Senior Software Engineer

Symmetric Headhunting; Lincoln; On-site; GBP 70,000 - 110,000; Full time

Job summary

Symmetric Headhunting seeks a Senior Software Engineer to own major platform components and drive delivery on a multi-INT data fusion platform. You will stay hands-on in C#/.NET while guiding architectural decisions, mentoring engineers, and maintaining technical quality across your domain.

The role emphasizes secure, scalable software, RESTful APIs, and distributed services, with a focus on architectural alignment and hands-on leadership across teams.

Qualifications

• 3 to 5+ years' professional software development experience.
• Strong C#/.NET and ASP.NET Core expertise.
• Experience building RESTful APIs, distributed systems, or service-based architectures.

Responsibilities

• Own and evolve significant platform components, hands-on in C#/.NET.
• Lead technical direction, design decisions, and cross-team architectural alignment.
• Build and support RESTful APIs and distributed services with ASP.NET Core.
• Design and optimise PostgreSQL relational database solutions for performance and reliability.
• Lead technical investigations, prototypes, and R&D spikes to de-risk delivery.
• Mentor engineers and champion secure development and engineering standards.

Skills

C# / .NET

ASP.NET Core

RESTful APIs

React

Relational databases (PostgreSQL)

Agile delivery

Tools

Git

Docker

SQL (PostgreSQL)

Job description

We're looking for a Senior Software Engineer C#.

This is a hands‑on leadership role: you'll own major platform components, set technical direction, and drive the delivery of secure, scalable software on a multi-INT data fusion platform supporting next‑generation sovereign capability.

You'll stay close to the code while guiding implementation approaches, maintaining architectural consistency, and mentoring engineers across your domain.

Technical Stack

• ASP.NET Core – RESTful APIs & distributed services
• PostgreSQL or equivalent / relational databases

What You’ll Do

• Own and evolve significant platform components, hands‑on in C#/.NET
• Lead technical direction, design decisions, and cross‑team architectural alignment
• Build and support RESTful APIs and distributed services with ASP.NET Core
• Design and optimise PostgreSQL/relational database solutions for performance and reliability
• Lead technical investigations, prototypes, and R&D spikes to de‑risk delivery
• Mentor engineers and champion secure development and engineering standards

What We’re Looking For

3 to 5+ years' professional software development, with strong C#/.NET and ASP.NET Core

• Experience building RESTful APIs, distributed systems, or service‑based architectures
• Modern frontend experience with React or similar
• Strong relational database design and optimisation skills, ideally PostgreSQL
• Sound judgement on scalability, reliability, and secure software design
• Proven ability to take ownership, guide technical delivery, and build trust across teams
• Agile delivery experience and strong communication skills

Bonus Points

Experience in regulated environments; architectural documentation (C4, ADRs); DDD, clean or modular architecture; UX/accessibility awareness.

Why Join?

Take meaningful technical ownership on a strategically important programme, shape platform direction, and work alongside experienced engineers, architects, and DevOps specialists in a team where technical quality and professional development matter.