Senior Full-Stack Product Developer for Luxury Marketplace Pre-Launch MVP

VANDALUX is an early-stage, buyer-led luxury marketplace built around a demand-first model rather than traditional catalogue browsing. We are looking for a Senior Full-Stack Product Developer, or a very small senior-led team, to take responsibility for the design, development, testing and technical delivery of our Pre-Launch MVP.

The core product journey is:

SEARCH → POSSIBILITY → MATCH → TRANSACTION

The Pre-Launch MVP is deliberately non-transactional. It is designed to validate genuine buyer demand, seller responsiveness and the platform’s ability to generate credible Possibilities from real supply. It will not execute live purchases, seller payouts, payment-triggered reservations, transaction authentication or completed sales.

Scope

The developer will own the complete Pre-Launch MVP, including:

Full-stack web application development
Product UI design and frontend implementation
Responsive Buyer, Seller and Administration interfaces
Reusable product UI/component system
Database architecture and implementation
Authentication, role-based access and Row Level Security
Structured Buyer Search using Must Have, Prefer, Flexible and Unacceptable criteria
Seller inventory and onboarding workflows
AI-assisted data extraction/onboarding with Seller confirmation before information becomes marketplace fact
Supply and availability states
Deterministic matching and Possibility generation
Seller activation and response workflows
Persistent Search / Search Memory
Notifications and event handling
Administration and operational visibility
Analytics/event instrumentation required for Pre-Launch validation
Security, testing, deployment, documentation and technical handover

Expected technical direction: Next.js, React, TypeScript, Supabase and PostgreSQL.

Product UI responsibility — important

Product UI design is part of the developer’s scope.

A separate Brand Identity specialist will provide VANDALUX’s brand identity and brand-level visual foundations, including typography, colour, visual language and brand assets/guidance.

The developer must not assume that a finished application UI, complete screen library, Figma product UI package or ready-made product Design System/component library will be supplied.

The developer is responsible for translating the approved product requirements, workflows and Brand Identity foundations into the actual application, including screen-level Buyer/Seller/Admin interfaces, responsive layouts, navigation and interaction behaviour, interface states, loading/validation/error states and reusable product UI components.

A separate broad UX-research programme is not part of this role. The requirement is the product UI work necessary to design and implement the specified MVP correctly.

Engineering expectations

This is not a brochure website or basic CRUD build. The detailed scope requires secure and maintainable architecture, including:

Strict role and data isolation
Adversarial RLS/security testing
Explicit and auditable workflow/state transitions
Concurrency protection for sensitive state changes
Durable/auditable event history
Privacy-safe data exposure
Deterministic and explainable matching
Resilient asynchronous AI processing, including retries, failure recovery and idempotency where applicable
Least-privilege administrative permissions
Separation of notification events from delivery channels
Configuration-driven structures where appropriate
Observable Seller-response and Search/Possibility failure paths
Milestone-specific, testable acceptance criteria

Core workflows should become demonstrable through functional, clickable interfaces from the earliest relevant milestones, rather than existing only as APIs or static mock-ups. Presentation decisions should remain sufficiently separated from domain rules, application state and data architecture so later visual refinement does not require unnecessary structural rework.

Ownership and delivery

The project must be built from the beginning within VANDALUX-controlled accounts and infrastructure, including source-code repository, backend/database and deployment/production environments.

Clean technical handover and appropriate documentation are required.

Commercial structure

We are seeking a fixed-price proposal for the complete defined Pre-Launch MVP, not an open-ended hourly engagement.

Shortlisted candidates will receive the detailed VANDALUX Developer Pack containing the full product, technical, scope and acceptance baseline before submitting their final fixed-price proposal.

The final proposal must state:

Total fixed price
Realistic delivery timeline
Proposed milestones and milestone pricing
Deliverables for each milestone
Testing/QA approach
Post-delivery defect/warranty period
Any genuine technical assumptions or exclusions

Please do not submit an artificially low initial price that excludes material parts of the described scope with the expectation that they will later become paid change requests. Any matter that could materially affect price must be identified before the final fixed-price proposal is agreed.

Application requirements

Please include:

2–4 relevant applications you personally built or led, explaining your actual responsibility.
Your experience with Next.js/React/TypeScript and Supabase/PostgreSQL.
An example involving multiple user roles, permissions or RLS/data isolation.
An example where you were responsible for product UI design as well as implementation, rather than receiving complete finished screens.
Your initial view of the likely timeline and fixed-price range. This may be refined after reviewing the detailed Developer Pack.
Whether you personally will perform the work and, if not, exactly who else will be involved.

Written applications are mandatory. All assessment and candidate communication will be conducted in writing. Please do not request or propose calls, video meetings or interviews as part of the selection process.

Candidates will be shortlisted based on relevant work, technical judgement, product ownership and the mandatory written responses. Shortlisted candidates will then receive the detailed Developer Pack for their final comparable fixed-price proposal.