# Sayandeep Majumdar — Senior Software Engineer & Creator of Toolzy

> Personal engineering portfolio, production systems, and Toolzy: a 100% client-side, zero-telemetry developer tools platform.

## About the Author

- **Name**: Sayandeep Majumdar
- **Role**: Senior Software Engineer & Full-Stack Developer
- **Experience**: 9+ years building production web apps, CMS platforms, microservices, cloud infrastructure, and SEO-optimized web systems.
- **Current Organization**: Volition LLP
- **Location**: Kolkata, West Bengal, India
- **Education**: B.Tech in Computer Science & Engineering (Swami Vivekananda Institute of Science & Technology, 2012–2016)
- **Email**: sayandeepmajumdar.official@gmail.com
- **Website**: https://sayandeepmajumdar.github.io/
- **GitHub**: https://github.com/sayandeepmajumdar
- **LinkedIn**: https://www.linkedin.com/in/connectwithsayandeep/

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## Technical Stack & Expertise

- **Backend & Languages**: PHP, Laravel, Livewire, Python, Go, Java, REST APIs, GraphQL, Microservices, PHPUnit.
- **Frontend & UI**: JavaScript, TypeScript, React 19, Tailwind CSS, HTML5, CSS3, Prettier, Vite.
- **Databases & Storage**: PostgreSQL, MySQL, SQLite, IndexedDB, Redis.
- **DevOps & Cloud**: AWS (EC2, S3, IAM, CloudFront), Docker, Kubernetes, GitHub Actions CI/CD, Grafana, k6 load testing.
- **CMS & Web Delivery**: WordPress (Custom themes, plugins, ACF, Gutenberg, WooCommerce, WPML), Technical SEO, Core Web Vitals (LCP, CLS, FID/INP), 90+ Google PageSpeed target delivery.
- **Cryptography & Security**: Web Crypto API (AES-GCM, AES-CBC, RSA-OAEP, RSASSA-PSS, PBKDF2), Hash/HMAC (SHA-256, SHA-512, MD5), CSP (Content Security Policy), JWT verification.

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## Production Projects

- **Assetcomply App**: Enterprise asset-compliance application built with Laravel, Livewire, Blade, REST APIs, RFID hardware integrations, payment gateways, and database migration architecture.
- **High-Performance CMS Platforms**: WordPress platforms with custom themes, plugins, structured schema data, canonical tags, automated XML sitemaps, and responsive UI.
- **Speed & Core Web Vitals Engineering**: Sub-second load times achieved via image compression, lazy loading, script bundling, CDN caching, and modern HTTP headers.
- **Cloud & Observability Pipelines**: Infrastructure provisioning on AWS with Docker containerization, Kubernetes orchestration, and automated CI/CD deployment pipelines.

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## Toolzy — 100% Client-Side Developer Toolbox

Toolzy (`https://sayandeepmajumdar.github.io/tools/`) is a comprehensive suite of 40+ free, privacy-first developer tools, cryptography suites, diagram visualizers, formatters, and calculators running entirely in the browser. Zero data leaves the user's browser (no telemetry, no server processing, no signups).

