Senior Full Stack Blockchain Engineer | React/Next.js, TypeScript, Python, Web3, Smart Contracts

Summary Looking for a developer to help build Premium Haztrak, a blockchain-enhanced environmental compliance platform focused on hazardous-waste tracking, digital manifest workflows, regulatory audit trails, and legal chain-of-custody verification. The product is designed to help organizations manage hazardous-waste records, shipment events, signatures, corrections, supporting documents, and compliance history in a secure and legally defensible way. The key innovation is a blockchain-based proof layer that verifies record integrity without storing sensitive environmental or regulatory data directly on-chain. The initial work will focus on building a prototype/MVP that includes manifest management, document/event hashing, hash-linked chain-of-custody timelines, blockchain proof anchoring, and a verification page where users can confirm whether a record or document has been changed. # Project Overview Premium Haztrak is a modern environmental compliance platform designed to help organizations manage hazardous-waste tracking, electronic manifest workflows, and regulatory compliance records in a more secure, transparent, and legally defensible way, specifially designed for Office of Chief Counsel, PA Department of Environmental Protection, USA. The platform is built around hazardous-waste cradle-to-grave tracking, allowing generators, transporters, facilities, compliance teams, and legal professionals to manage key records, shipment events, supporting documents, signatures, corrections, and audit history in one structured system. The next phase of the project will introduce blockchain-based verification to strengthen record integrity, chain of custody, and regulatory audit readiness without exposing sensitive compliance data on-chain. # Current Version Status The current version provides the foundation for electronic hazardous-waste tracking and demonstrates how a digital system can support EPA e-Manifest and RCRAInfo-related workflows. At this stage, the platform focuses on core hazardous-waste record management, including manifest-related workflows, shipment tracking concepts, compliance documentation, and integration patterns for working with official environmental systems. The current system should be treated as the base layer for a more advanced compliance product. The goal now is to expand it into a premium version with stronger legal, audit, and verification capabilities. # New Integration Goals The main enhancement will be a blockchain-powered compliance verification layer. This blockchain layer will not store private hazardous-waste records directly on-chain. Instead, the system will generate cryptographic proofs for important documents and events, then anchor those proofs to blockchain so records can be independently verified later. # Key integration points include: Blockchain-based proof of manifest records Tamper-evident chain-of-custody tracking Hashing of documents, signatures, corrections, and shipment events Verifiable audit logs for regulatory and legal review Evidence packet generation for disputes, audits, or investigations Secure off-chain storage for sensitive data On-chain proof references for record integrity verification Compliance dashboard for high-risk, incomplete, or disputed records Core Product Features Premium Haztrak should include: Manifest and shipment management Organization and user role management Document upload and record storage Signature and approval tracking Correction and dispute history Chain-of-custody timeline Blockchain proof generation Verification page for documents and records Audit-ready PDF export Legal evidence packet generation Compliance activity dashboard Blockchain Integration Concept The blockchain component will work as a proof layer. When a critical event happens, such as a manifest being created, signed, corrected, received, or finalized, the system will generate a hash of that event or document. These hashes can be grouped and anchored to blockchain through a smart contract or verification registry. This allows a user, auditor, attorney, or regulator to later confirm whether a record matches the original verified version. The private data stays protected in the application database or secure storage. The blockchain only stores verification proofs.