Senior Software Engineer

Wilson Sayago

Building reliable backend and full-stack systems with Java, Golang, Node.js, and React.

Illustrated portrait of Wilson Sayago coding by the Sydney harbour

About

Senior Software Engineer with 8+ years of experience building backend and full-stack systems using Java, Golang, Node.js, and React. Strong focus on microservices, API design (REST, GraphQL, gRPC), and cloud environments (AWS, GCP). Hands-on across the full delivery cycle, from system design and implementation to performance tuning and production releases, with solid DevOps practices using Docker, Kubernetes, and CI/CD pipelines.

Delivered measurable improvements in production systems, including reducing application latency from 2–3 seconds to under 1 second through query optimisation, and service-level improvements. Designed and maintained microservices platforms supporting thousands of monthly transactions, applying architecture patterns such as Hexagonal and Clean Architecture to improve maintainability, scalability, and delivery consistency. Built more reliable release processes through structured CI/CD workflows and frequent production deployments, creating systems that are easier to evolve and less likely to fail with each release.

Impact highlights

<1s
App latency (from 2–3s)
2,000+
Monthly transactions supported
<100MB
Peak memory (from ~2.5GB)
2×/week
Production deployments

Core Skills

Languages

  • Java
  • Golang
  • Node.js
  • JavaScript
  • TypeScript

Frameworks & APIs

  • Spring Boot
  • React
  • Next.js
  • NestJS
  • REST APIs
  • GraphQL
  • gRPC

Cloud & DevOps

  • AWS
  • GCP
  • Docker
  • Kubernetes
  • GitHub Actions
  • Jenkins
  • GitLab
  • SonarQube

Databases

  • PostgreSQL
  • MySQL
  • MongoDB
  • SQL Server

Architecture & Delivery

  • Microservices
  • Hexagonal Architecture
  • Clean Architecture
  • CI/CD
  • Agile
  • Scrum
  • Kanban

Professional Experience

  1. Technical Lead

    CleverIT Group

    2022Present

    • Led cross-functional engineering teams delivering backend and full-stack solutions for international trade merchandising and container validation workflows.
    • Designed and scaled microservices-based systems using Java, Golang, React, GraphQL, AWS, and GCP, supporting 2,000+ monthly transactions with improved stability and service isolation.
    • Reduced key application latency from 2–3 seconds to under 1 second through query optimisation, service refactoring, and improved data access patterns.
    • Improved production reliability and delivery consistency by strengthening CI/CD and release practices, enabling twice-weekly deployments.
    • Standardised code reviews, engineering practices, and architectural decisions to improve code quality, maintainability, and team delivery effectiveness.
    • Partnered with product and business stakeholders on prioritisation, sprint planning, and execution to deliver production-ready solutions aligned with business needs.
  2. Full Stack Developer

    CleverIT Group

    20202022

    • Delivered backend and frontend features using Java, Golang, and React, contributing to core platform functionality in agile delivery environments.
    • Assessed high resource consumption in a client platform and migrated key microservices to Golang, reducing memory usage from approximately 2.5 GB to under 100 MB for peak seasonal services while improving performance and execution efficiency.
    • Built and optimised APIs and service integrations using GraphQL and gRPC to improve communication and data exchange across distributed services.
    • Contributed to short delivery cycles by shipping features aligned with product priorities and business needs.
    • Strengthened code quality and release stability through automated testing practices and CI/CD improvements.
    • Supported maintainability and team scalability by working with reusable components and clearer service structures.
  3. Software Developer

    Ingerencia Negocios y Tecnología

    20182020

    • Built a commission and rate calculation platform using Java and Spring Boot to support business operations and complex calculation workflows.
    • Implemented automated tests with JUnit and Mockito to improve reliability, maintainability, and release confidence.
    • Improved code quality and delivery workflows using GitLab, Jenkins, SonarQube, and Jira.
    • Translated business requirements into backend logic to support accurate implementation of operational rules and processes.
  4. Full Stack Developer

    Methodo SPA

    20182018

    • Developed an inventory and restaurant sales system using Spring Boot, React, and Ruby on Rails.
    • Migrated a legacy restaurant platform from Delphi to Java and REST APIs, increasing concurrent user capacity from approximately 2–10 users to 1000+ users in high-demand operational environments.
    • Improved data synchronisation and offline upload handling, reducing inventory discrepancies in locations with unstable connectivity and improving reporting accuracy.
    • Delivered core product features in agile team environments with a focus on stability and maintainable code.

Now & Next

What I'm focused on now, what comes next, and the direction I'm building toward.

  1. 01
    NowActive

    0–3 months

    • Studying for AWS Certified Solutions Architect – Associate (SAA-C03).
    • Building agentic workflows and AI agents with Mastra.
    • AWS
    • SAA-C03
    • Mastra
    • Agents
  2. 02
    Next

    3–6 months

    • Infrastructure as Code with Terraform on real AWS workloads.
    • Production-ready agent architectures: tools, memory, evaluation, and deploy.
    • Terraform
    • IaC
    • Agentic AI
  3. 03
    Direction

    Longer term

    • Roles that combine system design, cloud architecture, and AI-assisted delivery.
    • Optional depth later: AWS Solutions Architect Professional or Security Specialty, driven by the roles I pursue.
    • Architecture
    • Leadership
    • Cloud + AI

Featured Projects

Open-source templates and libraries from GitHub

messaging

Go

library that unify methods for connect to queues like rabbitmq, pub/sub, etc.

  • Go
  • RabbitMQ
  • Messaging

hexagonal-architecture-golang

Go

hexagonal-architecture-golang

  • Go
  • Hexagonal
  • Template

hexagonal-architecture-java

Java

hexagonal architecture java

  • Java
  • Hexagonal
  • Template

base

Java

base hexagonal, mongodb

  • TypeScript
  • Hexagonal
  • MongoDB

Insights

Curated thoughts and lessons from LinkedIn

Education

Computer Engineering

Lisandro Alvarado Central-Western University

Diploma in Management and Leadership Skills

Lisandro Alvarado Central-Western University

Certifications

Oracle Certified Associate — Java SE 8 Programmer

Oracle

Google Cloud Professional Cloud Developer

Google Cloud

AWS Certified Cloud Practitioner

Amazon Web Services

AWS Certified AI Practitioner

Amazon Web Services

Let's Connect

Open to collaboration, interesting challenges, and conversations about software engineering.

sayagowilson92@gmail.com