Hi! I'm Arjay, Software Engineer and Creator. I use this space to share cool interactive tools I've built.
Want to chat with me and practice system design every day? Check out The Daily Dev, my community and app for engineers. Also available on the App Store.
Small interactive things I've built for engineers and creators. More on the way.
Browse the current tools across every layer, pick a complete stack so you don't miss a piece, and walk away with a ready-to-paste LLM prompt to help you design the whole system.
Drag-and-drop the databases, caches, queues, and runtimes you'd actually pick in 2026. Share your ranking. A cheeky way to take the temperature of the ecosystem.
Rank the 14 major programming languages. Tap any chip to see 2026 US salary, job openings, difficulty, and trend direction, all with cited sources from TIOBE, Stack Overflow, Octoverse, and Glassdoor.
Interactive simulations for six of the most common database types: relational, key-value, wide-column, object, vector, and graph. Storage, mutations, access patterns, and behavior under load.
Exactly how and what parts of your system to scale at each stage of growth. From a single VM to a distributed system.
Pick a caching strategy, change the load, watch the system respond. Cache-aside, read-through, write-through, write-behind, and refresh-ahead, with live stats and failure-mode scenarios.
From npm start on
localhost to a real HTTPS URL. Five pieces: a server, your app,
a process manager, a reverse proxy, a domain. Diagrams plus
the exact commands to run on your own box.
Free, long-form guides for engineers at every stage. Drop your email, get the PDF.
Turn your CS degree into a true competitive advantage in the 2026 job market by leveraging your real strengths: systems thinking, problem-solving, strategic decision-making, and the ability to design and lead AI-powered workflows across any team or industry.
A concise system design guide tailored to the questions you'll get in interviews and the decisions you'll make when designing real large-scale distributed systems. Not a textbook. Not a 300-page monologue on distributed systems theory. Just ~40 pages that get you where you need to be.
A playbook for ideating, planning, and building a personal project. A zero-to-one guide that covers everything from picking a tech stack to deploying and trying to get a couple users.
A week-by-week playbook for turning a big-tech internship into a return offer. Built from 3x return offers and years of mentoring interns who got theirs too. The first, middle, and final thirds, and exactly what to do in each.
The path I would tell a friend to follow if they wanted to become a backend engineer and get a job doing it. By the end you have one complete, deployed, tested service that touches almost everything a real production system does.