Modern, secure, high‑performance developer portfolio built with Next.js 15.5.1, TypeScript, a strongly hardened edge-first architecture & multi‑locale SEO‑optimized delivery.
Live: https://www.coldbydefault.com • Stack: Next.js 15.5.1 · React 19.1.1 · TypeScript 5.x · Tailwind 4.1.12 · shadcn/ui · Embla Carousel · Framer Motion 12.x · next-intl 4.3.5 · Prisma ORM · Neon PostgreSQL · Zod · ESLint 9.x · Vercel
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- Overview
- Technology Stack
- Key Features
- Internationalization (i18n)
- SEO & Discoverability
- Performance & Accessibility
- Architecture Overview
- API Surface
- Security & Hardening
- GitHub Actions & Automation
- Privacy & Data Handling
- Development (Local Setup)
- Quality & Tooling
- Roadmap
- License & Intellectual Property
- Contact
This portfolio serves as a professional showcase of engineering capability: performant UI, secure API integrations (GitHub, PageSpeed), accessibility‑focused design, production‑grade hardening, and now multi‑language + deep structured SEO implementation achieving a 100/100 Google Lighthouse SEO score (Sep 2025 validation). All code is proprietary and published strictly for viewing.
Core:
- Next.js 15.5.1 (App Router, Server Components, Edge runtime where applicable)
- React 19.1.1, TypeScript 5.x (strict mode)
- Tailwind CSS 4.1.12 + PostCSS
- shadcn/ui (accessible primitives)
- Embla Carousel 8.6.0 (modern carousel with autoplay)
- Framer Motion 12.x (animation system)
- next-intl 4.3.5 (runtime + server i18n)
- Vercel Hosting & Edge Network
- Vercel CRON_Jobs (Automated Background Tasks & refresh Data)
Development & Quality:
- ESLint 9.x (flat config system, TypeScript-ESLint integration)
- Strict type checking with zero
anytolerance - Enhanced import/export linting and validation
- Comprehensive type coverage for all API interfaces (
AdminStats,GitHubData,PageSpeedMetrics) - Discriminated unions for locale handling and error states
Supporting & Utilities:
- Custom hooks (device, language, theming)
- CSP + HTTP security headers configuration
- Lightweight internal rate limiting & request sanitation
- Structured SEO config & JSON-LD generators
- Zod schema validation for type-safe runtime validation
- Prisma ORM for type-safe database operations
- Neon PostgreSQL for scalable data storage
- Dynamic browser language detection & auto-switching
- Advanced middleware for locale routing & redirections
- Dynamic sitemap & robots.txt generation
User Experience & UI:
- Responsive, mobile‑first adaptive layout
- Theme switching (light/dark) with persistence
- Enhanced carousel showcases with autoplay (Embla Carousel 8.6.0)
- Animated hero, project & certification showcases
- Cookie consent banner & localized content (EN / DE / ES / SV / FR)
- Improved accessibility with ARIA support and keyboard navigation
- Browser language auto-detection with intelligent locale switching
- Advanced middleware for seamless locale routing
- Enhanced general styling & visual improvements
Content & Data:
- Dynamic project, technology, and certification data modules
- Real‑time GitHub MCP repository & profile fetch (sanitized & cached)
- Google PageSpeed Insights integration for performance transparency
- Enhanced type-safe API interfaces for all data endpoints
- Blog system with dynamic content management and filtering
- CRUD admin dashboard for comprehensive blog management
- Enhanced blog styling with error handling & fallbacks
- New dedicated pages: /media & /library for content showcase
- Dynamic sitemap & robots.txt generation for improved SEO
- Prisma ORM integration for efficient database operations
Engineering & Quality:
- Modular component architecture (segmented domains: hero, github, projects, tech, seo, ui primitives)
- ESLint 9.x flat config with strict TypeScript integration
- Enhanced type safety and performance optimizations
- Zero-tolerance policy for
anytypes across the codebase - Centralized & locale‑aware SEO handling (
