Senior Full Stack Developer

Harvey Nash Group; Newcastle upon Tyne; On-site; GBP 75,000 - 110,000; Full time

Job summary

Harvey Nash Group is seeking a Senior Full Stack Developer to lead technically complex features across real-time trading platforms. You will own design decisions, mentor engineers and collaborate with Product, QA and Support to deliver robust software across C#/.NET, React and TypeScript stacks.

You will work on secure, resilient systems with focus on performance, observability and long-term maintainability while guiding teams through ambiguous requirements to reliable technical outcomes.

Qualifications

• Deep practical experience designing, building and supporting production software with C# and .NET.
• Full‑stack capability across React, TypeScript, SQL Server and HTTP APIs.
• Experience delivering complex changes through Git, Azure DevOps and CI/CD pipelines.
• Ability to design services, APIs and integrations for distributed, event‑driven and real‑time systems.

Responsibilities

• Design and implement maintainable changes across C#/.NET services, React and TypeScript UIs, HTTP APIs, integrations and SQL Server databases.
• Write and maintain unit, integration, API and front-end tests.
• Use Git, Azure DevOps, build pipelines and CI/CD processes safely and consistently.
• Diagnose application, data and integration issues using logs and monitoring.
• Collaborate with Product, QA and Support to clarify outcomes and acceptance criteria.
• Lead complex changes from discovery through production operation and mentor engineers.

Skills

C#/.NET

TypeScript

React

SQL Server

Entity Framework

HTTP APIs

RabbitMQ

SignalR

Azure DevOps

CI/CD

Tools

Git

Azure DevOps

Build pipelines

CI/CD tooling

Job description

Fantastic opportunity to join a thriving Financial Services business.

What is the role? As a Senior Full Stack Developer, you will lead technically complex features, projects and services where requirements, architecture or implementation approaches are uncertain.

You will turn ambiguous business problems into reliable technical outcomes across the firm's real-time, business-critical trading platforms and guide other engineers contributing to the work. You will provide independent technical leadership within the relevant domain, resolving ambiguity, making significant design decisions and coordinating other contributors while escalating decisions with material product-wide, regulatory, security or architectural consequences. The role combines hands-on work across C#/.NET, React, TypeScript, SQL Server, APIs and integrations with strong attention to security, resilience, performance, operability and long-term maintainability. You will act as a trusted technical adviser to Product and QA, work with Support on significant operational issues, and mentor and guide engineers contributing to complex work. The business offers the opportunity to solve difficult technical challenges across distributed, event-driven and real-time derivatives and structured-products trading systems.

Key Responsibilities

Design and Implementation

• Deliver owned work from clarification and design through implementation, testing, release and production operation.
• Design and implement maintainable changes across C#/.NET services, React and TypeScript user interfaces, HTTP APIs, integrations and SQL Server databases.
• Apply proportionate engineering design and document material decisions, assumptions and trade-offs.

Quality and Testing

• Write and maintain appropriate unit, integration, API and front-end automated tests.
• Use Git, Azure DevOps, build pipelines and CI/CD processes safely and consistently.

Production and Operational Support

• Diagnose application, integration and data issues using logs, monitoring, debugging and data analysis.
• Improve monitoring, alerting, runbooks, documentation and operational readiness.

Collaboration

• Work with Product and Business Analysis to clarify outcomes, priorities and acceptance criteria.
• Work with QA to define suitable coverage and with Support to investigate production issues.
• Participate in design discussion and provide clear, constructive code-review feedback.
• Communicate progress, dependencies, risks and blockers clearly and early.

Technical Improvement

• Identify technical debt, reliability risks and proportionate improvements to tools and practices.
• Use approved AI-assisted engineering tools responsibly and remain accountable for the result.

Coaching and Leadership

• Lead complex changes from discovery and technical analysis through production operation.
• Mentors and guide engineers contributing to complex work.

Required Skill Set

They primarily develop and support real-time trading systems using the technologies below:

• C# and .NET
• TypeScript and React
• SQL Server and Entity Framework
• HTTP APIs and integrations
• RabbitMQ and SignalR
• Azure DevOps and Azure services

Essential

• Deep practical experience designing, building and supporting production software using C# and .NET.
• Strong full-stack capability across React, TypeScript, SQL Server and HTTP APIs.
• Strong knowledge of object-oriented design, relational data modelling and automated unit, integration and front-end testing.
• Experience delivering complex changes through Git-based source control, code review, Azure DevOps and CI/CD pipelines.
• Ability to design services, APIs and integrations and reason about distributed, event-driven and real-time behaviour.
• Strong capability in observability, diagnostics, incident investigation and failure-mode analysis.
• Demonstrated ability to resolve ambiguity, make significant technical decisions and lead complex work without formal authority.
• Understanding of security, performance, resilience, operability, data integrity and long-term maintainability.
• Ability to mentor engineers and coordinate contributors across complex delivery.
• Ability to explain commercial, operational and technical trade-offs to Product, QA, Support and engineering stakeholders.

Desirable

• Experience delivering or operating trading platforms, financial-services systems or other regulated, business-critical software.
• Substantial experience with real-time, high-availability, low-latency or event-driven systems.
• Strong practical experience with RabbitMQ, SignalR, Azure services or Entity Framework.
• Experience with complex front-end workflows, market or reference data, observability and production incident leadership.