- Spring Study Guide – Spring Boot
What Spring Boot adds to Spring and what it does not. Starters and why one dependency drags in twelve, how auto-configuration decides, what @SpringBootApplication expands to, where component scanning starts, the property source order in full, embedded servers versus a WAR, and the Boot 3 to Boot 4 changes that turn a working answer into a wrong one.
- Generics
Generics let a class or method work with a type supplied by the caller, checked at compile time. List is the everyday face of it. Writing your own is less common, and understanding erasure explains most of the surprising rules. What they buy you Two gains: mistakes move from runtime to compile…
- Backend Dev – Databases
The part of the job that bites hardest and gets taught least. Modelling a schema you can live with, the indexes that decide whether a query takes 2ms or 2 seconds, what a transaction guarantees and what it does not, ORM versus plain SQL and when to drop down, the N+1 problem, connection pools, and migrations you can run on a live table.
- Priority Queues
A queue that serves by priority rather than by arrival. What Java's PriorityQueue is underneath, the comparator that decides min-heap or max-heap, the k-largest pattern that beats sorting, and the iteration order that is not sorted and surprises everyone.
- Spring Boot – Sending Email
JavaMailSender, a MimeMessageHelper for HTML and attachments, and rendering the body from the Thymeleaf template built earlier in the track. Sending it off the request thread, and testing the whole thing against a local sink instead of a real inbox.