# Yiğit Yalım

> Freelance full-stack software engineer based in Ankara, Turkey. Builds web and mobile applications with Next.js, TypeScript, Supabase, and Turborepo. Computer Science student graduating June 2026. Open to contract work.

## About

- Site: https://mehmetyigityalim.com
- Email: hello@mehmetyigityalim.com
- GitHub: https://github.com/yigityalim
- LinkedIn: https://linkedin.com/in/mehmetyigityalim
- Stack: Next.js App Router, TypeScript, Tailwind CSS, Supabase, tRPC, Turborepo (Bun), Vercel
- Location: Ankara, Turkey (UTC+3)
- Languages: Turkish (native), English (B), German (A1)

## Pages

- [Home](https://mehmetyigityalim.com): About, skills, recent projects, contact form
- [Projects](https://mehmetyigityalim.com/projects): Full project list with filtering (live/in-progress/open-source)
- [Hire](https://mehmetyigityalim.com/hire): Services, availability, pricing, contact
- [Share](https://mehmetyigityalim.com/share): QR code, vCard download
- [Uses](https://mehmetyigityalim.com/uses): Editor, terminal, dev tools, infrastructure, daily tools
- [Now](https://mehmetyigityalim.com/now): Current projects, learning, reading
- [Handbooks](https://mehmetyigityalim.com/handbooks): In-depth technical guides and reference material
- [Labs](https://mehmetyigityalim.com/labs): Interactive in-browser tools — crypto playgrounds, auth utilities, web fundamentals
- [Changelog](https://mehmetyigityalim.com/changelog): Notable site and project releases over time

## Handbooks

- [Cryptography Handbook](https://mehmetyigityalim.com/handbooks/cryptography-handbook): Deep dive into modern crypto primitives — ECDSA, AES-GCM, ChaCha20-Poly1305, Argon2id, X25519, HKDF. Rust, TypeScript, WebAssembly.

## Labs

- [SHA-2 Hash Lab](https://mehmetyigityalim.com/labs/sha256-hasher): Live SHA-1/256/384/512 with bit-level avalanche meter. Demonstrates determinism, fixed output size, and the avalanche effect using WebCrypto.
- [AEAD Tamper Demo](https://mehmetyigityalim.com/labs/aead-tamper-demo): AES-256-GCM encrypt + click any ciphertext byte to flip a bit. Decryption fails with "authentication failed" — visual proof of why authenticated encryption matters.
- [Password Entropy Meter](https://mehmetyigityalim.com/labs/password-entropy): Shannon-entropy-based strength estimator with crack-time projections across four attacker profiles. Computes locally, nothing sent.
- [ChaCha20 Inner State Stepper](https://mehmetyigityalim.com/labs/chacha20-internals): 4×4 ChaCha20 state matrix stepped quarter-round by quarter-round. 320 sub-ops, color-coded cell roles, auto-play at variable speed. RFC 7539 compliant (visualisation only, not a crypto primitive).
- [JWT Decoder + Verifier](https://mehmetyigityalim.com/labs/jwt-decoder): Paste a JSON Web Token, split into header/payload/signature, verify HMAC signature with a secret. Flags expired, not-yet-valid, and dangerous `alg: none` tokens.
- [Regex Tester](https://mehmetyigityalim.com/labs/regex-tester): Pattern + flag chips, live highlighted matches, capture group breakdown, replacement preview. JavaScript regex engine, browser-native.
- [CIDR Subnet Calculator](https://mehmetyigityalim.com/labs/cidr-calculator): IPv4 CIDR breakdown — network, broadcast, host range, mask, wildcard, binary breakdown, RFC 1918 classification. Handles /31 and /32 edge cases.
- [CSS Specificity Calculator](https://mehmetyigityalim.com/labs/css-specificity): Compare two selectors, see (a, b, c) tuples and which wins. Correctly handles `:where()`, `:not()`, `:is()`, `:has()`.
- [Cubic-Bezier Tester](https://mehmetyigityalim.com/labs/cubic-bezier): Shape an easing curve with two control points, scrub the timeline, see the value's progress live. Copy CSS `cubic-bezier(...)` output.
- [Color Contrast (WCAG)](https://mehmetyigityalim.com/labs/color-contrast): WCAG 2.x contrast ratio with AA/AAA verdicts for normal and large text. Live preview block, brand color presets.
- [JSON Formatter](https://mehmetyigityalim.com/labs/json-formatter): Live JSON pretty-print + collapsible interactive tree + line/col error position. Indent (2sp/4sp/tab), minify, TS type inference.
- [Base64 Encoder/Decoder](https://mehmetyigityalim.com/labs/base64-tool): Bidirectional text ↔ base64 with URL-safe variant, UTF-8 safe. File drag-drop, MIME detection, hex dump for binary payloads.
- [JWT Generator](https://mehmetyigityalim.com/labs/jwt-generator): Reverse of JwtDecoder. Payload + secret + HMAC algorithm → signed token. Auto-regenerate, exp/iat/nbf claim helpers.
- [Diff Viewer](https://mehmetyigityalim.com/labs/diff-viewer): LCS-based line diff. Unified or split view, whitespace-ignore option. For code review, manifest comparison, content drift.
- [Sorting Visualizer](https://mehmetyigityalim.com/labs/sorting-visualizer): Five sorting algorithms (bubble/insertion/selection/quick/merge) animated as bar charts with comparing/swapping/sorted state colors.
- [HMAC Lab](https://mehmetyigityalim.com/labs/hmac-lab): HMAC tag computation with naive vs constant-time comparison demo. Visualises why timing-safe equals matters.
- [Argon2id Configurer](https://mehmetyigityalim.com/labs/argon-configurer): Tune Argon2id m/t/p parameters, measure browser latency (PBKDF2 stand-in), project crack-time on RTX 4090. OWASP presets.
- [HTTP Header Analyzer](https://mehmetyigityalim.com/labs/http-header-analyzer): Paste response headers, get a security score. CSP/HSTS/Permissions-Policy parsed, missing flagged.
- [Cron Builder](https://mehmetyigityalim.com/labs/cron-builder): Parse + describe cron expressions, list next 5 runs in user TZ, interactive field builder. Compatible with QStash / Vixie cron / Kubernetes.
- [Timezone Converter](https://mehmetyigityalim.com/labs/timezone-converter): Multi-timezone clock with DST flags and work-hour overlap. IANA zone picker, datetime-local reference.