### Developer & Coding Tools
- [JSON Formatter & Validator](https://sayandeepmajumdar.github.io/tools/developer/json-formatter): Format, validate, beautify, and minify JSON with collapsible tree explorer and line error markers.
- [YAML Formatter & Validator](https://sayandeepmajumdar.github.io/tools/developer/yaml-formatter): Multi-document YAML validation, indentation fixer, and YAML ⇄ JSON converter.
- [XML Formatter & Validator](https://sayandeepmajumdar.github.io/tools/developer/xml-formatter): XML beautifier, DOM tree visualizer, attribute sorting, and XPath copy.
- [Base64 Encoder & Decoder](https://sayandeepmajumdar.github.io/tools/developer/base64-tool): Encode and decode UTF-8 text, files, images, and Data URLs with URL-safe mode.
- [JWT Decoder & Inspector](https://sayandeepmajumdar.github.io/tools/developer/jwt-decoder): Base64URL token decoder, claims inspector (exp, iat, iss, sub), and HMAC signature verification.
- [UUID Generator & Validator](https://sayandeepmajumdar.github.io/tools/developer/uuid-generator): Generate v4 random, v7 time-ordered, and v1 UUIDs with bulk generation up to 5,000 items.
- [Cron Expression Tester](https://sayandeepmajumdar.github.io/tools/developer/cron-tester): Validate and simulate cron schedules with execution timelines and DST alerts.
- [Cron Expression Builder](https://sayandeepmajumdar.github.io/tools/developer/cron-builder): Visual scheduler form for minutes, hours, days, months, and weekdays with English translations.
- [Unix Timestamp Converter](https://sayandeepmajumdar.github.io/tools/developer/timestamp-converter): Convert Unix epoch timestamps (s, ms, μs, ns) to human dates with live clock and multi-timezone support.
- [Regex Tester & Debugger](https://sayandeepmajumdar.github.io/tools/developer/regex-tester): Live regex tester with match highlighting, capture group inspection, and substitution replace.
- [Regex Generator & AI Builder](https://sayandeepmajumdar.github.io/tools/developer/regex-generator): Build regular expressions visually from example matches and natural language rules.
- [SQL Formatter & Beautifier](https://sayandeepmajumdar.github.io/tools/developer/sql-formatter): Format SQL across PostgreSQL, MySQL, SQLite, T-SQL, BigQuery, and Snowflake dialects.
- [SQL Query Builder](https://sayandeepmajumdar.github.io/tools/developer/sql-builder): Visually construct SQL SELECT queries with interactive JOINs, WHERE filters, and GROUP BY.
- [SQL Schema Visualizer](https://sayandeepmajumdar.github.io/tools/developer/sql-visualizer): Convert SQL CREATE TABLE DDL into interactive Entity-Relationship (ER) diagrams.
- [DB Diagram & ERD Editor](https://sayandeepmajumdar.github.io/tools/developer/db-diagram): Interactive database schema modeler with DBML code sync and SQL import/export.
- [HTTP Status Code Reference](https://sayandeepmajumdar.github.io/tools/developer/http-status-codes): Searchable reference for 1xx-5xx, Cloudflare, and Nginx HTTP response codes.
- [JavaScript Formatter & Minifier](https://sayandeepmajumdar.github.io/tools/developer/js-formatter): Beautify and compress JavaScript with Prettier and Terser engines.
- [CSS Formatter & Minifier](https://sayandeepmajumdar.github.io/tools/developer/css-formatter): Beautify and compress CSS with nesting support, custom indentation, and live preview.
- [HTML Formatter & Minifier](https://sayandeepmajumdar.github.io/tools/developer/html-formatter): Beautify and compress HTML with embedded JS/CSS formatting.
- [Markdown Editor & Studio](https://sayandeepmajumdar.github.io/tools/developer/markdown-editor): Split-pane Markdown editor with GFM tables, KaTeX LaTeX math, Mermaid diagrams, and PDF export.
- [Code Snippet Manager](https://sayandeepmajumdar.github.io/tools/developer/snippet-manager): Local IndexedDB code snippet keeper with tagging, full-text search, and JSON backups.
- [Code Diff Viewer](https://sayandeepmajumdar.github.io/tools/developer/code-diff): GitHub-style syntax-highlighted diff viewer for dual files and git patches.
- [URL Encoder & Decoder](https://sayandeepmajumdar.github.io/tools/developer/url-encoder): URL component and full URI percent-encoding/decoding with batch query string editor.
- [React Component Playground & JSX Sandbox](https://sayandeepmajumdar.github.io/tools/developer/react-playground): In-browser live React 18 component editor and sandbox with live JSX compilation, split-pane resizer, console interceptor, Prettier formatting, and snippet sharing.
- [Vue SFC Playground & Composition API Sandbox](https://sayandeepmajumdar.github.io/tools/developer/vue-playground): In-browser live Vue 3 Single File Component (SFC) editor with <script setup>, Composition API, live rendering, console interceptor, and Prettier formatting.
- [SQL Playground & SQLite Database Studio](https://sayandeepmajumdar.github.io/tools/developer/sql-playground): In-browser SQLite database studio running on WebAssembly. Write SQL queries, inspect table schemas, analyze query plans, import/export .sqlite files, and share queries 100% client-side.
- [WebSocket Tester & Real-Time Client Studio](https://sayandeepmajumdar.github.io/tools/developer/websocket-tester): Client-side WebSocket testing suite and debugger. Connect to ws:// and wss:// endpoints, transmit JSON/text payloads, inspect live message streams, test heartbeats, and measure latency.
- [API Request Builder & HTTP Client Studio](https://sayandeepmajumdar.github.io/tools/developer/api-tester): In-browser REST API request builder and HTTP client. Test GET, POST, PUT, DELETE endpoints, inspect JSON responses, manage headers, query params, auth, environments, collections, and cURL commands 100% client-side.

