portnov057

Designed and shipped a wallet-native auth system on Solana: Sign-In-With-Solana-style signed challenges with domain / origin / host / network binding, Redis-backed single-use nonces, ed25519 signature verification (tweetnacl), and split access/refresh JWT rotation (HS256, 15m / 30d) with bcrypt-hashed refresh tokens and a bounded per-device session model in MongoDB. Architected the App Router codebase around feature-sliced domains with strict UI / services / persistence boundaries, enforced by type-strict schemas and Zod validation at every I/O edge. Owned an interactive Three.js / R3F pipeline with Drei and React Spring for GLB and USDZ scenes, deterministic loading, timeout fallbacks, and Safari-AR parity — holding a stable frame budget across desktop and mobile. Hardened the API surface: host / origin / referer guards, Upstash-based IP rate limiting, CSRF-safe atomic nonce consumption, geo-IP session enrichment, and structured pino logging. Built the data and state layer for server-first caching, optimistic mutations, and split transient / durable state between in-memory and document stores.

Replaced a legacy wallet connector with a custom integration, scaling supported wallets from 8 to 100+ across several dApps and contributing to a reported 254% user-base increase. Shipped production interfaces for wallet authentication, token operations, payment flows, and NFT marketplace UX. Owned build configuration, bundle optimization, CI/CD pipelines, and multi-environment deployments for a small product team.

Built the main website for a WAX play-to-earn project end-to-end: frontend, backend integration, wallet auth, and production deploy. Delivered the user-facing platform with React, Wax.js, Anchor Link, Node.js, and Express.js. Operated the stack on a VPS with Nginx routing and delivery tuning; scaled to 10,000+ users and $241,525+ in marketplace turnover.