Senior Gemstone Developer

Khonology (Pty) Ltd; Johannesburg; On-site; ZAR 900,000 - 1,400,000; Full time

Job summary

Khonology is seeking a Senior Gemstone Developer to lead design, development, and optimisation of complex Gemstone-based applications. You will mentor juniors and contribute to architecture decisions while ensuring stability, performance and scalability.

In addition, you will explore AI-assisted approaches to improve testing, monitoring, and automation, embedding smart tooling within production workflows and collaborating with cross-functional teams across the business.

Qualifications

• Bachelor's degree in Computer Science, Information Technology, Engineering or related field (or equivalent practical experience).
• 7+ years' experience in software development.
• 4+ years' hands-on experience with Gemstone/S Smalltalk or similar object-oriented persistent environments.
• Proven experience with enterprise-scale systems in production environments.
• Advanced understanding of OO design and design patterns.
• Experience with database design, persistent object stores and performance tuning.
• Strong debugging, profiling and system optimisation skills.
• Experience with version control systems (Git, SVN, etc.).
• Understanding of CI/CD pipelines and modern deployment practices.
• Experience in financial services, insurance, investments or high-transaction environments (advantageous).
• Exposure to AI-assisted development tools or ML integration (advantageous).

Responsibilities

• Design, develop, test and maintain Gemstone/S applications.
• Translate business requirements into technical solutions.
• Write clean, well-documented code following best practices.
• Provide technical feedback through code reviews.
• Optimize system performance, reliability and scalability.
• Resolve complex production issues with robust fixes.
• Incorporate AI-assisted tools for testing, monitoring and optimisation.

Skills

Strong analytical

Problem solving

Accuracy & quality

Independent worker

Teamwork & communication

People development

Adaptable under pressure

AI tools awareness

Education

Bachelor's degree in CS/IT/Engineering

Tools

Gemstone/S Smalltalk

Git

SVN

CI/CD

Job description

Khonology is a digital services and technology engineering company. Our teams build modern, scalable, and resilient solutions that enable our clients to operate, innovate, and grow.

The Senior Gemstone Developer is responsible for the design, development, optimisation and maintenance of complex Gemstone-based applications within the organisation. The role plays a key part in providing technical leadership, ensuring system stability, performance, and scalability, while mentoring junior developers and contributing to architectural and strategic technology decisions.

The Senior Gemstone Developer is responsible for the design, development, optimisation and maintenance of complex Gemstone-based applications within the organisation. The role plays a key part in providing technical leadership, ensuring system stability, performance, and scalability, while mentoring junior developers and contributing to architectural and strategic technology decisions.

In addition, the role supports the integration of AI-driven approaches where appropriate, enabling smarter automation, enhanced performance monitoring, and data-informed decision-making.

Key Responsibilities:

Technical Development & Delivery

• Design, develop, test and maintain applications built on the Gemstone/S Smalltalk platform.
• Translate business and functional requirements into high-quality technical solutions.
• Write clean, efficient, well-documented and maintainable code aligned with best practices.
• Perform reviews and provide constructive technical feedback to team members.
• Optimise system performance, reliability and scalability of existing applications.
• Resolve complex production issues with robust fixes
• Incorporate AI-assisted tools for testing, monitoring, and optimisation to improve efficiency and resilience.

Architecture & Systems Design

• Contribute to design decisions for new and existing platforms.
• Ensure solutions meet enterprise architecture standards and security principles.
• Participate in technical design sessions and walkthroughs with stakeholders.
• Explore opportunities to embed AI-driven components for smarter automation and predictive capabilities.

Quality, Risk & Governance

• Ensure adherence to coding standards and version control practices.
• Identify technical risks and recommend mitigation strategies.
• Support testing, deployment and release processes for stable production environments.
• Use AI-driven tools to enhance code quality checks and anomaly detection.

Collaboration & Stakeholder Engagement

• Work closely with business analysts, testers, DevOps, and infrastructure teams.
• Provide input to scoping, estimation and delivery planning.
• Convey complex technical concepts clearly to non-technical stakeholders.

Leadership & Mentorship

• Mentor junior and intermediate developers.
• Act as a Gemstone Subject Matter Expert within the team.
• Contribute to knowledge sharing, documentation and continuous improvement initiatives.
• Encourage awareness of AI tools and practices that can enhance productivity and innovation.

Qualifications, Knowledge & Experience

• Bachelor's Degree in Computer Science, Information Technology, Engineering or related field (or equivalent practical experience).
• 7+ years' experience in software development.
• 4+ years' hands-on experience with Gemstone/S Smalltalk or similar object-oriented persistent environments.
• Proven experience working on enterprise-scale systems in a production environment.
• Advanced understanding of object-oriented design and design patterns.
• Experience with database design, persistent object stores and performance tuning.
• Strong debugging, profiling and system optimisation skills.
• Experience with version control systems (Git, SVN, etc.).
• Understanding of CI/CD pipelines and modern deployment practices.
• Experience in financial services, insurance, investments or high-transaction environments (advantageous).
• Exposure to AI-assisted development tools or machine learning integration (advantageous).
• Experience in financial services, insurance, investments or high-transaction environments (advantageous).

Required Skills & Competencies

• Strong analytical and problem-solving skills.
• Excellent accuracy and quality orientation.
• Ability to work independently and take responsibility for complex deliverables.
• Strong teamwork and communication skills.
• Passion for developing others.
• Resilient in high-pressure or changing environments.
• Openness to incorporating AI tools and practices into development workflows.