### PDF & Document Tools
- [PDF Compressor & Document Optimizer](https://sayandeepmajumdar.github.io/tools/pdf-documents/pdf-compressor): Compress and optimize PDF file sizes directly in the browser. Downsample embedded images, strip metadata, customize compression levels, and batch download without server uploads.
- [CSV & Excel to PDF Converter](https://sayandeepmajumdar.github.io/tools/pdf-documents/csv-to-pdf): Convert CSV, TSV, and Excel spreadsheet files into styled, downloadable PDF documents with table preview and customizable page orientation.


### Security & Cryptography Tools
- [Password & Passphrase Generator](https://sayandeepmajumdar.github.io/tools/security/password-generator): Cryptographically secure password and Diceware passphrase generator with Shannon entropy metrics.
- [Hash & HMAC Generator](https://sayandeepmajumdar.github.io/tools/security/hash-generator): Compute SHA-256, SHA-512, SHA-384, SHA-1, MD5, CRC32 hashes and HMAC signatures with file chunk streaming.
- [RSA Key Generator](https://sayandeepmajumdar.github.io/tools/security/rsa-generator): Generate 2048/3072/4096-bit RSA key pairs (RSA-OAEP, RSASSA-PKCS1-v1_5, RSA-PSS) with PEM/JWK exports.
- [AES Encryption & Decryption](https://sayandeepmajumdar.github.io/tools/security/aes-encryption): Authenticated AES-GCM and AES-CBC encryption for text and files with PBKDF2 passphrase derivation.
- [CSP Generator](https://sayandeepmajumdar.github.io/tools/security/csp-generator): Build, validate, and test Content Security Policy headers with risk diagnostics and nonce calculators.

### Design & Diagram Tools
- [Color Picker & Palette Studio](https://sayandeepmajumdar.github.io/tools/design/color-picker): HEX/RGB/HSL/CMYK conversion, WCAG 2.1 contrast checker, and palette generator.
- [CSS Shadow Generator](https://sayandeepmajumdar.github.io/tools/design/css-shadow): Multi-layer box-shadow and text-shadow generator with Tailwind CSS exports.
- [CSS Border-Radius & Blob Generator](https://sayandeepmajumdar.github.io/tools/design/border-radius): 8-point elliptical CSS border-radius and organic SVG blob generator.
- [CSS Animation Studio](https://sayandeepmajumdar.github.io/tools/design/css-animation): Visual @keyframes timeline animator with cubic-bezier curve editor.
- [Tailwind Class Helper](https://sayandeepmajumdar.github.io/tools/design/tailwind-helper): Reverse CSS-to-Tailwind converter, class inspector, and color palette explorer.
- [Mermaid Diagram Studio](https://sayandeepmajumdar.github.io/tools/design/mermaid-editor): Split-pane Mermaid.js diagram editor for flowcharts, sequence diagrams, ERDs, and gantt charts.
- [Flowchart Builder](https://sayandeepmajumdar.github.io/tools/design/flowchart-builder): Visual flowchart creator with bidirectional Mermaid code synchronization.
- [System Architecture Generator](https://sayandeepmajumdar.github.io/tools/design/architecture-diagram): Convert structured text DSL descriptions into system architecture diagrams.
- [BPMN 2.0 Diagram Studio](https://sayandeepmajumdar.github.io/tools/design/bpmn-editor): Standards-compliant BPMN 2.0 modeling studio with Camunda BPMN XML and SVG export.

