Senior Full-Stack Engineer Needed - Planning Platform (Next.js + Webflow + OpenAI) -- 2

READ BEFORE BIDDING.
IF YOU ARE BIDDING PLEASE PROVIDE RESPONSES TO THE QUESTIONS NOTED BELOW. ANY BIDS WITHOUT DETAILED ANSWERS WILL NOT BE CONSIDERED

1. AI Application Experience
Please provide 2–3 examples of AI-powered products you have built or contributed to.
Include:
• Tech stack used
• What the AI actually did (e.g. planning assistant, recommendations, summarisation, automation)
• Your role in the project
Links to live products or GitHub are preferred.

2. OpenAI Integration
Explain how you would structure an AI planning workflow using OpenAI for a wedding planning assistant.
Please include:
• Prompt architecture
• How you would structure responses (JSON vs free text)
• How you ensure reliable outputs

3. AI Cost Control
AI costs can grow quickly in SaaS products.
How would you implement cost control and optimisation for an OpenAI-powered application?

4. AI Feature Expansion
If you were improving an AI wedding planner, what three new AI features would you introduce and why?

5. SaaS Architecture
Given the following stack:
• Next.js
• Vercel
• Supabase / Postgres
• Stripe
• Clerk authentication
• Webflow marketing site

How would you structure this as a scalable SaaS platform?

6. Webflow + Application Integration
What approach would you use to integrate Webflow with a Next.js application?
Examples may include:
• Subdomain architecture
• Micro frontends
• Reverse proxy
• Embedded applications

Explain which you would choose and why.

7. Authentication Strategy
How would you ensure authentication works correctly when integrating a Webflow marketing site with a separate application?

8. SaaS Product Experience
Please provide examples of SaaS products you have helped build.
Include:
• Subscription model
• User onboarding
• Dashboard features
• Account management

9. Performance & Scalability
If the platform grew to 50,000+ users, what would be the main scalability concerns and how would you address them?

10. Security Considerations
What security considerations are important when building a SaaS product that includes:
• User messaging
• Vendor communication
• Payments
• AI integrations

11. Development Approach
How would you structure development for the next stage of this project?
For example:
• Architecture audit
• Integration phase
• Feature roadmap

12. Code Quality & Portfolio
Please provide either:
• GitHub profile
• Code samples
• Links to production applications you’ve built


Overview

I’m building an AI-powered wedding planning platform and need a senior-level full-stack engineer to take over integration and evolution of the product.

This is not a simple embed task.

The core AI product already exists in Next.js and is deployed. A Webflow marketing site has also been built. The next stage is to properly integrate the two, refine the architecture, and continue evolving the product into a scalable SaaS platform.

I’m looking for someone who can think beyond implementation and help shape a production-ready system.

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Current Architecture

Application Layer
• Next.js 15 (App Router)
• React 19
• Hosted on Vercel
• OpenAI integration (AI wedding planner)
• Clerk authentication
• Stripe billing
• Supabase / Postgres database

Features Already Built
• AI wedding planner
• Vendor discovery
• Messaging & inquiry system
• Quote collection & negotiation
• Booking confirmation flow
• Checklist management
• User dashboard

Marketing Layer
• Webflow site
• Custom rose-glass design aesthetic
• Landing & pricing pages built
• Needs structured integration with the app

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What I Need

Phase 1 – Architectural Integration

Not just iframe insertion.

We need a proper integration strategy between Webflow and the Next.js app that:
• Preserves performance
• Maintains authentication integrity
• Avoids security policy conflicts (CSP / frame-ancestors)
• Ensures seamless UX
• Supports future feature growth

Options may include:
• Subdomain architecture
• Micro-frontend approach
• Controlled embedding
• Reverse proxying
• Or full migration strategy if appropriate

I’m open to recommendations from someone experienced.

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Phase 2 – Product Refinement & UI Evolution

The Webflow site is not final. Sections will need:
• Rebuilding and restructuring
• AI feature positioning
• Conversion-focused UX improvements
• Interactive elements
• Embedded product experiences
• Ongoing iteration

This is not a static website job — the marketing site must evolve alongside the product.

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Phase 3 – AI Feature Expansion

The AI planner is live but will require:
• Prompt refinement
• Output structuring improvements
• Performance optimisation
• Model evaluation
• Potential feature expansion (budget modelling, vendor scoring, itinerary builder, etc.)

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Technical Requirements

You must have real-world experience with:
• Next.js App Router (production deployment)
• Vercel environment management
• OpenAI API integrations
• Stripe subscription logic
• Postgres / Supabase
• Authentication systems (Clerk or similar)
• Cross-origin security & CSP handling
• SaaS architecture design

Bonus if you have:
• Experience building AI SaaS tools
• Product thinking
• Experience integrating Webflow with custom apps
• Strong UI/UX sensibility

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Not Suitable If
• You primarily build static Webflow sites
• You’ve never deployed an AI-powered production app
• You don’t understand CSP / iframe policies
• You can’t explain tradeoffs between architectural approaches

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Deliverables
• Clean integration between Webflow and application layer
• Production-ready deployment structure
• Security reviewed & hardened
• Refined AI experience
• Documentation of architecture
• Scalable foundation for growth

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Engagement

This is not a one-off task.

I’m looking for a long-term technical partner to help evolve this platform into a serious AI SaaS product.

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Budget

Open to fixed-price or milestone-based proposals.
Please propose based on scope and architecture approach.

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