Senior GemStone Developer

Johannesburg, South Africa | Posted on 24/08/2026

Are you a Senior Developer who enjoys solving complex technical challenges, working with unique technology, and making enterprise systems faster, smarter and more resilient?

We’re looking for a Senior Gem Stone Developer to join our team and take ownership of the design, development, optimisation and maintenance of complex Gem Stone/S Smalltalk applications.

This is more than a coding role. You’ll be a technical problem-solver, systems thinker and Gem Stone Subject Matter Expert , helping shape technical solutions, improve platform performance, mentor developers and contribute to the evolution of critical enterprise applications.

• Design, develop, test and maintain applications using the Gem Stone/S Smalltalk platform .
• Translate business and functional requirements into robust, scalable technical solutions.
• Write clean, efficient, maintainable and well-documented code.
• Conduct code reviews and provide constructive technical guidance.
• Troubleshoot and resolve complex production issues.
• Optimise application performance, reliability and scalability.
• Leverage AI-assisted development and testing tools to improve productivity, quality and resilience.

• Contribute to technical and architectural decisions across new and existing platforms.
• Participate in technical design sessions, solution walkthroughs and architecture discussions.
• Ensure solutions align with enterprise architecture, security and development standards.
• Identify opportunities to introduce AI-driven automation, predictive capabilities and intelligent monitoring .
• Help evolve platforms to support future business and technology requirements.

• Follow coding standards, development methodologies and version-control practices.
• Identify technical risks and recommend practical mitigation strategies.
• Support testing, deployment and release activities.
• Help ensure stable, secure and reliable production environments.
• Use modern tooling, including AI-driven capabilities, to strengthen code quality, anomaly detection and system monitoring .
• Work closely with Business Analysts, QA/Testers, Dev Ops, Infrastructure and other technology teams .
• Contribute to technical scoping, estimation and delivery planning.
• Translate complex technical concepts into clear business language.
• Build strong relationships with technical and non-technical stakeholders.
• Mentor and support Junior and Intermediate Developers .
• Act as the team's Gem Stone Subject Matter Expert .
• Share knowledge, best practices and technical expertise.
• Contribute to documentation, knowledge-sharing and continuous improvement.
• Encourage the responsible adoption of AI tools and modern development practices .

• Bachelor’s Degree in Computer Science, Information Technology, Engineering or a related field — or equivalent practical experience.
• 7+ years’ software development experience .
• 4+ years’ hands-on experience with Gem Stone/S Smalltalk or similar persistent object-oriented environments.
• Proven experience working with enterprise-scale production systems .
• Advanced knowledge of object-oriented design and design patterns .
• Strong understanding of database design, persistent object stores and performance tuning .
• Excellent debugging, profiling and system optimisation capabilities.
• Experience with version-control technologies such as Git, SVN or equivalent .
• Understanding of CI/CD pipelines and modern deployment practices .

• Experience with in financial services, insurance, investments or other high-transaction environments .
• Exposure to AI-assisted software development tools .
• Experience integrating or working with machine learning / AI technologies .
• Experience with large-scale, highly available and business-critical applications.