- Java 17 Other Improvements
Six years and three LTS releases separate Java 11 from Java 17. The headline features get their own posts; this one collects the smaller changes that arrived in between and are easy to miss entirely — several of which you have probably already benefited from without noticing. Helpful…
- Dynamic Programming
Solve each subproblem once and remember the answer. The two conditions that have to hold, top-down memoisation versus bottom-up tables, and the jump from O(2^n) to O(n) on Fibonacci. Plus coin change, knapsack, LCS and Kadane's algorithm.
- React – Refs
A ref is a value a component remembers that does not trigger a render when it changes. Reaching a real DOM node to focus, measure or scroll it, holding a timer id between renders, why reading or writing a ref during render is a bug, and how ref differs from state in one table.
- Spring Boot – Configuring the Security Filter Chain
The modern lambda DSL — WebSecurityCustomizer is gone and so is WebSecurityConfigurerAdapter. Ordering rules so a permitAll does not accidentally open an admin endpoint, disabling CSRF only where it is genuinely safe to, and making CORS and security agree instead of fighting.
- Angular – Guards, Resolvers and Lazy Loading
Keeping signed-out visitors out of the admin area, and keeping the admin area out of everyone else's download. Functional `CanActivate` guards that return a `UrlTree`, `CanDeactivate` for the checkout page's unpaid order — including how returning a promise lets it ask in a modal instead of `window.confirm` — and `loadComponent` / `loadChildren` lazy loading with proof in the build output.