Mr. Yoker
Secure ticket-purchasing system built on blockchain, issuing W3C verifiable credentials for each ticket to guarantee authenticity and prevent fraud.
I'm Carlos Andrés Montoya Tobón, a Senior Java Backend Engineer and Solutions Architect based in Medellín, Colombia. For the last 18+ years I've been designing and building Java-based platforms — from transportation management systems and telecom transactional portals to fintech PaaS and blockchain credentials.
My specialty is backend architecture with the Spring ecosystem (Spring Boot), microservices and event-driven systems — distributed messaging with Kafka and RabbitMQ, NoSQL at scale with Cassandra — deployed on AWS, GCP and Azure. As Technical Lead and Solutions Architect I've led distributed teams of up to 45 engineers, driven DevOps culture and agile delivery (certified Scrum Master), and helped organizations modernize their stacks and pipelines.
When I'm not coding, I enjoy learning about new tech with my best friends and spending time at home with my wife Viky and our two dogs, Ragnar and Leo.
Tools and technologies I use daily to design, build and operate distributed systems.
Highlights from 18+ years of building, leading and shipping software.
A focused look at the systems I have shipped recently.
Secure ticket-purchasing system built on blockchain, issuing W3C verifiable credentials for each ticket to guarantee authenticity and prevent fraud.
My engineering playbook, codified — the architecture, testing, security and clean-code standards I hold every project to, and the trade-offs behind them. Hexagonal + DDD for JVM microservices, written to be executable by engineers and AI coding agents.
Designed the architecture and components for a warehouse-management system in Peru — Keycloak-secured, Spring Boot with Kotlin and Java on Gradle, backed by PostgreSQL.
Service portal for MutualSER built as composable micro-applications with Module Federation, secured by Keycloak over a clean-architecture backend.
Predictive and arithmetic dialer for call centers, optimizing agent-to-customer connection rates through real-time pacing algorithms.
Reusable CI/CD pipeline library — parameterized GitHub Actions workflows (build, tag-filtered tests, JaCoCo coverage, OWASP scan, ArchUnit, Spotless) shared across JVM, KrakenD and NGINX projects.
AI Engineering · For your team
Senior backend engineer, full-stack (Java + React), DevOps and Java solution architect. I fit the architecture to the problem — hexagonal, microservices, event-driven or modular monolith — pairing Spring Boot and agentic workflows with Claude Code to ship production-ready software in a fraction of the time, without sacrificing testing, ADRs or observability.
Agentic workflows (discuss → plan → execute → verify) ship in hours what takes days traditionally, while preserving atomic commits and real tests.
Clean architecture, ports & adapters, ArchUnit gates and ADRs are non-negotiable — agentic speed never comes at the cost of structure.
Tests (JUnit, Karate, Testcontainers), structured logging and OpenTelemetry tracing are wired from day one, not bolted on later.
I leave your team the workflow, not a black box: the agents, skills and guidelines stay in your repo and your engineers keep using them after I'm gone.
What I offer
Custom agents and discuss→plan→execute→verify pipelines wired into your codebase — production-ready features in a fraction of the time, tests and ADRs included.
Spring AI + Qdrant retrieval and Model Context Protocol servers in Java/Kotlin that expose your internal systems and knowledge bases as first-class agent tools.
Eval harnesses, rubrics and output validation so AI features ship measured, not vibes.
Spring Boot + hexagonal from scratch with CI/CD, observability and complete testing infra.
Strangler-fig refactor of legacy Spring/Java services toward hexagonal architecture, with full test coverage and zero downtime.
Production-ready GitHub Actions templates + GitFlow + multi-cloud deploys (EC2, VPN-tunneled EC2, EKS) backed by the soldife/ci-templates toolkit.
Open to senior backend, architecture and technical leadership roles. Feel free to reach out.