Roberto Viray II • Software Engineer & Builder

I build enterprise backends and document what I learn.

10+ years across the stack, delivering REST APIs, microservices and the web and mobile interfaces on top of them. This site is where the lessons get written down instead of forgotten.

BankingHealthcareLogisticsIoTEnterprise systems

Read my learnings View resume

TelemetryBridge.java

1@Component
2public class TelemetryBridge {
3  private final MeterRegistry meter;
4  @EventListener
5  public void onEvent(IngestEvent ev) {
6    meter.counter("sys.events")
7      .increment();
8  }
9}

sys.kernel :: readyUTF-8 • JVM 21

Currently Exploring

System Design
Cloud Architecture
Cybersecurity
IoT
Spring Boot 3
Distributed Systems

Latest Learnings

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Sep 11, 2026•1 min read

Getting Started with Spring Boot

The minimum you need to understand about auto-configuration, starters, and the application context before writing a real service.

Spring BootJava

Aug 28, 2026•1 min read

How Dependency Injection Works in Spring

Beans, the application context, and why constructor injection is the only form worth defaulting to.

Spring BootJavaArchitecture

Aug 14, 2026•1 min read

Why I Prefer PostgreSQL for Most Applications

One engine that handles relational data, JSON documents, full text search, and queues well enough to postpone every other datastore.

PostgreSQLDatabaseArchitecture

R&D

Explore all R&D

Active#001

deV633 Security Lab

An ongoing series where I learn security the way I learn everything else: break something in a lab I own, then engineer the defense.

Spring BootKeycloakDockerBurp SuiteLinux

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Active#002

deV633

This site: a static Astro publication where the Git repository is the CMS and every note is a Markdown file.

AstroTypeScriptMarkdownCloudflare Pages

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Production#003

Healthcare Management System

A patient and records management platform built on Spring Boot and Vaadin, containerized with Docker and deployed to AWS.

JavaSpring BootVaadinDockerAWS

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Technology I Work With

Java & Spring01

Java 21Spring Boot 3Spring SecurityOAuth2 Resource ServerSpring Data JPAHibernateSpring ModulithWebFluxFlywayLombokKafka

Frontend Engineering02

Vue 3TypeScriptVitePiniaVue RouterTailwind CSSAngularReactAstroStorybook

Data & Storage03

PostgreSQLSQL ServerOracleMySQLMongoDBRedisMinIOSQLite

Mobile & Desktop04

FlutterDartRiverpodDiogo_routersqfliteTauriAndroidC#

Identity & Security05

KeycloakOIDCOAuth2JWTSpring Security

Infrastructure & DevOps06

DockerDocker ComposeNginxAWSCloudflareLinuxCertbotMavenCI/CD

Testing & Quality07

JUnit 5TestcontainersArchUnitVitestPlaywrightVue Test UtilsESLintPrettier

Engineering Leadership08

ArchitectureCode ReviewMentoringAgileScrumKanban

10+ years of shipping enterprise software.

Lead full-stack roles across banking, healthcare, logistics and IoT. The full history is on the resume page, with a PDF you can download.

Open source enthusiast.

You can read the raw source and experiments directly on GitHub.

github.com/rvirayii-est