning about numerical data, models, edge cases, and correctness
• Experience working in agile or scrum environments
• Strong communication skills and the ability to engage directly with technically minded and non-technical stakeholders

Responsibilities:

• Design, build, and enhance end-to-end analytics applications using C#/.NET on the backend and React on the frontend
• Work across the full development lifecycle, from concept and modelling through to implementation, testing, and deployment
• Collaborate directly with business users such as traders, operators, and analysts to translate quantitative requirements and workflows into robust software solutions
• Build performant, maintainable APIs and services that support data-heavy and computation-focused use cases
• Develop intuitive, data-driven user interfaces that present complex logic and datasets in a clear, usable wayContribute to design discussions, code reviews, and architectural decisions within a highly skilled global team
• Deliver high-quality, well-tested code under time pressure while maintaining a strong focus on correctness and performance

Technologies:

• ASP.NET
• Backend
• C#
• Frontend
• GraphQL
• Support
• Oracle
• PostgreSQL
• React
• SQL
• Web
• gRPC
• Kafka
• Quant
• UX UI Design
• Fullstack

More:

We are hiring a Full Stack Developer for our Financial Services team in London on a hybrid basis. You will join a highly collaborative analytics team building and evolving a global analytics platform at the intersection of software engineering, data, and applied mathematics. We work closely with traders, analysts, and operations teams to turn large, complex datasets into actionable insights. This is a hands-on engineering role with a balanced 50/50 split between backend and frontend development, and we value a quantitative mindset, strong problem-solving skills, and a pragmatic, delivery-focused approach. Desirable experience includes quantitative, trading, commodities, or financial systems, messaging or event-driven architectures, Reactive Extensions, async workflows, concurrency-heavy systems, GraphQL, gRPC, and analytics, optimisation, or decision-support systems.

last updated 36 week of 2026