Senior Full-Stack Developer (Mortgage Broker Platform) - Part-time - LATAM/NA

About the project:

Non-technical founder (mortgage broker, Toronto) has built a UI mockup in Lovable for an internal mortgage operations platform — pipeline management, AI-assisted document intake, lender matching, rate feeds, and a submission workflow. The mockup is not functional; no backend exists yet. The goal is to rebuild this as a secure, functional platform, starting with a single internal user (the founder), expanding to 1-2 colleagues at his brokerage before any wider rollout. This is not a public-facing product at this stage.

What you'll do:

• Take an existing Lovable-built UI/UX mockup and build the real backend and data layer behind it
• Design and implement secure storage and handling for sensitive financial/PII documents (tax documents, employment letters, mortgage applications)
• Integrate with Velocity/Newton, the client's internal lender-submission system, via API
• Build out automated document processing and lender-matching logic
• Recommend and implement an appropriate hosting/cloud setup (client has floated Azure but has not committed)
• Plan for future integrations (DocuSign, live rate feeds from Bank of Canada / bond data)
• Work directly with a non-technical founder — translate vague product vision into technical decisions, and communicate tradeoffs clearly

Must-have:

• Strong backend engineering experience (Node.js, Python, or similar — client is stack-agnostic, wants your recommendation)
• Relational database design and management (PostgreSQL, MySQL, or similar) — will be storing pipeline data, lender status, and sensitive financial documents
• Experience designing secure systems for sensitive data (auth, encryption, access control) — ideally with some fintech, healthtech, or regulated-data background
• API integration experience (client will need you to work with an internal partner API with unknown documentation quality — comfort with ambiguous/thin API docs is essential)
• Hosting/cloud deployment experience (AWS, Azure, or GCP) — will help select and set up a secure environment; no specific vendor required
• Comfortable working with non-technical stakeholders; can drive technical decisions independently
• Available 10-15 hrs/week to start, with likely ramp to more as phases progress

Nice-to-have:

• Prior experience with Lovable, or migrating apps off no-code/low-code platforms
• Experience in mortgage, lending, or broader fintech
• DocuSign API experience
• Azure hosting experience