Senior Next.js & Node.js Expert Needed: Fixing Broken Logic, Query & Image Processing Optimization, Server Stability & PageSpeed 100/100 (NO AI Copy-Pasters)

​ Job Overview
​We are looking for a true Senior Full-Stack Engineer (Next.js & Node.js Expert) to take over, refactor, and fully optimize our website: localxlist.org.
​ CRITICAL NOTE (PLEASE READ BEFORE APPLYING):
We are NOT looking for "vibe coders" or developers who solely rely on AI assistants (Cursor, Windsurf, Copilot, etc.) to copy-paste code without understanding core architecture. Our previous developer attempted this approach without strong hands-on Next.js/Node.js experience, resulting in severe regressions (fixing one bug broke three other features), server crashes, unoptimized image processing, and poor database queries.
​If you do not have deep, battle-tested, manual debugging experience in Next.js SSR/ISR, Node.js backend performance, and SQL/NoSQL query tuning, please do not apply.
​Scope of Work & Requirements
​1. Next.js & Node.js Architecture & Logic Refactoring
​Audit the entire Next.js and Node.js codebase to identify broken dependencies, memory leaks, and redundant logic.
​Eliminate all console errors, build errors, server-side warnings, and state synchronization bugs.
​Ensure clean code standards so that fixing one feature never breaks another part of the site.
​2. Database & Query Optimization
​Rewrite and refactor inefficient, slow, and unoptimized database queries.
​Fix N+1 query problems, improper indexing, and heavy DB locks.
​Drastically decrease Server Response Time (TTFB) and database load.
​3. Image Processing & Asset Optimization
​Refactor the current image handling & processing pipeline (uploading, compression, resizing, and serving).
​Implement efficient storage/CDN delivery and lazy loading.
​Convert all uploaded and existing images dynamically to modern formats (WebP/AVIF) without overloading the server process.
​4. Server Stability, Crash Prevention & Request Load Handling
​Resolve root causes of server downtime, timeouts, and crash spikes during request surges.
​Optimize Node.js event loop utilization, memory management, and caching (Redis or memory cache).
​Stress-test the site to ensure 99.9% uptime and instant request handling under load.
​5. Google PageSpeed Optimization (100/100 Target)
​Achieve 90–100 Google PageSpeed Insights score on both Mobile & Desktop for all key pages.
​Minify assets, eliminate render-blocking scripts, reduce JS bundle size, and optimize Critical Rendering Path (CRP).
​ Candidate Requirements
​5+ years of real hands-on experience with Next.js (App Router & Pages Router) and Node.js.
​Deep understanding of core JavaScript/TypeScript concepts, event loop, SSR, ISR, and hydration issues.
​Proven background in database query tuning and heavy media/image processing optimization.
​Ability to inspect and debug complex code manually without blindly pasting AI-generated code.
​Excellent communication, daily commit logs, and ability to work under NDA.
​ Screening Questions (How to Apply)
​To filter out automated/AI proposals, please answer these brief questions in your cover letter:
​What was the exact bottleneck when you last optimized a Next.js + Node.js app's Google PageSpeed score from