Multi-vendor product marketplace development

Looking for experienced TEAM to create a B2b/B2c multi-vendor product marketplace (like DHgate,Aliexpress , Etsy, etc). Developers should have developed marketplace previously - this is very important to ensure that you have the relevant experience and have a number of marketplace examples in your portfolio to demonstrate this. (Good English language skills required.)

Please see attached full PDF specification for our project.

FUNCTIONAL REQUIREMENTS:
FRONTED Presentation layer supporting a multi-vendor marketplace on web and mobile,
including:
o Browse and search functionality
• Search should include matching, suggestions, popularity and
relevance ranking. It should search titles/metadata, categories/tags,
and full text product descriptions. It also requires ‘fuzzy matching’ and
stemming, understanding of synonyms, plurals, and spelling correction
in the search bar. Admin will need to be able to configure the search
settings in a console/admin view.
o Indexing and filtering of products, vendor shops, or results
o Individual vendor shops/pages
o Shopping cart & payment
o Subscription purchases (e.g. to purchase a product to deliver every month)
o Integrated live chat
o User registration and account management
o Messaging portal between Customer & Vendors, including communication
history and redaction of contact details (ie. mask customer e-mails from
vendors).
o Dispute module, providing chargeback/refund and escalation support
o Product rating and Reviews/feedback

BACKEND FUNCTIONALITY covering:
o Core commerce (catalog, inventory, cart, orders, payment, etc.)
o Loyalty, Referrals & Points portal
o User management (account, personal details, payment details, etc.)
o Inventory management (products, descriptions, stock, images, etc.)
o Operational communication (e-mails for password reset, purchases, etc.)
o GS1 barcode / GTIN / UPC / EAN compatibility
o CSV import for Products
o APIs/integration services for:
• Payment, including split payment between Admin and vendors, multi currency support, and charge back of disputes
• Vendor inventory management systems (e.g. Linnworks)
• Vendor fulfillment/stock/distribution systems
o Back-office functions (analytics, inventory management, etc.)

NON-FUNCTIONAL REQUIREMENTS:
o Responsive site supporting desktop, mobile and tablet
o Cross-browser compatibility (IE11+, Edge, Chrome, Firefox, Safari)
o Internationalization (multi-language support)
o Should pass an independent web accessibility assessment
o Schema markup for Rich Snippets
o AMP for Category and Product pages
o Pages should be optimized for rendering speed and tested via an independent
service (eg. Google Lighthouse, and GTMetrix)
o Should pass an independent 3rd party security/penetration test (should be included
in the quote)
o All actions by both vendors and customers on the site should be tracked in an audit
trail
o Open Graph data should be included and dynamically generated for products as they
are added
o Site should be fully secured using HTTPS (no mixed HTTP/HTTPS pages)
o Content/copy should be externalized into a CMS, not hardcoded into HTML files or
similar
o Operational documentation should be provided along with the completed system,
covering at a minimum: how the platform is architected; how it has been customised
from the base package; how to deploy it; how to troubleshoot common issues.

ARCHITECTURE / IMPLEMENTATION:
o The platform should be fully hosted within a GCP or AWS project owned entirely by
us
o The platform should scale horizontally and components should be implemented with
redundancy (ie. no single point of failure) - to be verified by an architectural review
checkpoint to be agreed during the project
o The marketplace should be accessible via our .shop domain (DNS configuration
instructions should be provided to us).
o Intuitive URL slugs should be generated based on product names
o Content such as images and videos should be optimized and delivered via CDN
o Three environments are required: development, test and production
o Where possible, configuration is preferred over customization of packages

PRICING ESTIMATION:
1. Initial set-up of our marketplace. A fixed price is required, with appropriate
milestone-based payments defined (eg. initial platform deployment, front-end
customization, deployment to test, deployment to production). Pricing should include a round of modifications/changes after launch.

METHODOLOGY:
o WE would like to arrange daily stand-ups with developers to cover Q&A and discuss
progress. Good English language skills are therefore required within the development
team.
o Bi-weekly show & tells should be arranged to demonstrate progress.
o Testing should be performed thoroughly by both agency and us prior to production
deployment.
o Tasks should be tracked within a mutually agreed project management tool (eg. Target Process, Trello).

CONFIDENTIALITY and INTELLECTUAL PROPERTY:
All work completed should be unique to us and may not be re-used with subsequent clients.