### Image & Vector Tools
- [JPG ⇄ PNG Converter](https://sayandeepmajumdar.github.io/tools/images/jpg-png-converter): Client-side image converter with batch ZIP extraction and export.
- [SVG Optimizer & Minifier](https://sayandeepmajumdar.github.io/tools/images/svg-optimizer): In-browser SVG cleaner and compressor with React JSX export.
- [SVG Vector Editor](https://sayandeepmajumdar.github.io/tools/images/svg-editor): Canvas vector drawing editor with live SVG code sync.
- [SVG to PNG Converter](https://sayandeepmajumdar.github.io/tools/images/svg-to-png): Rasterize vector SVGs to high-resolution PNGs with retina scaling.
- [Image Metadata & EXIF Viewer](https://sayandeepmajumdar.github.io/tools/images/image-metadata-viewer): Inspect EXIF/IPTC/GPS metadata and strip private location tags in-browser.

### Data & File Converters
- [JSON ⇄ CSV Converter](https://sayandeepmajumdar.github.io/tools/data/json-to-csv): Bidirectional JSON/CSV transformer with object flattening and delimiter controls.
- [XML ⇄ JSON Converter](https://sayandeepmajumdar.github.io/tools/data/xml-to-json): Bidirectional XML and JSON converter with CDATA and repeated sibling handling.
- [Diff Checker & Comparator](https://sayandeepmajumdar.github.io/tools/data/diff-checker): Side-by-side text, code, and JSON comparison with word-level diffing.
- [CSV & Excel to PDF Converter](https://sayandeepmajumdar.github.io/tools/data/csv-to-pdf): Convert CSV/XLSX spreadsheets to styled PDF documents in-browser.

### Text & Content Tools
- [Lorem Ipsum Generator](https://sayandeepmajumdar.github.io/tools/text/lorem-ipsum): Customizable placeholder text generator across Latin, Tech, and English themes.
- [HTML to Markdown Converter](https://sayandeepmajumdar.github.io/tools/text/html-to-markdown): Convert raw HTML or pasted rich text into clean GitHub Flavored Markdown.

### Business & Finance Tools
- [Professional Invoice Studio](https://sayandeepmajumdar.github.io/tools/business/invoice-generator): Create and export professional PDF invoices with multi-currency, discounts, and taxes.
- [Quotation & Estimate Studio](https://sayandeepmajumdar.github.io/tools/business/quotation-generator): Build estimate proposals with digital signature canvas and 1-click invoice conversion.
- [Receipt Generator Studio](https://sayandeepmajumdar.github.io/tools/business/receipt-generator): Generate Standard A4 and Thermal POS receipts with cash change calculations.
- [Business Card Studio](https://sayandeepmajumdar.github.io/tools/business/business-card-generator): Design 300 DPI print-ready double-sided business cards with vCard QR codes.
- [EMI & Loan Calculator](https://sayandeepmajumdar.github.io/tools/finance/emi-calculator): Reducing-balance loan amortization calculator with prepayment savings and PDF/CSV reports.
- [CAGR Calculator & Investment Growth Planner](https://sayandeepmajumdar.github.io/tools/finance/cagr-calculator): Calculate Compound Annual Growth Rate (CAGR), absolute returns, compounding schedules, reverse target goal planning, and multi-scenario comparison.
- [Mathlify Calculators](https://sayandeepmajumdar.github.io/tools/finance/mathlify): Financial, percentage, mortgage, and scientific formula calculators.

