Resume - Diego Varussa Pereira

Senior Software Engineer January 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 July 2020 – December 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 September 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 November 2017 – June 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 September 2015 – September 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 January 2013 – August 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 July 2011 – November 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.

Diego Varussa Pereira