spring-boot
14 articles
Spring Boot Interview Questions for Experienced Developers, Settled by Running Them
Seven Spring Boot questions senior interviews ask, answered with real output — starting with the @Transactional method that threw and still committed.
Backend & APIsA Spring Cloud Gateway Example, Run Until Every Default Showed Itself
Spring Cloud Gateway 5.0.3 run for real: routes, timeouts, retries and a Redis rate limiter measured, plus the old property prefix it silently ignores.
Distributed SystemsMicroservices Interview Questions, Answered by Running Them
Seven microservices interview questions answered with counts from running Spring Boot services — starting with why three retries at three hops made 64 calls.
Distributed SystemsDocker Compose and Spring Boot: Let the Application Start the Database
Spring Boot can drive Docker Compose itself — verified with the log where it waits for the container to go healthy, in a project holding no datasource config.
ContainersA Spring Boot Microservices Example, and the 22 Seconds Nobody Shows You
Two services, one HTTP call, measured — including what the caller does when the other service is stopped, and when it is merely slow.
Distributed SystemsSpring Boot Logging: JSON Is One Property, and the Guard You Still Need
Structured logs without a logback file or an extra dependency, MDC keys as real JSON fields, and a measurement correcting what you were told about placeholders.
Cloud & DevOpsSpring Boot Actuator: Only One Endpoint Is On By Default
What Actuator actually exposes on a fresh application, why /actuator/info comes back empty, and the endpoint that changes a log level without a restart.
Cloud & DevOpsSpring Boot Pagination and Sorting, and the Page You Should Not Return
Pageable and Page in two lines — then the runtime warning Spring Data logs about returning Page from a controller, and the COUNT query every page costs.
Backend & APIsHow to Run a Spring Boot App as a Linux Service (and How Small a Box It Needs)
The systemd unit file for a Spring Boot jar, the one line most of them are missing, and measured answers to how much memory the thing actually uses.
Cloud & DevOpsHow to Dockerize a Spring Boot Application, and What Each Choice Costs
Four images built from one Spring Boot app, measured — 785MB down to 531MB, and why the layered build that everyone recommends does not shrink anything.
ContainersHow to Secure a Spring Boot API with JWT (Without Writing a Filter)
Spring Security already parses and validates JWTs. Here is the whole setup — two beans and one line of DSL — plus what a short example quietly defers.
Backend & APIsHow to Build a REST API in Spring Boot, Including the Failures
Build a working Spring Boot REST API — GET, POST, 201 with Location — then see what your callers actually get back when the request is wrong, and fix it.
Backend & APIsHow to Create a Spring Boot Project (and What the Generator Actually Gives You)
Create a Spring Boot project with Spring Initializr, then read every one of the ten files it writes — and find out what the 19 MB jar you build actually holds.
Backend & APIsService Discovery Using Eureka Server: How It Actually Works
How Eureka service discovery works: register, heartbeat, fetch and evict with real defaults, a Spring Boot server on port 8761, and self-preservation mode.
Distributed Systems