Senior Software Developer
*\*Strictly no recruitment agencies*
Full time Senior Software Developer wanted.
Calling All Senior Software Developers!
Ready to make a real impact?
We're on the lookout for a Senior Software Developer to join our dynamic team.
If you're passionate about coding and eager to tackle exciting challenges, this is the opportunity for you. As a Senior Software Developer, you'll lead the charge on our most innovative product development, collaborating with a talented team to bring game\-changing ideas to life.
Forget the corporate jargon – we're all about getting things done and making a difference. If you're ready to roll up your sleeves, we want to hear from you. Let's build the future together.
TellJO is a for\-profit, mission\-driven company proactively supporting people susceptible to vulnerability. TellJO puts purpose before profit and believes in a fair and equal society for all.
Working for a startup is not easy. TellJO is seeking an individual who wants to have a tangible impact on our business and has the courage and determination to drive the product development forward at pace.
Role and Responsibilities
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
Essential Skills \& ExperienceSecurity \& 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
Microsoft Azure
· 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
Desirable Skills
· ASP.NET Core MVC
· Microsoft Entra ID / Azure AD
· ISO 27001 or Cyber Essentials
· WordPress
· SaaS platform experience
· 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
- Purpose\-Driven Work – Help vulnerable people avoid crisis and regain control
- Innovative Tech – Work on meaningful, modern software that makes a difference
- Growth \& Learning – Be part of a team that supports continuous development
Office Based \- Worthing (Brooklands House \- Lancing)
37 Hours per week Monday to Friday 28 days holiday including bank holidays (per annum) (pro rata)
Job Type: Full Time
Salary: £45,000 to £57,000 per annum
Other: The job is office based in Worthing, so ability to commute daily is essential
For an informal chat reach out to dominic.maxwell@telljo.org 07901 555230
Job Type: Full\-time
Pay: £45,000\.00\-£55,000\.00 per year
Work Location: In person
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