Monterail is seeking a freelance Principal Software Developer to join our team. This is a senior role focused on defining technical direction, shaping systems, and making key architectural and product decisions. We need deep expertise in Ruby on Rails and React with a specific focus on designing robust admin panels and internal tooling.

What You'll Do

Define direction, shape systems, and confidently make architectural and product decisions.
Set the roadmap, identify gaps, and continuously build on top of existing systems without needing close guidance.
Design and maintain robust test suites as a core part of the build process.
Design admin panels and internal tooling for usability, maintainability, and long-term evolution.
Translate stakeholder needs into well-structured solutions across varying levels of complexity.
Bring structure to ambiguity, operate independently, and take responsibility for technical direction and outcomes.

What We're Looking For

8+ years of experience in software development.
Deep, senior-level expertise in Ruby on Rails.
Deep, senior-level expertise in React.
A proven senior profile that defines direction, not just executes.
A strong sense of end-to-end ownership.
Senior-level commitment to quality with extensive experience designing and maintaining robust test suites.
A clear and demonstrated focus on admin panels and internal tooling.
Experience working closely with internal stakeholders with strong communication skills.
Background in smaller-scale environments, such as internal tools or limited user bases.
A self-directed, senior mindset that brings structure to ambiguity and operates independently.