### Marketing & SEO Tools
- [XML Sitemap Generator](https://sayandeepmajumdar.github.io/tools/marketing/sitemap-generator): Build, validate, and export Google-compliant XML sitemaps with image/video extensions and Gzip compression.
- [Twitter/X Card Generator & Previewer](https://sayandeepmajumdar.github.io/tools/marketing/twitter-card-generator): Generate, validate, and live-preview Twitter/X Card and Open Graph meta tags (Summary, Large Image, App, Player) with live character counters, aspect-ratio diagnostics, and mobile mockup.
- [UTM Campaign URL Builder](https://sayandeepmajumdar.github.io/tools/marketing/utm-builder): Build, clean, validate, and track Google Analytics & Meta Ads campaign URLs with channel presets, space validation, auto-lowercase, QR code generation, multi-channel batch builder, and CSV export.
- [Meta Tag Generator & SERP Previewer](https://sayandeepmajumdar.github.io/tools/marketing/meta-tag-generator): Generate complete HTML meta tags, Open Graph (OG), and Twitter/X Cards with live Google SERP and social share preview cards. Export as HTML, Next.js metadata, or React Helmet.
- [SEO Content Checker & SERP Optimizer](https://sayandeepmajumdar.github.io/tools/marketing/seo-content-checker): All-in-one SEO toolkit: Title checker with pixel-width calculation, description checker, Google SERP simulator (desktop/mobile), and keyword density analyzer with N-Gram frequency.
- [QR Code Studio & Live Scanner](https://sayandeepmajumdar.github.io/tools/marketing/qr-code-generator): Generate customized high-res QR codes (URL, Wi-Fi, vCard, Email, SMS, Geo) with logos and custom colors, plus live camera scanning and image file QR decoding.
- [Wi-Fi QR Code Generator & Sign Studio](https://sayandeepmajumdar.github.io/tools/marketing/wifi-qr-generator): Generate instant Wi-Fi connect QR codes and printable guest access tent cards with WPA/WPA2/WPA3, WEP, Open networks, and hidden SSID support.
- [vCard QR Code Generator & Business Card Studio](https://sayandeepmajumdar.github.io/tools/marketing/vcard-qr-generator): Generate standard vCard 3.0 contact QR codes and printable digital business cards with multiple phone numbers, emails, addresses, job titles, and .vcf file export.
- [Barcode Studio & Live Scanner](https://sayandeepmajumdar.github.io/tools/marketing/barcode-generator): Generate standard 1D barcodes (CODE128, EAN-13, UPC-A, Code 39, ITF-14, MSI) with auto check-digit calculation and batch ZIP export, plus live camera scanning.
- [UPI QR Code Generator & Standee Studio](https://sayandeepmajumdar.github.io/tools/marketing/upi-qr-generator): Generate standard UPI payment QR codes and printable shop counter standees for GPay, PhonePe, Paytm, and BHIM with fixed amounts and custom badges.

### Productivity & Study Tools
- [Flashcards Study Studio & Spaced Repetition (SM-2)](https://sayandeepmajumdar.github.io/tools/productivity/flashcards): Study app featuring SuperMemo SM-2 spaced repetition, 3D card flips, bulk CSV import/export, text-to-speech audio, and offline localStorage persistence.
- [OmniConverter — Universal Unit Converter](https://sayandeepmajumdar.github.io/tools/productivity/unit-converter): High-precision live conversions across 12 physical dimensions (Length, Weight, Temp, Storage, Volume, Area, Speed, Pressure, Energy, Power) with simultaneous all-unit tables.
- [KeyCraft — Typing Speed Test & WPM Analyzer](https://sayandeepmajumdar.github.io/tools/productivity/typing-speed-test): Monkeytype-level typing test with real-time WPM, accuracy %, smooth caret animations, time/words/quote modes, mechanical key audio, and interactive session graphs.
- [AI Resume & Portfolio Builder](https://sayandeepmajumdar.github.io/tools/productivity/resume): Build professional ATS-friendly resumes and responsive personal portfolio websites with AI bullet point improvements, live split-pane preview, customizable templates, and 100% client-side privacy.


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## Canonical Links & Site Resources

- **Portfolio**: https://sayandeepmajumdar.github.io/
- **Toolzy Hub**: https://sayandeepmajumdar.github.io/tools/
- **XML Sitemap**: https://sayandeepmajumdar.github.io/sitemap.xml
- **Robots Policy**: https://sayandeepmajumdar.github.io/robots.txt
- **LLM Context**: https://sayandeepmajumdar.github.io/llms.txt