--- title: Best Javarevisited posts — October 2025 | daily.dev description: The most upvoted Javarevisited posts from October 2025, curated by the daily.dev community. canonical: https://daily.dev/sources/javarevisited/best-of/2025/10 twitter:card: summary_large_image twitter:site: @dailydotdev og:url: https://daily.dev/sources/javarevisited/best-of/2025/10 og:type: website og:site_name: daily.dev og:title: Best Javarevisited posts — October 2025 | daily.dev og:description: The most upvoted Javarevisited posts from October 2025, curated by the daily.dev community. og:image: https://media.daily.dev/image/upload/s--VAY5ToZt--/f_auto/v1724209435/public/daily.dev%20-%20open%20graph --- # Best of Javarevisited — October 2025 1. 1 [](https://daily.dev/posts/stop-writing-database-dependent-tests-mock-your-data-access-layer-quo7rycbz "Stop Writing Database-Dependent Tests — Mock Your Data Access Layer") Article Javarevisited · 48w Stop Writing Database-Dependent Tests — Mock Your Data Access Layer Database-dependent tests are slow, fragile, and blur the boundaries between unit and integration testing. Mocking the data access layer through interfaces and dependency injection enables fast, isolated unit tests that focus on business logic rather than infrastructure. The recommended approach is to use mocks for 90% of tests while reserving database-touching integration tests for the remaining 10%, ensuring high coverage without sacrificing development speed. 98 10 2. 2 [](https://daily.dev/posts/what-spring-boot-taught-me-about-clean-architecture-jipdjbyjf "What Spring Boot Taught Me About Clean Architecture") Article Javarevisited · 48w What Spring Boot Taught Me About Clean Architecture A developer's journey from writing monolithic Spring Boot controllers to implementing Clean Architecture principles. The piece demonstrates how to refactor tightly-coupled code into layered architecture with proper separation of concerns, showing practical examples of moving business logic from controllers to service layers. It connects Clean Architecture concepts to SOLID principles and explains how proper layering improves testability and maintainability in Java applications. 91 3 3. 3 [](https://daily.dev/posts/i-ve-read-20-books-on-ai-and-llm-here-are-my-top-5-recommendations-for-2026-tcrpr0dwe "I’ve Read 20+ Books on AI and LLM — Here Are My Top 5 Recommendations for 2026") Article Javarevisited · 46w I’ve Read 20+ Books on AI and LLM — Here Are My Top 5 Recommendations for 2026 A curated list of five essential books for learning AI and LLM engineering, covering practical topics from building and fine-tuning models to production deployment. The recommendations include hands-on guides for prompt optimization, retrieval-augmented generation, model evaluation, infrastructure design, and understanding transformer architectures from scratch. Each book emphasizes production-ready engineering practices including monitoring, cost optimization, and system design rather than pure theory. 37 4. 4 [](https://daily.dev/posts/junit-5-is-dead-long-live-junit-6--gfdepeh63 "JUnit 5 is dead, long live JUnit 6!") Article Javarevisited · 46w JUnit 5 is dead, long live JUnit 6! JUnit 6 was officially released on September 30, 2025, marking a smooth evolution from JUnit 5 rather than a disruptive overhaul. The new version requires Java 17 as baseline, unifies version numbers across Platform, Jupiter, and Vintage modules, and adds full Kotlin 2.1+ support with suspend functions. Key improvements include inherited test ordering for nested classes, explicit nullability annotations via JSPECIFY, cleaner console output with control character handling, enhanced CSV parameterized tests with text blocks and comments, and a new fail-fast execution mode. The JUnit Vintage engine for JUnit 4 tests enters deprecation, signaling the end of legacy support after twenty years. 32 5. 5 [](https://daily.dev/posts/top-5-frontend-masters-courses-for-backend-developers-in-2026-bw9cgmx77 "Top 5 Frontend Masters Courses for Backend Developers in 2026") Article Javarevisited · 47w Top 5 Frontend Masters Courses for Backend Developers in 2026 A curated list of five Frontend Masters courses specifically valuable for backend developers, covering full-stack deployment, database fundamentals, API design, DevOps infrastructure, and frontend system design. The courses focus on practical skills like server management, database optimization, production-ready API development, CI/CD pipelines, and understanding API consumption patterns from the client perspective. 