Crypto Presale Engineer for L1 Blockchain Presale — Website & Payments Project: Freelance (remote, UK/EU time overlap if possible) • Start: ASAP Focus: Build a secure presale microsite. We’re not announcing the base chain yet. What you’ll build Presale microsite with countdown, live progress (funds raised / buyers), and tiered price ladder (price increases after time/amount thresholds). Payments: Credit cards (Stripe/Adyen) + crypto (Coinbase Commerce/BTCPay or similar) with robust webhook handling. KYC/AML integration (Persona/Sumsub), allowlists, per-user caps, sanctions screening. Allocation & vesting ledger: Off-chain database + signed receipts/vouchers for later on-chain claims once main chain is announced. Security & ops: Rate limiting/anti-bot, secret management, HSTS/CSP, audit logs, admin dashboard, exports for finance/legal. Content hooks: Easy links between the presale site and our Parallaxian Games site. Must-have skills Full-stack TypeScript: Next.js/React, Node, Postgres (Prisma a plus). Payments (cards + crypto), PCI-sane designs, idempotent webhooks. KYC/AML flows, GDPR awareness, secure authN/Z. Strong security mindset (keys, 2FA admin, rate-limits, bot defense). Nice-to-have Prior token sale/launchpad builds, vesting/claims, referrals. Experience issuing signed claim vouchers for future on-chain redemption. Deliverables Live presale MVP (countdown, price ladder, KYC, card+crypto, caps, dashboard). Admin console, monitoring, runbooks, and handover docs.