Diego Varussa Pereira

Diego Varussa Pereira

Senior Backend Engineer | Cloud Architect | Node.js, TypeScript, Microservices | API | AWS & Azure | Scalable Systems
Maringá, Paraná, Brazil | diegovarussa@gmail.com | linkedin.com/in/diego-varussa | github.com/diegovarussa

Professional Summary

With over 14 years of experience, I specialize in building high-scale, cloud-native applications that align technical excellence with business goals. As a Senior Engineer and Architect, I transform complex legacy debt into streamlined, high-performance systems using Clean Architecture and scalable design.

My career is defined by measurable impact, including slashing platform latency by 97% (5 seconds to 150ms) and reducing data processing times by 98%. By migrating monoliths to Microservices and Serverless architectures, I have consistently optimized performance while achieving cloud cost savings of up to 75%.

My core stack features Node.js, TypeScript, and NestJS, supported by deep expertise in AWS and Azure. I architect everything from real-time Forex engines to automated infrastructure via CDK and Terraform, leveraging Kubernetes (EKS/AKS) and CI/CD to build resilient, developer-friendly ecosystems.

I aim to lead high-impact transformations for organizations, focusing on engineering adaptable, resilient platforms capable of handling intense transactional loads and evolving market demands.

Skills

Backend Node.js · TypeScript · JavaScript · PHP · NestJS · GraphQL · REST APIs · Microservices
Frontend Vue.js · Quasar Framework · Electron
Cloud & DevOps Amazon Web Services (AWS) · Google Cloud Platform (GCP) · Microsoft Azure · Kubernetes · CI/CD · DevOps
Data MongoDB · MySQL
Architecture System Architecture · Microservices · Project Leadership · AI
Frameworks Zend Framework 2 · Zend Expressive

Professional Experience

Senior Software Engineer Jan 2025 – Present
DIEGO VARUSSA PEREIRA LTDA Maringá, PR
  • Led the full lifecycle of an Electron desktop application featuring an in-game overlay, leveraging AI-driven development with Claude to accelerate complex feature prototyping and maintain a continuous delivery cycle.
  • Architected and implemented a scalable full-stack solution using NestJS and Apollo GraphQL on the backend, integrated with Prisma ORM and MongoDB.
  • Developed the frontend using Vue.js 3 with Quasar Framework and Pinia, ensuring a multilingual, responsive, and high-performance interface.
  • Engineered a strategic infrastructure migration from Google Cloud Platform (GCP/Cloud Run) to Coolify, optimizing container orchestration and resulting in a 75% reduction in monthly cloud costs.
  • Implemented a robust log monitoring system using Axiom, with critical alerts integrated into Discord, and established secure authentication flows via OAuth2 with direct integration into the Discord ecosystem.
Senior Software Engineer Jul 2020 – Dec 2024
Geeklys Tokyo, Japan
  • Revolutionized the performance of the Scholarship Matching platform by diagnosing critical latency bottlenecks, implementing advanced GraphQL caching strategies, and migrating services from AWS Lambda to container architecture on App Runner, reducing response time from 5 seconds to 150ms (97% optimization).
  • Created an AWS infrastructure for trading analysis (Forex) capable of processing hundreds of events per second, using a stack based on SNS, SQS, DynamoDB, and ECS, ensuring high availability and data integrity under intense transactional load.
  • Standardized resource provisioning through AWS CDK (Infrastructure as Code), ensuring the entire network (VPC), security (Cognito/API Gateway), and storage (S3) were managed via code, eliminating manual configuration errors.
  • Established observability dashboards in Grafana integrated with CloudWatch, allowing real-time visualization of service health metrics and immediate response to failures.
Cloud Infrastructure Engineer Sep 2019 – May 2020
Colorkrew Inc. Tokyo, Japan
  • Designed and deployed Kubernetes clusters (AKS) on Microsoft Azure, configuring the entire internal network topology and Ingress policies, and establishing Auto-scaling rules to ensure application resilience.
  • Developed modular CI/CD pipelines using Terraform and Helm, enabling standardized automated deployments in multi-cloud environments (Azure/AWS) and reducing friction between development and operations teams.
  • Implemented rigorous access controls, network security, and monitoring within the Kubernetes ecosystem, ensuring compliance with cloud security best practices.
Senior Software Engineer Nov 2017 – Jun 2019
Mobingi, Inc. Tokyo, Japan
  • Identified critical maintenance flaws in legacy billing systems and led the migration from an EC2 monolith to a Microservices and Serverless (AWS Lambda) architecture on demand, which reduced cloud operating costs by 40%.
  • Architected a RESTful API Gateway under Clean Architecture principles, achieving 100% integration test coverage with Postman and standardizing error contracts to facilitate integration between internal services.
  • Developed internal telemetry tools for Kubernetes, optimizing the debug flow and increasing bug resolution speed by 60%, and implemented CI/CD pipelines via AWS CodePipeline for independent deploys.
  • Performed profiling and refactoring of an Application Lifecycle Management (ALM) platform, using clean architecture principles to identify code bottlenecks and optimize algorithms, resulting in a 90% reduction in API response time.
Software Engineer Sep 2015 – Sep 2017
LinkPro Tokyo, Japan
  • Developed a management platform for IoT devices equipped with sensors (temperature, motion, and humidity) for elderly monitoring, using Zend Expressive and Vue.js for real-time data visualization.
  • Designed multi-platform applications with Electron, integrating with proprietary C++ image processing engines focused on sharpness and visual optimization algorithms.
  • Developed web control panels embedded directly into security camera hardware, using standard web technologies (HTML/CSS/JS) for low-consumption interfaces.
Software Engineer Jan 2013 – Aug 2015
EC-Giken Santos, São Paulo, Brazil
  • Refactored data import processes for the Magento platform (EAV model), reducing processing time from 20 hours to just 20 minutes (98%) through optimized scripts and database tuning.
  • Developed complex modules for Magento and Zend Framework 2, creating centralized systems for automatic inventory management and product listing on Amazon JP and Rakuten marketplaces.
Software Engineer Jul 2011 – Nov 2012
Inove sua Escolha Maringá, Paraná, Brazil
  • Acted as Project Leader, managing task distribution for developers and providing technical mentorship to junior professionals, ensuring technical quality and team growth.
  • Led the implementation of a new base framework (PHP/CodeIgniter) with a focus on security and best practices, resulting in the total eradication of breaches in legacy systems that suffered recurring attacks.
  • Developed REST APIs for integration with mobile applications and managed the integration of multiple payment gateways with credit card operators.
Software Engineer Jan 2011 – Jun 2011
Hnet Websites Maringá, Paraná, Brazil
  • Worked on the development and evolutionary maintenance of a robust platform for automated website generation, using PHP and MySQL to ensure scalability and speed in delivering new templates.
  • Implemented online payment system integration through PagSeguro, enabling secure and automated checkout flows for the sale of products and services online.
  • Optimized frontend interfaces using HTML, CSS, and JavaScript, focusing on cross-browser compatibility and improving the end-user experience.

Education

Specialization in Web Systems Development, Web — Universidade Estadual de Maringá (2011 – 2013)
Web Design and Programming, Web — Universidade do Sul de Santa Catarina (2008 – 2011)

Certifications

Node.js Intermediate
JavaScript Intermediate

Languages

English Professional Working
Portuguese Native or Bilingual