React & Node.js B2B Admin Panel: fix bugs and stabilize

We have an existing React/Node.js B2B admin panel (internal dashboard used by our operations and account-management teams) that suffers from recurring bugs, broken UI states, and unstable behavior after recent feature releases. We no longer work with the vendor responsible for this dashboard. Users report data grids that fail to load, filters and forms that silently break, we’ve also confirmed some internal reports are available to unauthorized users which is unacceptable. We are looking for an experienced engineer to systematically diagnose, reproduce, and fix these bugs, stabilize the most critical workflows, and harden the panel so new deployments stop introducing regressions — all without disrupting our team's daily operations. Deliverables Bug Triage & Reproduction: A prioritized, documented list of reported and discovered bugs, each with clear reproduction steps, severity, and root-cause notes. Bug Fixes: Verified fixes for critical and high-priority issues across the React frontend (rendering, state, forms, data grids) and the Node.js backend (API errors, validation, permissions, edge cases). Stabilization & Regression Guard: Fixes for flaky behavior plus lightweight safeguards (input validation, error handling, and targeted tests) to prevent the same bugs from recurring on future deployments. Handover Session: A 1-hour call to walk through what was fixed, known remaining issues, and recommendations for keeping the panel stable. Freelancer requirements Strong hands-on experience debugging and fixing production React and Node.js applications. Proven track record with bug fixing, stabilization, and legacy/existing codebases (not just greenfield builds). Comfortable reproducing hard-to-catch, production-only bugs and writing clear, verifiable fixes. Fluent English and clear written communication for reporting bugs and progress.