Engineering With Java: Digest #74

Local variable type inference, Modular monolith, High availability Java System, Spring Boot prompts and more ...

Jan 24, 2026

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🗒️ Articles Of The Week (8)

Local Variable Type Inference in Java: Friend or Foe? : This blog explains Java’s local variable type inference (LVTI) added in JDK 10, where you can use var to let the compiler infer a local variable’s type and reduce boilerplate. It highlights that while var can simplify code, it can also make it harder to read when the type isn’t obvious, so developers should use it carefully rather than everywhere.

Modular Monolith Structure in Spring Boot Backends : This article explains how to structure a modular monolith in Spring Boot by splitting a single deployable application into domain-aligned modules with clear boundaries, instead of traditional layered packages. It emphasizes using internal APIs, a shared domain model, and tools like Spring Modulith to enforce module boundaries and improve maintainability while keeping a simple deployment unit. This approach helps teams stay organized and makes a future transition to microservices easier if needed.

Why High-Availability Java Systems Fail Quietly Before They Fail Loudly : This article discusses how high-availability Java systems usually degrade quietly over time rather than failing suddenly, with early warning signs showing as subtle JVM metric drift (e.g., latency, GC pauses) before major outages occur. It argues that static threshold alerts often miss these correlated signals and that teams should focus on understanding overall system behavior and early patterns to catch issues sooner.

Fine-tuning RAG Applications with Spring AI and Oracle AI Vector Search : This article is a practical guide for fine-tuning Retrieval-Augmented Generation (RAG) applications using Spring AI and Oracle AI Vector Search, focusing on optimizing the OracleVectorStore configuration in application.yml to improve performance and behavior. It walks through properties like index type, similarity metrics, schema initialization, connection pooling, and model settings to tailor vector search and RAG workflows for specific use cases. This setup helps integrate Spring AI with Oracle AI Database 26ai for efficient vector search-backed generative apps.

Stop Asking ChatGPT ‘Fix My Code’ — Use These 5 Spring Boot Prompts Instead : This article argues that many developers waste time asking ChatGPT to simply “fix my code,” which often leads to shallow or tutorial-level answers because the prompt lacks context or depth. It suggests using well-crafted prompts focused on design, reviews, and deeper understanding instead of surface-level fixes to get more senior-like guidance from ChatGPT. The goal is to make the AI assist like a thoughtful reviewer rather than just a syntax fixer

GC-Free Indexing and Compaction in Panama : This post shows how to build a GC-free off-heap index and compaction mechanism for a custom storage engine using Java’s Project Panama APIs, focusing on VarHandle-based hash tables to enable fast lookups without Java GC interference. It also explains adding a compactor to reclaim disk space in an append-only design, solving both slow reads and unbounded file growth in the system. This demonstrates how Panama enables systems-level programming in Java with explicit memory control.

Command completion: IntelliJ IDEA with less shortcuts : This post explains IntelliJ IDEA’s new “command completion” feature, which let us discover and run IDE actions (like refactorings, fixes, navigation, or code generation) right from the code editor by typing ... It extends normal completion so we don’t need to memorize shortcuts and helps keep our coding flow smooth.

type classes prototype: This email announces an experimental “type classes” prototype in Java, exploring a way to attach operations to types (especially numeric/value types) for flexible, generic programming. It’s an early experiment, not a formal feature.

🔥 Recently Published In-house Blogs (6)

Java Coding Question – Sneaky Enum Bug

Spring Boot Interview Question - Fix Magic Number Code Smell /Dynamic Reload

Spring Boot Interview Question: Selective Retry on Network Errors

Distributed Locking With PostgreSQL and Spring Boot

Spring Boot Interview Question - Sending Email After User Registration

Spring Boot Interview Question – Improve API Latency

▶️ Videos Of The Week (2)

Carrier Classes; Beyond Records : Covers Project Amber’s new concept of carrier classes, which generalize records by keeping a predictable, data-centric API without enforcing immutability or field-to-component mapping. Carrier classes support deconstruction, pattern matching, and reconstruction while allowing flexible internal representation and additional fields. The discussion also touches on evolving records, prefix patterns, and future JEPs for abstract records and pattern enhancements in Java.

MCP Elicitations in Spring AI: Request Missing Information from Users : This demo explains MCP elicitations, which let a server dynamically request missing information from a client during a task (like placing a coffee order) instead of failing. Using Spring AI and MCP annotations, the server defines tools and parameters, checks for missing data, and prompts the client to fill in structured forms. The client responds via the elicitations mechanism, completing the workflow and enabling the server to perform the intended action once all information is gathered.