Senior Full Stack Developer — Two-Sided Transport Marketplace (Web + Mobile App)
Budget: $15,000 – $35,000 AUD
We are building a two-sided transport and logistics marketplace. Customers post jobs, verified providers bid, funds are held until delivery is confirmed, then released less platform commission. Responsive web platform plus iOS and Android, shared backend and API.
This is not a booking app with a payment button. The difficult parts:
PAYMENTS
Multi-party payments, funds held from customer payment until delivery confirmed
Platform commission calculated and deducted on release
Full refunds, partial refunds, partial releases after commission is applied
Payout reversals, failed payouts, chargeback handling
Tax invoicing across three parties
DISPUTES AND EVIDENCE
Structured dispute workflow that freezes funds mid-transaction
Evidence capture at pickup and delivery: photos, structured condition records, proof of delivery, digital signature
Admin resolution: full release, partial refund, full refund, continued hold
Full audit trail on every financial decision
MARKETPLACE CORE
Provider onboarding, document verification, expiry tracking, admin approval
Job posting with category-specific requirement sets
Competitive bidding and provider selection
Route and date based job discovery
Live GPS tracking on active jobs
In-platform messaging with contact-detail blocking
Ratings and reviews
Full admin console: users, jobs, payments, payouts, disputes, reporting
REQUIRED SKILLS
Full stack: backend API, responsive web front end, cross-platform mobile
Relational database design for transactional and financial data
Third-party API integration: payments and connected accounts, maps and geocoding, push notifications, SMS, email, cloud storage, government verification lookups
Webhook handling, background job processing, real-time updates
Cloud deployment, CI/CD, monitoring, security hardening
WHO WE ARE LOOKING FOR
You have personally shipped at least one live marketplace that moves money between three parties — payer, payee and platform — with funds held and a working refund path. E-commerce stores, booking sites, directory listings and CMS builds do not qualify. Please do not bid if that is the closest thing in your portfolio.
HOW TO BID
Bids that do not answer all three questions will not be reviewed. No templates.
Name a platform you built that holds funds between two parties and releases them on a condition. Live URL or app store link, your specific role, and who else was on the team.
A job is $1,000. Customer pays, funds are held, provider delivers, customer disputes claiming partial damage. You resolve it as a 40% refund. Walk through what happens to the money original charge, platform commission, provider payout, refund and name the specific API calls or objects you would use.
What is the hardest part of building escrowstyle flows on a mainstream payment provider, and what have you seen go wrong in production?
PROCESS
Shortlisted bidders sign an NDA and receive the full scope document, which includes several modules not described above. From that scope you provide a fixed-price quote against a defined feature list, not an hourly estimate. Payment through Freelancer milestones. Repository access from day one, full source and IP ownership on completion.
Branding is handled separately. UX and architecture recommendations welcome, drawn from platforms you have actually built.
This is not a booking app with a payment button. The difficult parts:
PAYMENTS
Multi-party payments, funds held from customer payment until delivery confirmed
Platform commission calculated and deducted on release
Full refunds, partial refunds, partial releases after commission is applied
Payout reversals, failed payouts, chargeback handling
Tax invoicing across three parties
DISPUTES AND EVIDENCE
Structured dispute workflow that freezes funds mid-transaction
Evidence capture at pickup and delivery: photos, structured condition records, proof of delivery, digital signature
Admin resolution: full release, partial refund, full refund, continued hold
Full audit trail on every financial decision
MARKETPLACE CORE
Provider onboarding, document verification, expiry tracking, admin approval
Job posting with category-specific requirement sets
Competitive bidding and provider selection
Route and date based job discovery
Live GPS tracking on active jobs
In-platform messaging with contact-detail blocking
Ratings and reviews
Full admin console: users, jobs, payments, payouts, disputes, reporting
REQUIRED SKILLS
Full stack: backend API, responsive web front end, cross-platform mobile
Relational database design for transactional and financial data
Third-party API integration: payments and connected accounts, maps and geocoding, push notifications, SMS, email, cloud storage, government verification lookups
Webhook handling, background job processing, real-time updates
Cloud deployment, CI/CD, monitoring, security hardening
WHO WE ARE LOOKING FOR
You have personally shipped at least one live marketplace that moves money between three parties — payer, payee and platform — with funds held and a working refund path. E-commerce stores, booking sites, directory listings and CMS builds do not qualify. Please do not bid if that is the closest thing in your portfolio.
HOW TO BID
Bids that do not answer all three questions will not be reviewed. No templates.
Name a platform you built that holds funds between two parties and releases them on a condition. Live URL or app store link, your specific role, and who else was on the team.
A job is $1,000. Customer pays, funds are held, provider delivers, customer disputes claiming partial damage. You resolve it as a 40% refund. Walk through what happens to the money original charge, platform commission, provider payout, refund and name the specific API calls or objects you would use.
What is the hardest part of building escrowstyle flows on a mainstream payment provider, and what have you seen go wrong in production?
PROCESS
Shortlisted bidders sign an NDA and receive the full scope document, which includes several modules not described above. From that scope you provide a fixed-price quote against a defined feature list, not an hourly estimate. Payment through Freelancer milestones. Repository access from day one, full source and IP ownership on completion.
Branding is handled separately. UX and architecture recommendations welcome, drawn from platforms you have actually built.