SENIOR BACK-END DEVELOPER (Ruby on Rails)
Department: Operations & Delivery
Reports to: Technical Lead
Location: Rosebank, Johannesburg (Hybrid: 3:2 split - 3 days per week onsite; full time onsite for your first 3 months)
WHO PLATFORM45 IS
We are responsible for code changing the lives of people around the world, every day. We solve complex problems and build big ideas. And we don’t stop.
We believe in the ability of technology to make the world a better place; we’re driven to challenge conformity and create smarter solutions and better habits.
We know why we’re here: To unleash the potential of people through the power of technology. We are people multiplied by tech—and together we are changing the world.
CONTEXT | THE ROLE
As a Senior Back-End Developer (Ruby on Rails), you will be responsible for designing, building, and maintaining high-quality, scalable software solutions.
You will work closely with the Technical Lead to implement architectural decisions and ensure engineering excellence across projects. In addition to hands-on development, you will play a key role in mentoring developers, improving code quality, and driving best practices within the team.
This role requires strong technical depth, a proactive mindset, and the ability to take ownership of complex features and systems.
ROLE RESPONSIBILITIES | THE WHAT & THE HOW
Software Development & Delivery
- Design, develop, and maintain robust Ruby on Rails applications.
- Take ownership of complex features and components from design through to deployment.
- Ensure code is clean, maintainable, and aligned with best practices.
Technical Design & Implementation
- Collaborate with the Technical Lead on system design and architecture.
- Contribute to technical decision-making and solution design.
- Ensure solutions are scalable, secure, and maintainable.
Code Quality & Reviews
- Lead by example in writing high-quality code.
- Actively participate in and contribute to code reviews, raising the standard of the team.
- Ensure adherence to coding standards and engineering best practices.
Mentorship & Team Support
- Support and mentor junior and intermediate developers.
- Share knowledge through code reviews, pairing, and technical discussions.
- Contribute to building a strong and collaborative engineering culture.
Troubleshooting & Problem Solving
- Diagnose and resolve complex bugs and production issues.
- Identify root causes and implement long-term solutions.
- Proactively identify performance and scalability improvements.
Collaboration & Stakeholder Engagement
- Work closely with product managers, designers, QA, and other stakeholders.
- Translate requirements into effective technical solutions.
- Communicate technical concepts clearly to both technical and non-technical audiences.
Documentation
- Maintain clear and accurate technical documentation.
- Document architectural decisions, system behaviours, and key implementation details.
Continuous Improvement
- Stay up to date with Rails ecosystem and emerging technologies.
- Contribute to improving development processes, tools, and standards.
Project Contribution
- Contribute to estimation, planning, and technical scoping.
- Manage own workload effectively and support team delivery goals.
TECHNICAL REQUIREMENTS
- Bachelor’s degree in Computer Science, Software Engineering, or related field, or equivalent practical experience.
- 5–8+ years of experience in software development, with strong Ruby on Rails expertise.
- Proven experience building and maintaining production-grade applications.
Core Skills
- Strong proficiency in Ruby on Rails and modern Rails practices.
- Experience with ViewComponent and the Hotwired stack (Turbo, Stimulus, Hotwire).
- Solid experience with relational databases (PostgreSQL, MySQL) and data modelling.
- Experience building RESTful APIs and integrating third-party services.
- Strong Git experience and collaborative workflows.
Infrastructure & Tooling
- Experience with cloud platforms (AWS, GCP, or Azure).
- Familiarity with Docker and containerised environments.
- Experience with CI/CD pipelines (GitHub Actions, Jenkins, CircleCI).
- Understanding of performance optimisation and monitoring.
Methodologies
- Strong understanding of Agile methodologies (Scrum, Kanban).
- Experience working in cross-functional teams.
CRITICAL COMPETENCIES
- Strong sense of ownership and accountability for delivery.
- Analytical thinker with the ability to solve complex technical problems.
- Ability to work independently while collaborating effectively within a team.
- Proactive and solutions-oriented mindset.
- Strong communication and interpersonal skills.
- Passion for continuous learning and improvement.
- Willingness to mentor and support other developers.
- Forward-thinking approach to building scalable and maintainable systems.
Skills Required
- Bachelor's degree in Computer Science or related field
- 5-8+ years of experience in software development
- Strong proficiency in Ruby on Rails
- Experience with PostgreSQL and MySQL
- Experience in building RESTful APIs
- Experience with cloud platforms (AWS, GCP, Azure)
- Experience with CI/CD pipelines
What We Do
At Platform45 we promote ideation, we collaborate, we “iterate-iterate-iterate”, and above all, we build things that matter. More and more we are seeing software becoming an integral part of any business wanting to do better, grow faster, and offer their customers “one source of truth”. We know the power of incredible software and the potential it has to change the world, we’ve been at it since 2008 building platforms for fintech start-ups, mining giants, pioneering entrepreneurs and telecom companies. Behind our culture is an all encompassing passion to share the agony and the ecstacy in building our client’s vision. Our greatest stories started out as an idea and a dream. Those dreams became market leaders such as Howler and Resource Guru. Our name hints at ‘The Singularity’ - the moment that will trigger an explosion in technological advancement. It is our silent-nod to push the tech-envelope every single day. We want more for our clients and so we do more. Because we believe in the power of technology and its capacity to unleash change that can make the world a better place.