25 1 6. 6 [](https://daily.dev/posts/i-tried-30-coding-interview-resources-here-are-my-top-7-recommendations-for-2025-62nhcv9l6 "I Tried 30+ Coding Interview Resources — Here Are My Top 7 Recommendations for 2025") Article Javarevisited · 48w I Tried 30+ Coding Interview Resources — Here Are My Top 7 Recommendations for 2025 A comprehensive review of coding interview preparation platforms based on hands-on experience with 30+ resources. Recommends seven platforms for 2025: ByteByteGo for system design, AlgoMonster for algorithms and patterns, Educative for structured learning paths, DesignGurus for system design practice, Udemy for affordable courses, Zero to Mastery Academy for career growth, and LeetCode for problem practice. Includes current discount offers and explains selection criteria including practical learning, structured curriculum, instructor expertise, and value for money. 19 7. 7 [](https://daily.dev/posts/why-even-senior-engineers-struggle-to-pass-the-system-design-interview--nu3x1gzey "Why Even Senior Engineers Struggle to Pass the System Design Interview?") Article Javarevisited · 46w Why Even Senior Engineers Struggle to Pass the System Design Interview? Senior engineers often fail system design interviews despite real-world experience because interview success requires structured thinking, clear communication, and trade-off reasoning under time pressure—skills distinct from day-to-day work. Success comes from mastering frameworks that break problems into components (requirements, APIs, data modeling, scalability), practicing with realistic scenarios, and learning to articulate design decisions. Key preparation strategies include using structured learning platforms, practicing mock interviews, understanding fundamentals like caching and consistency models, and internalizing trade-offs rather than memorizing patterns. 18 [See all Javarevisited archives](/sources/javarevisited/best-of) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@graph":[{"@type":"CollectionPage","@id":"https://daily.dev/sources/javarevisited/best-of/2025/10#page","url":"https://daily.dev/sources/javarevisited/best-of/2025/10","name":"Best Javarevisited Posts — October 2025","description":"The most upvoted Javarevisited posts from October 2025, curated by the daily.dev community.","isPartOf":{"@type":"WebSite","url":"https://daily.dev"}},{"@type":"ItemList","@id":"https://daily.dev/sources/javarevisited/best-of/2025/10#items","numberOfItems":7,"itemListElement":[{"@type":"ListItem","position":1,"url":"https://daily.dev/posts/stop-writing-database-dependent-tests-mock-your-data-access-layer-quo7rycbz","name":"Stop Writing Database-Dependent Tests — Mock Your Data Access Layer"},{"@type":"ListItem","position":2,"url":"https://daily.dev/posts/what-spring-boot-taught-me-about-clean-architecture-jipdjbyjf","name":"What Spring Boot Taught Me About Clean Architecture"},{"@type":"ListItem","position":3,"url":"https://daily.dev/posts/i-ve-read-20-books-on-ai-and-llm-here-are-my-top-5-recommendations-for-2026-tcrpr0dwe","name":"I’ve Read 20+ Books on AI and LLM — Here Are My Top 5 Recommendations for 2026"},{"@type":"ListItem","position":4,"url":"https://daily.dev/posts/junit-5-is-dead-long-live-junit-6--gfdepeh63","name":"JUnit 5 is dead, long live JUnit 6!"},{"@type":"ListItem","position":5,"url":"https://daily.dev/posts/top-5-frontend-masters-courses-for-backend-developers-in-2026-bw9cgmx77","name":"Top 5 Frontend Masters Courses for Backend Developers in 2026"},{"@type":"ListItem","position":6,"url":"https://daily.dev/posts/i-tried-30-coding-interview-resources-here-are-my-top-7-recommendations-for-2025-62nhcv9l6","name":"I Tried 30+ Coding Interview Resources — Here Are My Top 7 Recommendations for 2025"},{"@type":"ListItem","position":7,"url":"https://daily.dev/posts/why-even-senior-engineers-struggle-to-pass-the-system-design-interview--nu3x1gzey","name":"Why Even Senior Engineers Struggle to Pass the System Design Interview?"}]},{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Sources","item":"https://daily.dev/sources"},{"@type":"ListItem","position":3,"name":"Javarevisited","item":"https://daily.dev/sources/javarevisited"},{"@type":"ListItem","position":4,"name":"Best of","item":"https://daily.dev/sources/javarevisited/best-of"},{"@type":"ListItem","position":5,"name":"October 2025"}]}]} ```