Senior Full-Stack Software Engineer (Python / Django / React / Next.js)

About the Company

We are a Toronto-based technology startup developing AI-powered SaaS and marketplace software.

Our web platform and iOS/Android applications are already live, with real businesses and customers using our products. We are now focused on improving our existing systems, strengthening reliability, and rapidly delivering new features based on real user feedback.

We are seeking a hands-on Senior Full-Stack Software Engineer with strong backend expertise to take ownership of our existing production codebase, solve complex technical problems, and help establish reliable engineering practices within a small development team.

We value engineers who combine strong technical judgment with practical execution. This position is ideal for someone with experience building and maintaining production applications who enjoys solving real problems, writing code, and shipping complete features.

This is a hands-on engineering role, not a purely managerial, architectural, or advisory position.

Key ResponsibilitiesBackend Development & System Architecture

• Develop, maintain, and optimize our existing Python / Django / Django REST Framework backend and PostgreSQL database.
• Design and implement complex business logic, REST APIs, authentication, authorization, and data workflows.
• Review and improve existing architecture, database structures, code maintainability, performance, and security.
• Plan and execute database changes and migrations with appropriate testing, data integrity checks, and rollback strategies.
• Independently investigate and resolve complex backend issues, recurring bugs, performance problems, and integration failures.
• Integrate and maintain third-party services, AI APIs, payment systems, and messaging solutions.
• Support production reliability through appropriate logging, monitoring, testing, and deployment practices.

Hands-On Full-Stack Development

• Independently deliver complete features across backend, database, APIs, and frontend.
• Develop and improve web applications using TypeScript, React, and Next.js.
• Implement accurate frontend UI, including layouts, styling, responsive design, forms, dashboards, and interactive components.
• Pay attention to UI details such as spacing, typography, validation, loading states, error handling, and user interactions.
• Debug and resolve issues across frontend, backend, database, and API layers.
• Maintain consistency between web and mobile applications.
• Work effectively within an existing codebase, prioritizing practical improvements over unnecessary rewrites.
• Complete assigned functionality through development, self-testing, deployment, and verification.

Code Quality & Engineering Practices

• Review code and identify potential defects, technical risks, and opportunities for improvement.
• Support other developers through technical guidance and actionable code reviews.
• Write maintainable, well-structured code and meaningful automated tests.
• Follow and improve practical Git, pull request, testing, and CI/CD workflows.
• Troubleshoot production issues, identify root causes, and implement reliable fixes.
• Balance development efficiency, code quality, security, and long-term maintainability.

Product Development & Collaboration

• Work directly with the founder and development team to translate business requirements into practical technical solutions.
• Identify missing requirements, edge cases, and technical risks before implementation.
• Break down complex features into manageable tasks and provide realistic delivery estimates.
• Communicate progress, blockers, and technical decisions clearly and concisely, including to nontechnical stakeholders.
• Take ownership of technical tasks rather than relying on detailed step-by-step instructions.
• Adapt to evolving requirements and priorities in an early-stage startup environment.

Required Qualifications

• 6+ years of professional software development experience, including substantial hands-on full-stack development.
• Proven experience independently delivering and maintaining production applications or complex business modules.
• Strong practical experience with Python, Django, and Django REST Framework in production environments.
• Strong TypeScript, React, and Next.js development skills.
• Solid PostgreSQL knowledge, including relational data modeling, transactions, migrations, indexing, and query optimization.
• Experience designing, implementing, and troubleshooting R…