Final Hardening & Release: 2 Working Apps, Shared Backend & Admin Portal
Budget / Salary$550–800
TypeFreelance project
LocationRemote
Posted1 hour ago
The two apps, shared backend and admin portal are already built, working and functionally complete. We need an experienced engineer or accountable team to perform final hardening, verify release readiness and complete a controlled release.
SYSTEM
- Two apps: customer-facing and sales/service.
- One shared Node.js/Express + PostgreSQL backend with Stripe.
- A thin React admin portal using the same backend.
- React Native/Expo mobile code is part of the existing system.
- Existing source code, automated tests, CI and written release procedures will be provided under NDA. A substantial amount of code was developed with AI assistance and needs independent engineering review.
FINAL SCOPE
1. Review the existing code across both apps, backend and admin portal; produce file-specific findings, prioritize issues and fix agreed release-blocking defects.
2. Harden authentication, permissions, API access, secrets handling and applicable security issues.
3. Verify the complete Stripe payment/refund workflow end to end. Demonstrate protection against duplicate charges, request retries, repeated/delayed/out-of-order webhooks and interrupted requests, with tests and ledger evidence.
4. Check database integrity and migrations; demonstrate backup and successful restore on an isolated environment.
5. Verify key customer, service and admin journeys on real devices/browsers; resolve crashes and release-blocking failures found during acceptance.
6. Configure or validate monitoring, error reporting and alerts; provide recovery and rollback instructions.
7. Complete the owner-approved release and relevant app-store release preparation/submission, clearly identifying any account paperwork the owner must handle.
8. Provide 60 days of on-call fixes for defects in the agreed delivered scope, with stated response times.
Some existing functionality has real users. Rehearse changes on an isolated copy; no production changes without my written approval. Hardware, kiosk/terminal work and new feature development are outside this project. The estimate should be based on the existing working code and concrete findings.
DELIVERABLES AND TERMS
Written findings and agreed fixes; passing acceptance/payment tests; restore and rollback evidence; monitoring; release checklist and handoff; 60-day defect support. One named technical owner must be accountable for the complete scope, and all code reviewers/contributors must be identified and approved under NDA.
Fixed-price target: USD $500 for the work plus $50 for the 60-day support window ($550 total). Up to $800 total may be considered for a demonstrably strong record. Confirm the full price after reviewing the code under NDA, before work starts. Payment in agreed milestones with 20% held until the support window ends. Any exclusions or additional work must be agreed in writing first.
TO APPLY
- Provide two relevant shipped projects involving Node/Postgres, React Native/Expo and Stripe, and explain your exact personal contribution. Identify any stack differences honestly.
- Explain how you prove a repeated payment request or webhook cannot create a duplicate charge, and describe a payment issue you personally fixed.
- State who will review and write the code: you or named team members.
- Give your fixed-price estimate, finish timeframe, exclusions and support response times. Final scope and price will be locked after NDA and code review.
Please respond specifically to this existing, working system and final-hardening scope.
SYSTEM
- Two apps: customer-facing and sales/service.
- One shared Node.js/Express + PostgreSQL backend with Stripe.
- A thin React admin portal using the same backend.
- React Native/Expo mobile code is part of the existing system.
- Existing source code, automated tests, CI and written release procedures will be provided under NDA. A substantial amount of code was developed with AI assistance and needs independent engineering review.
FINAL SCOPE
1. Review the existing code across both apps, backend and admin portal; produce file-specific findings, prioritize issues and fix agreed release-blocking defects.
2. Harden authentication, permissions, API access, secrets handling and applicable security issues.
3. Verify the complete Stripe payment/refund workflow end to end. Demonstrate protection against duplicate charges, request retries, repeated/delayed/out-of-order webhooks and interrupted requests, with tests and ledger evidence.
4. Check database integrity and migrations; demonstrate backup and successful restore on an isolated environment.
5. Verify key customer, service and admin journeys on real devices/browsers; resolve crashes and release-blocking failures found during acceptance.
6. Configure or validate monitoring, error reporting and alerts; provide recovery and rollback instructions.
7. Complete the owner-approved release and relevant app-store release preparation/submission, clearly identifying any account paperwork the owner must handle.
8. Provide 60 days of on-call fixes for defects in the agreed delivered scope, with stated response times.
Some existing functionality has real users. Rehearse changes on an isolated copy; no production changes without my written approval. Hardware, kiosk/terminal work and new feature development are outside this project. The estimate should be based on the existing working code and concrete findings.
DELIVERABLES AND TERMS
Written findings and agreed fixes; passing acceptance/payment tests; restore and rollback evidence; monitoring; release checklist and handoff; 60-day defect support. One named technical owner must be accountable for the complete scope, and all code reviewers/contributors must be identified and approved under NDA.
Fixed-price target: USD $500 for the work plus $50 for the 60-day support window ($550 total). Up to $800 total may be considered for a demonstrably strong record. Confirm the full price after reviewing the code under NDA, before work starts. Payment in agreed milestones with 20% held until the support window ends. Any exclusions or additional work must be agreed in writing first.
TO APPLY
- Provide two relevant shipped projects involving Node/Postgres, React Native/Expo and Stripe, and explain your exact personal contribution. Identify any stack differences honestly.
- Explain how you prove a repeated payment request or webhook cannot create a duplicate charge, and describe a payment issue you personally fixed.
- State who will review and write the code: you or named team members.
- Give your fixed-price estimate, finish timeframe, exclusions and support response times. Final scope and price will be locked after NDA and code review.
Please respond specifically to this existing, working system and final-hardening scope.
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