Senior Software Engineer - Java/C++ (Security Clearance)

Gattaca; Leatherhead; On-site; GBP 65,000 - 95,000; Full time

Benefits offered by this job

25 days holiday

Bonus scheme

Company pension

Life assurance

Cycle to work

Season rail ticket loan

Enhanced parental benefits

Membership fees support

Job summary

Gattaca is seeking an experienced Software Engineer for a permanent role in Leatherhead, working on high-consequence defence software. The successful candidate will hold SC clearance and be willing to undergo DV clearance.

You will design and implement robust Java and C++ components, collaborate with domain scientists, and contribute to software architecture in a consultancy setting. You will work on-site with clients and engineers, mentoring juniors, and supporting business development.

Qualifications

• Professional experience developing software in Java and C++
• Practical experience applying object-oriented design principles and modular software architectures
• Familiarity with collaborative development practices, including Git and CI/CD pipelines
• Experience working across the full software development lifecycle, including design, implementation, testing, and maintenance
• Knowledge of software testing techniques and a commitment to writing reliable, maintainable code
• Solid analytical and problem-solving skills, with the ability to work effectively both independently and as part of a multidisciplinary team
• The confidence and communication skills to work directly with clients and technical stakeholders
• Sole UK nationality, due to the nature of the work
• Experience writing unit tests using JUnit and Google Test Frameworks
• Solid understanding of numerical methods and scientific computing principles
• Background in physics, applied mathematics, or engineering
• Experience in development with Fortran 90
• Experience using the Java Spring framework
• Experience working in the defence sector
• Competitive salary with yearly reviews
• 25 days holiday + the opportunity to buy 5 days
• A company with its heart in the right place and a welcoming work culture
• Happy to talk flexible working
• Enhanced parental benefits
• Company pension scheme
• Life assurance
• Bonus scheme linked to company performance
• Paid membership fees to a professional institution
• Support in attaining professional membership
• Cycle to work scheme
• Season rail ticket loan
• Additional optional benefits tailored to your personal requirements

Responsibilities

• Design, develop, and maintain high-quality software components using Java and C++, with focus on robustness, performance, and maintainability
• Implement and extend code that interacts with a flexible integration framework for solver coupling and data exchange
• Work closely with clients, domain scientists, and computational engineers—often on-site—to understand requirements and translate them into effective software solutions
• Contribute to defining and evolving software architecture, balancing performance, scalability, and long-term maintainability
• Write clean, well-documented, and testable code in line with scientific software development best practices
• Participate regularly in code reviews, debugging sessions, and performance profiling to improve code quality across the team
• Support and mentor junior developers through technical guidance, constructive review, and knowledge sharing
• Over time, take on increasing responsibility for guiding technical direction and contributing to the planning, delivery and management of project work
• Help develop client relationships and contribute to development of new business, such as through writing effective proposals
• Thrive in a consultancy environment solving real-world, high-consequence challenges

Skills

Java

C++

OOD design

CI/CD pipelines

Analytical thinking

Communication

Team collaboration

Education

Physics/Applied Mathematics/Engineering background

Tools

Git

JUnit

Google Test

Spring Framework

Fortran 90

Job description

Gattaca is seeking an experienced Software Engineer for a permanent role in Leatherhead, working on high-consequence defence software. The successful candidate will hold SC clearance and be willing to undergo DV clearance.

You will design and implement robust Java and C++ components, collaborate with domain scientists, and contribute to software architecture in a consultancy setting. You will work on-site with clients and engineers, mentoring juniors, and supporting business development.