SEOHead, dynamic OG tags, canonical +hreflang) - Schema.org structured data generation (Person, Breadcrumbs)
- 100/100 Lighthouse SEO score target (validated Sep 2025)
- No hydration warnings / zero console errors goal
- Comprehensive TypeScript coverage (SEO config types, i18n message surfaces, rate limiting utilities)
Security & Privacy (summary):
- Hardened headers, CSP, origin isolation mindset
- Input & error sanitization on API boundaries
- Zero hard‑coded credentials; environment isolation
- Rate limiting to mitigate abuse vectors
- Reinforced type safety to narrow attack surface (literal unions for locales & metadata)
Runtime locale negotiation with graceful fallbacks:
- Framework:
next-intl(server aware, streaming compatible) - Supported locales:
en,de,es,sv,fr - Browser Language Detection: Automatic detection & intelligent switching
- Advanced Middleware: Seamless locale routing with proper redirections
- Selection Order: Browser preference → Default
en - Message Bundles: JSON under
messages/(typed access enhancements on roadmap)
Advanced multi‑locale SEO system delivering consistent structured metadata:
- Config‑driven locale specific SEO objects
- Open Graph & Twitter card variants per locale (images, titles, descriptions)
- JSON-LD generation for Person + BreadcrumbList
- Canonical + alternate
hreflangtags - Keyword curation & skill taxonomy powering
knowsAbout - Dynamic sitemap.xml generation with automatic locale & page discovery
- Dynamic robots.txt with proper crawling directives
- Enhanced SEO improvements across all pages & components
- CSP‑compatible (no unsafe inline script proliferation)
- Verified 100/100 Lighthouse SEO score (Sep 2025) & 100 PageSpeed Insights SEO metric
Focus Areas:
- First Meaningful Paint minimization via streaming & selective client components
- Efficient image delivery (static assets + modern formats where suitable)
- Reduced JavaScript footprint (edge/server rendering bias)
- Accessible semantic structure (landmarks, labels, focus states)
High‑level structure:
app/— Next.js routing (App Router, layouts, localized paths)components/— Domain + UI abstraction layers (hero, github, ui primitives, accessibility focus)data/— Structured static metadata (projects, certifications, tech)lib/— Cross‑cutting utilities (security, SEO, rate limiting / monitoring)hooks/— Custom React hooks (language, mobile detection, client gating)public/— Static assets (images, logos, sitemap, robots)
Design Principles:
- Separation of concerns (data vs presentation)
- Minimal surface area for API routes
- Immutable, typed content modules
All endpoints are read-only and sanitized.
| Endpoint | Purpose | Notes |
|---|---|---|
/api/about |
Returns profile / about metadata | Static + typed |
/api/blog |
Blog content management and retrieval | Prisma + Zod |
/api/contact |
Securely handles contact intent (anti‑abuse) | Rate limited |
/api/github |
Fetches GitHub profile + repos (filtered) | Tokenized (env) |
/api/pagespeed |
Surfaces PageSpeed metrics | External API wrapper |
/api/admin |
Administrative operations for content | Secured endpoints |
Controls:
- Input validation & schema constraints with Zod
- Standardized error envelopes (no internal leakage)
- Rate limiting (per IP windowed)
- Type-safe database operations via Prisma ORM
Last internal assessment: 2025‑09 (latest iteration) — no known unresolved critical/high issues.
Implemented Layers (expanded in 3.1):
- Transport & Headers: HSTS, CSP, X-Content-Type-Options, X-Frame-Options (deny), Referrer-Policy, Permissions-Policy.
- Application: Sanitized inputs, explicit error redaction, avoidance of
eval/ dangerous DOM sinks, reinforced type gates (locale / SEO literal unions) reducing unchecked paths. - Operational: Secrets confined to environment variables; repository free of credentials.
- Abuse Mitigation: IP‑scoped rate limiting on sensitive endpoints.
- Dependency Hygiene: Routine audit (npm audit) — zero known CVEs at last scan; periodic verification of transitive packages relevant to security headers & i18n.
