Kalenux is a software company founded in 2021. Our team of engineers, designers, and domain specialists builds intelligent web platforms, mobile applications, and developer tools, used by hundreds of thousands of people worldwide.
Each product is built by a dedicated team of engineers and domain specialists. Researched, tested, and maintained to the highest production standards.
whennotesfly.com
High-traffic editorial magazine covering thinking, learning, technology, and culture across 6 topic categories and 60+ subtopics. Developed in collaboration with professional writers and content strategists. Built with Go, PostgreSQL, Redis, and Docker for enterprise-grade performance under load.
Scientifically-grounded IQ testing platform developed with psychologists and cognitive assessment researchers. Measures 10+ cognitive domains with detailed breakdowns, percentile rankings, and adaptive difficulty across 15+ languages.
Privacy-first file converter supporting 30+ formats, engineered by our security team to run 100% client-side. No uploads, no servers, no registration. Your files never leave your device. Trusted by over 100,000 users monthly.
Certification exam prep and career success platform covering AWS, Azure, CompTIA, and more. Expert-written study guides, practice tests, interview prep, and actionable career advice for professionals who need to pass.
Specialty coffee and cafe discovery platform helping people find work-friendly spaces, hidden gems, and the best espresso in the city. Expert-written guides, curated venue profiles, and detailed filtering across multiple cities.
Fascinating wildlife content platform exploring the most bizarre and incredible animals on Earth. Expert-written articles, interactive tools, and curated galleries covering mammals, birds, reptiles, marine life, and more.
Professional writing resource platform with expert-written templates, grammar guides, and communication skills content. Email templates, business writing, letter formats, and AI writing tool reviews.
Business formation decision platform with expert-written guides on starting companies worldwide. Country-specific formation steps, corporate tax guides, free zone comparisons, and compliance checklists.
Enterprise-ready QR and barcode generator supporting QR, Code 128, EAN, UPC, and Data Matrix formats. Custom styling, camera scanning, CSV batch mode for marketing teams. Used by businesses in 40+ countries. Works offline as a PWA.
From single-page apps to complex multi-service architectures, our engineering, design, and strategy teams cover the full stack and own every part of the process.
Full-stack web apps from landing pages to complex SaaS platforms. Our engineering team uses React, Next.js, Go, and Node.js. Production-grade architecture from day one, designed to scale.
Android native and cross-platform apps with 5 published titles on Google Play. Our mobile team handles everything from UX design to Play Store submission, compliance, and post-launch support.
Scalable backend systems and REST APIs built to handle real production workloads. Our backend specialists work with PostgreSQL, Redis, Docker, and cloud infrastructure on AWS and GCP, built to last, not just to launch.
Architecture reviews, code audits, and senior technical direction at any stage. Our principal engineers provide expert guidance before you scale into expensive problems.
Every project is led by a senior Kalenux engineer. No account managers, no outsourcing, no handoffs to juniors.
Founded in Istanbul in 2021, Kalenux brings together engineers, designers, product specialists, and domain experts to build software that people genuinely rely on. Every product we ship is the result of deep research, rigorous testing, and collaboration across disciplines.
Our multidisciplinary team covers the full stack: Go, React, Node.js, Python, Java/Kotlin for Android, PostgreSQL, Redis, Docker, and AWS. For each product we build, we partner with specialists in the relevant field, from psychologists and cognitive researchers for our IQ platform, to content strategists and SEO professionals for our editorial products.
We also open-source the infrastructure we build for ourselves. Kalenuxer, our in-house Node.js build framework, powers all Kalenux web properties and is available for the wider developer community.
A Node.js-based website build system powering all Kalenux projects. Template-based, multilingual, incremental builds, and automated deployment - built in-house because nothing else did everything we needed.
Only rebuilds changed files - CSS, JS, and HTML are tracked separately with timestamp-based invalidation. On large sites this cuts build time from minutes to seconds.
Built-in i18n with JSON data files per language, supporting 15+ languages without any external dependency or translation service. Adding a new language is a matter of adding a JSON file.
Component includes, variable substitution, and automatic minification are all built in with no plugin configuration required. Reuse headers, footers, and any partial across an entire site from a single source file.
SSH/SCP deployment scripts handle build, sync, and ship in a single command - with separate modes for frontend-only changes and full container rebuilds. No CI service required for small teams.
Kalenuxer-built frontends integrate natively with Go backend templates, allowing server-side rendering with Go's html/template package alongside the static build pipeline. This makes it straightforward to mix static pages with dynamic, data-driven routes.
Every number below represents a live product in production, not a demo, not a prototype, not a vanity metric.
Kalenux is the company behind every one of these products. Each was designed, engineered, and deployed by our in-house team. No outsourcing, no white-labelling. We build what we stand behind.
From independent developers to marketing teams, here's what our users say about Kalenux products.
"The IQ test is the most thorough free assessment I've found. The domain breakdown actually tells you something meaningful, not just a single number. I've recommended it to everyone on my team."
"File Converter Free is the only tool I trust with sensitive documents. Knowing the files never leave my browser is a game-changer for our compliance team. Clean, fast, and it just works."
"We use the QR tool across our entire retail network for product labelling and campaign tracking. The batch CSV mode alone saves us hours every week. Genuinely enterprise-ready."
"When Notes Fly is my go-to for staying sharp. The depth of content and the way it's organized across topics is unlike anything else I've read regularly. It's clearly built by people who actually read."
"Kalenux built our entire platform from scratch. What impressed me most was how they handled complexity. The architecture was clean, documented, and we could hand it to our own devs without issues."
"The QR Scanner app has over 50K downloads for a reason. It's fast, offline-capable, and handles every format I throw at it. No ads, no nonsense. Exactly what a utility app should be."
Whether you're using one of our products and need support, want to partner with our team, or have a project you'd like to discuss, our team responds to every message within one business day.
Direct access to our team. No automated bots, no support ticket queues.