At a Glance
- Tasks: Design and develop impactful software that supports vulnerable people.
- Company: Join TellJO, a tech company making a real difference in people's lives.
- Benefits: Enjoy autonomy, competitive salary, and the chance to influence technology direction.
- Other info: Work in a dynamic environment with opportunities for personal and professional growth.
- Why this job: Be part of a mission-driven team and shape the future of our engineering function.
- Qualifications: Strong experience in C#, .NET, React, and cloud security practices.
The predicted salary is between 60000 - 80000 £ per year.
Location: Lancing, West Sussex (Office-Based Monday-Friday)
Build Technology That Changes Lives
At TellJO, we’re using technology to help vulnerable people access support earlier, improve wellbeing, and avoid crisis. Our SaaS platform helps organisations identify vulnerability, understand risk, and deliver better outcomes for the people they support. We’re looking for a Senior Software Engineer to take ownership of our technology platform and play a key role in its ongoing development, operation, and security. This is a hands‑on role with significant autonomy. You’ll be responsible for software development, cloud infrastructure, deployment pipelines, security, and operational resilience. Initially, you’ll operate as the primary technical resource, with the opportunity to help shape and grow the engineering function as the business evolves.
What You’ll Do
- Design, develop, and maintain applications using C#, .NET, React, and TypeScript
- Own and improve our Azure-hosted SaaS platform
- Manage deployment pipelines and release processes using Azure DevOps
- Ensure the platform remains secure, reliable, scalable, and performant
- Manage Cloudflare WAF, Microsoft Defender for Cloud, and security monitoring
- Apply secure‑by‑design principles throughout the software development lifecycle
- Support ISO 27001 and Cyber Essentials compliance activities
- Troubleshoot issues across application, infrastructure, and security layers
- Contribute to product direction, technical architecture, and continuous improvement
- Use modern AI‑assisted development tools to improve productivity and code quality
Security & Platform
- Strong understanding of OWASP Top 10 and secure software development practices
- Experience with Cloudflare WAF and web application security
- Experience with Microsoft Defender for Cloud (Azure Defender)
- Experience identifying, prioritising, and remediating security vulnerabilities
- Strong understanding of authentication, authorisation, MFA, and least‑privilege access principles
- Experience managing Azure-hosted applications and services
- Experience with Azure App Services, Azure SQL, Key Vault, Blob Storage, and monitoring tools
- Experience with Azure DevOps and CI/CD pipelines
- Understanding of cloud security, resilience, and operational best practices
Software Engineering
- Strong commercial experience with C# and modern .NET
- Strong React and TypeScript experience
- Experience with Entity Framework Core and SQL Server
- Experience building and maintaining REST APIs
- Experience designing scalable and maintainable software solutions
- Strong debugging, troubleshooting, and problem‑solving skills
Working Style
- Comfortable operating independently and taking ownership
- Able to balance strategic thinking with hands‑on delivery
- Strong communication skills and a pragmatic approach to problem solving
- ISO 27001 or Cyber Essentials
- Experience working within regulated or security‑conscious environments
Why Join TellJO?
- Build technology that makes a genuine social impact
- Enjoy significant autonomy and ownership
- Work directly with senior leadership
- Influence technical decisions and platform direction
- Help shape the future engineering function as the company evolves
Senior Software Engineer in Lancing employer: TellJO | B Corp™
At TellJO, we pride ourselves on being an exceptional employer that empowers our team to make a meaningful social impact through technology. Located in Lancing, West Sussex, we offer a collaborative work culture where innovation thrives, and employees enjoy significant autonomy in their roles. With ample opportunities for professional growth and direct engagement with senior leadership, joining us as a Senior Software Engineer means contributing to a purpose-driven mission while advancing your career in a supportive environment.