Security Posture Snapshot:
- Critical: 0
- High: 0
- Medium: 0
- Low/Informational: Monitored
Automated security and quality workflows ensuring code integrity and vulnerability management:
CodeQL Advanced Security Scanning:
- Triggers: Push to main, pull requests, scheduled weekly
- Languages: Actions, JavaScript/TypeScript, Python
- Purpose: Static analysis for security vulnerabilities, code quality issues, and potential attack vectors
- Advanced Features: Multi-language matrix analysis, configurable query packs, integration with GitHub Security tab
Dependency Review:
- Triggers: Pull requests to main branch
- Purpose: Scans dependency changes for known vulnerabilities and license compliance
- Features: Blocks PRs with vulnerable dependencies, provides detailed security reports in PR comments
- Integration: Automated comments on pull requests with dependency security analysis
Vercel CRON Jobs & Automation:
- PageSpeed Data Refresh: Automated background refresh every 12 hours (
0 */12 * * *) - Endpoint:
/api/pagespeed/refreshwith extended 5-minute execution timeout - Purpose: Keeps PageSpeed Insights data current without user-initiated requests
- Caching Strategy: 12-hour cache with 24-hour stale-while-revalidate for optimal performance
- Vercel Redirections: Advanced URL redirections & routing optimizations
- Automated Background Tasks: Comprehensive automation for data freshness & performance
- Integration: Seamless background updates maintaining data freshness for performance transparency
- No invasive tracking; minimal analytical surface.
- Cookie consent banner gating non‑essential storage.
- No third‑party ad or profiling scripts.
Proprietary code; cloning allowed for personal viewing only (no reuse / redistribution).
Prerequisites: Node 20+ (LTS recommended), pnpm or npm.
Install & Run:
pnpm install
pnpm devBuild:
pnpm build
pnpm startQuality Assurance:
# Run ESLint 9.x with flat config
pnpm lint
# Auto-fix linting issues
pnpm lint:fix
# Check for dependency updates
pnpm test-depBlog System & Content Management:
- Prisma ORM provides type-safe database operations with PostgreSQL
- Zod schema validation ensures runtime type safety for all API inputs
- Neon PostgreSQL offers scalable, managed database infrastructure
- Blog content is dynamically managed through secure admin APIs
- Full CRUD operations with proper validation and error handling
Development Workflow:
- Complete migration to ESLint flat config system (
eslint.config.mts) - Custom rule configuration for UI components vs. application code
- Enhanced import resolution and React hooks linting
- Zero-tolerance policy for
@typescript-eslint/no-explicit-any
UI Component Architecture:
- New carousel component system using Embla Carousel with autoplay
- Improved component composition patterns
- Better separation of concerns (data vs presentation layers)
- Enhanced accessibility focus states & ARIA coverage
Development Experience:
- Enhanced ESLint rules for consistent code patterns
- Improved error boundaries and type-safe error handling
- Better debugging capabilities with structured logging
- Performance monitoring with enhanced PageSpeed integration
- Expand localization (additional languages beyond 4; automated missing key detection)
- Further edge caching tuning & RUM instrumentation (privacy‑preserving)
- Enhanced visual regression / accessibility automation
- Add selective metrics dashboard (anonymized)
- Structured data expansion (Projects, Certifications)
Copyright © 2025 ColdByDefault. All rights reserved.
This repository is provided exclusively for viewing professional capability.
Restrictions (Summary):
- No copying, modification, redistribution, or derivative works.
- No commercial or personal reuse of code, assets, or design patterns.
- Use beyond viewing requires explicit prior written permission.
Refer to LICENSE & COPYRIGHT files for formal wording.
Portfolio: https://www.coldbydefault.com
Linktree: https://linktr.ee/ColdByDefault
For professional or security inquiries, reach out via the official channels listed above.
Security research note: Responsible disclosure practices appreciated. Do not attempt exploitation against production infrastructure.