Senior Full-Stack Engineer Needed — Existing Beauty-Tech Marketplace Audit

Project: LOXI — Beauty Discovery & Professional Marketplace Project type: One-time, fixed-price technical audit Experience level: Senior / Expert Current stage: Pre-launch stabilization About the Project LOXI is an early-stage beauty technology platform connecting clients with independent beauty professionals through personalized discovery, professional portfolios, service listings, and flexible booking options. The application has been developed in Replit using AI-assisted development workflows. Significant functionality has already been implemented, but I am seeking an experienced software engineer to independently evaluate the existing codebase before inviting a broader group of real users. My objective is to understand the application’s technical condition, identify launch-blocking problems, and develop a realistic stabilization plan. I am not looking for a complete rebuild, redesign, or additional feature development at this stage. Scope of Work The selected engineer will review the existing application, focusing on: 1. Architecture and Code Quality * Application architecture and maintainability * Frontend/backend communication * Code organization and dependencies * Technical debt associated with AI-assisted development * Performance and scalability risks 2. Security and Data Integrity * Authentication and session management * Client and professional role separation * Server-side permissions and access controls * Database relationships and data persistence * Sensitive data handling and potential vulnerabilities 3. Core User Experience * Client and professional registration * Onboarding and profile completion * Service listings, pricing, and portfolio management * Search and personalized discovery * Booking requests and external booking links * Navigation, error handling, and mobile responsiveness 4. Integrations and Deployment * Existing third-party integrations * Payment integration readiness, where applicable * Deployment configuration * Logging, monitoring, and error handling * Backup and recovery considerations The audit should distinguish findings verified through source-code review from issues that require runtime or production testing. Required Deliverables I expect a written technical audit containing: 1. Executive summary of overall application health. 2. Identified issues categorized as Critical, High, Medium, or Low. 3. Code references and reproducible evidence supporting significant findings. 4. Clear identification of launch blockers. 5. Security and reliability risks. 6. Recommended fixes ranked by importance. 7. Estimated effort and cost range for stabilization. 8. Recommendation on whether the existing architecture should be retained, refactored, or selectively replaced. 9. Explanation of what could not be verified within the audit scope. Please provide the findings in language understandable to a nontechnical founder. Required Qualifications * Strong React, JavaScript/TypeScript, and Node.js experience * Experience auditing existing SaaS platforms * Authentication, authorization, and database security expertise * Experience with marketplace or multi-role applications * Familiarity with Stripe and booking integrations * Ability to review AI-assisted codebases * Strong written communication Confidentiality and Ownership LOXI is proprietary software. The selected contractor must agree to reasonable confidentiality, limited-use, and intellectual-property provisions before receiving access to nonpublic source code. I prefer a sanitized, read-only code review through a company-controlled private repository. Production administrative access is not included in the initial scope. The engineer may not disclose, reuse, or upload proprietary code to external AI systems or third-party services without express authorization. All original audit deliverables will belong to LOXI under the agreed contract terms. Important Project Boundaries This engagement is audit and recommendations only. Do not modify production code, deploy changes, remove features, redesign workflows, or initiate a migration without separate written authorization. I will consider a follow-up stabilization contract after reviewing the audit results. When Applying Please include: * Your experience auditing existing React/Node.js applications. * Examples of similar projects. * An anonymized sample technical audit report, if available. * Your proposed audit process. * Your fixed-price quote. * Expected deliverables. * Any access requirements. I value thoroughness, technical judgment, transparency, and clear communication over promises of a quick or complete rebuild.