Spring Boot: Security & Advanced

Spring Boot: Security & Advanced is the second half of the Abekus Spring Boot track — built for engineers who already know how to wire up a controller and a JPA repository, and now need to take applications from "it works on my laptop" to "it survives in production". 1,600+ active MCQs cover Spring Security end-to-end, JWT, OAuth2, advanced testing (Testcontainers), Actuator & observability, caching, async, scheduling, and messaging with Kafka and RabbitMQ. Every wrong answer comes with a detailed explanation so you don't just memorize — you understand why a filter chain works the way it does, why your JWT validation broke under load, why your @Async method silently failed.

• 1,600+ MCQs, all active and mapped to the curriculum
• 11 topics, 32 subtopics — Spring Security through messaging patterns
• ~18 hours of focused practice (at ~40s per question including the explanation)
• Level: intermediate to advanced — assumes you've used Spring Boot before
• Format: free MCQ practice, instant explanations, progress tracking
• Certificate available on completion

This course is for Java backend developers preparing for senior or SDE-2/SDE-3 interviews, engineers being handed responsibility for security or observability in a Spring service, and learners who finished a fundamentals course and now hit walls every time the conversation turns to SecurityFilterChain, OAuth2 grant types, or why their Kafka consumer keeps re-reading messages. If you've never opened a Spring Boot project before, start with Spring Boot Fundamentals first — this course assumes you can read a @RestController without flinching.

The curriculum maps 1:1 to the practice bank. The 11 topics, in order:

1. Introduction to Spring Security — security fundamentals, the filter chain, SecurityContext, how Spring Security plugs into a Boot application.
2. Authentication Mechanisms — AuthenticationManager, UserDetailsService, PasswordEncoder, DAO and in-memory providers, form login, basic auth, custom login flows.
3. Authorization & Access Control — role-based access, URL-pattern authorization, method-level security (@PreAuthorize, @PostAuthorize), SpEL in security expressions.
4. JWT Authentication — token structure, signing algorithms, stateless auth, refresh-token patterns, common JWT pitfalls (algorithm confusion, expiry skew, key rotation).
5. OAuth2 & Social Login — OAuth2 grant types, Spring Security OAuth2 Client, Spring Resource Server, opaque vs JWT tokens, scope-based authorization.
6. Advanced Testing — @WebMvcTest, @SpringBootTest, MockMvc, integration testing with Testcontainers (Postgres, Kafka, Redis), slicing tests for speed.
7. Actuator & Observability — built-in endpoints, custom health indicators, Micrometer metrics, distributed tracing with Brave/OpenTelemetry.
8. Caching with Spring — Spring's cache abstraction, Redis as a cache backend, write-through / write-behind / read-through patterns, cache eviction and TTL design.
9. Async Processing & Scheduling — @Async executors, thread pool sizing, @Scheduled tasks, application events and listeners (sync vs async).
10. Spring Boot with Messaging — Spring Kafka producers and consumers, RabbitMQ & Spring AMQP, queues vs topics, common messaging patterns (work queue, pub-sub, dead-letter).
11. In Practice — concept comparisons, pattern selection, applied scenarios that mirror what interviewers actually ask.

Reading documentation gives you a vague sense that you "get it". Answering 1,600 MCQs forces you to commit. You will get questions wrong — that is the point. The explanation after each wrong answer is where the learning happens, and the active-recall loop (question → guess → explanation → reattempt later) is what locks the concept in. The depth of this course's bank means you cannot pattern-match your way through; you will eventually hit a question on filter ordering or OAuth2 PKCE that you have to think about.

A common question on interview panels: "why use Spring Security?" The bank covers this explicitly — when Spring Security pays for itself (CSRF, session fixation, password hashing, OAuth2 plumbing), and when its filter chain becomes the source of the bug rather than the solution. By the end of the course you should be able to read a custom SecurityFilterChain bean and explain what every filter does, and why.

Realistic estimate: 18 hours of focused practice. Most learners spread that over 3–5 weeks at 30–45 minutes per day. If you are prepping for a specific interview in two weeks, a 90-minute daily block will get you through it. Skipping the explanations to "just answer questions faster" defeats the entire model — read every explanation, especially on the ones you got right by luck.

• Java Fundamentals — if any of the language-level pieces (lambdas, generics, exceptions) feel shaky, fill the gaps first; security code is unforgiving when you misuse them.
• Java Concurrency & Multithreading — pairs naturally with the @Async, scheduling, and Kafka consumer topics here.
• Java Interview Mastery — for the language-level trap questions panels lean on between Spring Boot questions.

Free, no signup wall, certificate on completion. Practice openly, fail openly, learn the parts that matter.