Python Developer

Junior Full Stack Developer (python, React) - Jhb - Onsite

ENVIRONMENT:Our client is a specialist cybersecurity organisation providing advanced cybersecurity and digital forensic services to government and commercial clients. They are seeking a Python Developer to maintain, enhance and further develop in-house products and client-facing services. The role involves taking ownership of an existing web application built around a Flask-based HTML interface and a Python/FastAPI backend.The successful candidate will be responsible for developing new features, maintaining application functionality, resolving technical issues, improving security and supporting deployments. Working closely with the CTO and cybersecurity specialists, the candidate will translate business and operational requirements into reliable, secure and maintainable software solutions. This role is suited to a hands-on developer who is comfortable working with an existing codebase, improving production systems incrementally and taking accountability for the quality, security and reliability of the software delivered.DUTIES: Take ownership of the existing application codebase, understand its architecture and identify opportunities to improve reliability, security and maintainability. Develop, maintain and enhance Python applications and components using Flask and FastAPI. Maintain and improve web interfaces, templates, forms and interactive features using HTML, CSS and JavaScript. Design, develop and maintain REST APIs and integrations with internal systems and external services. Implement and maintain authentication, role-based access controls and appropriate separation of customer data. Investigate and resolve application defects, performance issues and production incidents. Improve code structure and address technical debt through practical, incremental enhancements. Develop and maintain automated tests for critical application functionality and workflows. Manage application dependencies, configuration and the secure handling of credentials and secrets. Support application deployments, logging, monitoring and operational troubleshooting. Maintain technical documentation covering application architecture, configuration, deployment procedures and key functionality. Collaborate with the CTO and cybersecurity specialists to develop features aligned with operational requirements and client needs. Apply secure development practices to protect application functionality, customer data and system integrity. Review, test and maintain code, including code developed with AI-assisted development tools where applicable. Demonstrable experience developing and supporting production Python web applications. Strong working knowledge of Flask and FastAPI. Proficiency in HTML, CSS, JavaScript and server-rendered templates. Experience designing, integrating and troubleshooting REST APIs. Experience working with databases and writing efficient data-access code. Understanding of secure web development principles, including authentication, authorisation, session management, input validation and common web vulnerabilities. Experience using Git and structured code review practices. Practical experience with Linux, Docker and application deployment. Ability to understand unfamiliar codebases and implement changes without disrupting existing functionality. Strong debugging and troubleshooting skills. Ability to work independently while communicating progress, technical decisions and risks clearly. A relevant qualification in Software Development, Computer Science or a related field would be advantageous; equivalent practical experience and a proven track record of maintaining production applications will also be considered. Experience with cybersecurity, threat intelligence or digital risk monitoring platforms. Experience developing multi-tenant applications and subscription-based software products. Familiarity with Elasticsearch, background task processing, queues and large datasets. Experience with automated deployment pipelines and application monitoring. Experience improving the performance, stability and reliability of existing production platforms. Familiarity with AI-assisted development tools, with the ability to independently understand, review, test and maintain generated code. Strong ownership: Takes accountability for application quality, reliability, security and ongoing maintenance. Analytical and problem-solving: Able to investigate complex technical issues, identify root causes and implement effective solutions. Security-conscious: Understands the importance of secure coding practices, data protection and application access controls. Quality-driven: Produces clean, maintainable and well-tested code while minimising disruption to existing functionality. Practical and pragmatic: Makes sound engineering decisions and improves systems incrementally without introducing unnecessary complexity. Adaptable and resourceful: Comfortable navigating unfamiliar codebases, learning existing architectures and working through technical challenges. Self-motivated: Able to work independently, prioritise tasks and take initiative when identifying improvements. Collaborative: Works effectively with the CTO and cybersecurity specialists to understand requirements and deliver practical solutions. Clear communicator: Communicates progress, technical issues, risks and proposed solutions effectively. Detail-oriented: Maintains high standards of accuracy, documentation, testing and security. Accountable and dependable: Follows through on commitments and takes responsibility for the software delivered. Continuous learner: Keeps up to date with relevant development practices, security improvements and emerging technologies. Desired Skills: Junior Full Stack