Senior Full-Stack Developer (Next.js / Supabase / WebRTC) – Canada Only

Project: Communication platform Location Requirement: Canada only (mandatory) Engagement Type: Ongoing, on-call + initial production launch Company Location: Canada Overview We are a Canada-based company building HZad Talk, a full-stack web platform that is already developed but not yet live. We are looking for a senior full-stack developer located in Canada to take over the existing codebase, bring the platform live, and continue supporting it as it evolves. This is long-term, ongoing work. After launch, there will be periods with minimal activity, as well as moments where fast response is required for bug fixes or urgent issues. Due to legal and contractual requirements, only developers physically based in Canada will be considered. No agencies, no offshore teams, and no subcontracting. Core Technologies You Must Be Comfortable With You don’t need to build the system from scratch, but you must be confident working with and maintaining a platform that uses: Next.js / React for a full-stack web application Supabase (PostgreSQL, authentication, storage, RLS policies) Node.js and npm-based workflows Python for backend or AI-related processing AI integrations (OpenAI APIs or similar) Real-time features (audio/video or event-driven systems) Production deployments and environment-based configuration (.env files) If you have worked on platforms involving authentication, real-time interactions, and AI-powered features, this role will feel familiar. Initial Scope (Phase 1) Review the existing codebase and documentation Prepare the application for production Deploy the platform to a live environment Validate core functionality and integrations Address known bugs and stability issues Ongoing Scope (Phase 2) Bug fixes and performance improvements Minor feature updates and refinements Emergency troubleshooting when issues arise Long-term technical ownership of the platform This role requires someone reliable who can step in quickly when needed, even though work will not be constant. -Note: There will be no fixed hours as the work would depend on the project needs. Some weeks might need 0 hours, some weeks 2 hours, some weeks 20 hours. We would expect less than 5 hours of work to be covered when requested but if more hours are required in certain weeks and the freelancer is not available for short notice, we will of course understand and be flexible around the freelancer's schedule. Requirements (Non-Negotiable) Must be located in Canada Must be able to sign Canadian contracts Strong experience maintaining and scaling full-stack platforms Comfortable inheriting and owning an existing codebase Able to work independently without hand-holding Clear and professional communication Nice to Have Experience with Supabase security policies (RLS) AI or audio processing experience Experience supporting early-stage or growing products