Senior Python Developer

ARCS; Gauteng; On-site; ZAR 900,000 - 1,200,000; Full time

Job summary

ARCS is seeking an experienced Python developer to lead the evolution of our platform services in a fintech context. You will translate complex business requirements into robust domain models, apply DDD, and ensure clean boundaries between services. Strong cloud, CI/CD, and mentoring skills are essential.

The role focuses on production-ready systems, scalable architectures, and safe migrations in a regulated financial environment, with a bias toward resilient backend design.

Qualifications

• 5+ years of hands-on Python development experience.
• Fintech industry experience is essential.
• Experience with Django is preferred.
• Experience with cloud and containerised environments.
• Practical exposure to AWS, Kubernetes and/or OpenShift/K3s.
• Experience working with live production systems and safely implementing migrations, backward-compatible changes and phased rollouts.
• Experience within regulated environments, particularly banking or financial services, is strongly preferred.

Responsibilities

• Lead the development and evolution of Python/Django platform services from requirements through production deployment.
• Translate business requirements into clear domain models with defined boundaries.
• Apply Domain-Driven Design principles and bounded contexts to production systems.
• Assess impact of architectural decisions across operations, reporting and integrations.
• Design systems to minimize duplication and unnecessary coupling.
• Evolve production systems with backward-compatible changes and phased rollouts.
• Champion CI/CD pipelines, automated testing and cloud-native practices.
• Mentor junior and mid-level developers through reviews and guidance.
• Take ownership of technical delivery and identify risks in architecture and implementation.

Skills

Python

DDD

Cloud & containers

AWS

CI/CD

Mentoring

Education

CS/Software Eng degree or equivalent

Tools

Django

AWS

Kubernetes

OpenShift/K3s

Job description

Duties & Responsibilities

• Lead the development and ongoing evolution of Python/Django platform services, from requirements and architecture through to production deployment.
• Translate complex and evolving business requirements into clear domain models with well-defined boundaries and ownership.
• Apply Domain-Driven Design (DDD) principles and bounded contexts to production systems.
• Assess the broader impact of technical decisions across operations, reporting, integrations, downstream capabilities and system configurations.
• Establish appropriate separation between business rules, application boundaries and reusable platform capabilities.
• Design systems that minimise duplicated logic, unnecessary coupling and architectural divergence.
• Make pragmatic architectural decisions, introducing structure where it provides genuine value while avoiding unnecessary abstraction.
• Evolve production systems through backward-compatible changes, safe migrations and incremental/phased rollouts.
• Apply appropriate migration strategies, including expand-and-contract patterns where required.
• Design systems for correctness and resilience under retries, failures and recovery scenarios.
• Build auditability, data lineage, observability and appropriate failure handling into production systems.
• Design, build and maintain backend systems within cloud and containerised environments.
• Work with technologies and platforms including AWS, Kubernetes and OpenShift/K3s.
• Contribute to technical direction across codebases, APIs and data models.
• Evaluate where capabilities should reside within core platform functionality versus client-specific implementations.
• Review technical designs and ensure they align with agreed engineering standards.
• Mentor junior and mid-level developers through code reviews, technical guidance and knowledge sharing.
• Take ownership of technical delivery and proactively identify architectural, implementation and operational risks.
• Champion reusable CI/CD pipelines, automated testing, effective release practices and cloud-native engineering standards.
• Support secure packaging and deployment of application artefacts, including offline and on-premises deployment mechanisms where required.
• Participate in rotational production support and lead incident response when necessary.
• Promote high standards of reliability, security and confidentiality when developing and supporting production financial systems.
• Use AI-assisted development tools responsibly to improve delivery speed while maintaining code quality, security and appropriate review standards.

Essential Experience

• 5+ years of hands-on Python development experience.
• Previous experience within the Fintech industry is essential.
• Strong experience building production applications using Python frameworks and libraries.
• Experience with Django is preferred.
• Experience working with well-structured domain models and clearly defined service boundaries.
• Strong understanding of separation of business concerns within production systems.
• Experience developing applications for cloud and containerised environments.
• Practical exposure to AWS, Kubernetes and/or OpenShift/K3s.
• Experience working with live production systems and safely implementing migrations, backward-compatible changes and phased rollouts.
• Experience within regulated environments, particularly banking or financial services, is strongly preferred.

Technical & Professional Skills

• Strong technical judgement and the ability to evaluate architectural trade-offs.
• Ability to understand and contribute to wider architectural and structural decisions.
• Strong systems-thinking capability and an understanding of the downstream impact of technical decisions.
• Ability to work effectively with ambiguity and constructively challenge requirements or technical designs when appropriate.
• Strong problem-solving and analytical skills.
• Strong understanding of production reliability, security and confidentiality.
• Ability to collaborate effectively within a technical team and contribute to a shared engineering vision.
• Strong mentoring mindset with the ability to support and develop junior and mid-level developers.
• Ability to take ownership of technical delivery and proactively identify risks.
• Comfortable working within CI/CD, automated testing and modern cloud-native engineering practices.
• Responsible and effective use of AI-assisted development tools while maintaining engineering quality and security standards.

Education

• Degree in Computer Science, Software Engineering or a related field; or equivalent practical experience.