- Depth-First Search
Follow one path to its end, then back up and try the next. The same code as BFS with the queue swapped for a stack — the traversal strategy IS the container. Recursive and iterative forms, cycle detection, and how to choose between DFS and BFS.
- Spring Boot – Interview Questions
Senior-level questions and answers, every one drawn from a real decision or a real bug in the pizza codebase rather than from a list. Auto-configuration, bean scopes, the proxy rule, transactions, N+1, stateless auth, and the trade-offs an interviewer is actually listening for.
- Python Advanced – Machine Learning
A first model, end to end and actually run: load the data, split it properly, fit a classifier, and measure it with something better than accuracy. What the workflow is, what the vocabulary means, and the leakage mistake that flatters every beginner.
- Python – Best Practices
The conventions that make Python read like Python — PEP 8 and the formatter that enforces it, naming, EAFP over LBYL, comprehensions over loops over map, and the handful of habits that separate working code from code someone else can maintain.
- Frontend Dev – Authentication and Security in the Browser
Everything the browser runs is public, so a frontend guard is a courtesy and never a control. Login flows, where to put a token and the real trade between localStorage and an HttpOnly cookie, restoring a session on refresh, XSS and CSRF in the terms that actually bite, and what a Content-Security-Policy buys you.