## Projects
- [create-turbo-stack](https://mehmetyigityalim.com/projects/create-turbo-stack): Open-source CLI scaffolding production-ready Turborepo monorepos. TypeScript, Node.js, Zod.
- [Occlude](https://mehmetyigityalim.com/projects/occlude): Zero-knowledge encryption platform. XChaCha20-Poly1305 + Argon2id, Rust WASM crypto engine, SvelteKit.
- [FuarCat](https://mehmetyigityalim.com/projects/fuarcat): B2B trade fair catering operations platform, multi-tenant SaaS. Next.js 15, Supabase, tRPC, Redis.
- [Cvisioner](https://mehmetyigityalim.com/projects/cvisioner): AI recruitment ecosystem, ~600K LOC, 10 apps, 14 packages. Next.js, Supabase, tRPC, Google Gemini.
- [Portfolio](https://mehmetyigityalim.com/projects/portfolio): This site. Next.js 16, React 19, Tailwind CSS 4, Contentlayer, next-intl.
- [Efsunsu](https://mehmetyigityalim.com/projects/efsunsu): Spiritual marketplace with real-time consultancy. NestJS, Socket.io, Iyzico.
- [Galerilan](https://mehmetyigityalim.com/projects/galerilan): Automotive listing image generator. Next.js, Tailwind CSS 4.
- [Kobimatik](https://mehmetyigityalim.com/projects/kobimatik): ERP solution for SMEs. React, Node.js, PostgreSQL.
- [ATU Humidor](https://mehmetyigityalim.com/projects/atu-humidor): Duty free humidor inventory & climate tracking. Next.js, Supabase.
- [Heinrich Boquoi & Sohn](https://mehmetyigityalim.com/projects/heinrich-boquoi-sohn-website): Corporate site for a German manufacturing company.
- [Warenannahme](https://mehmetyigityalim.com/projects/warenannahme): Mobile WMS for a German manufacturing facility. React Native, Expo, Supabase.

## Optional

- [RSS Feed](https://mehmetyigityalim.com/feed.xml): Project updates in RSS 2.0 format
- [Sitemap](https://mehmetyigityalim.com/sitemap.xml): Full sitemap for crawlers
- [Turkish Home](https://mehmetyigityalim.com/tr): Turkish language version of the site