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Guilherme Costa - Portfolio

Software Engineer Portfolio

Software Engineer

guilhermeldcosta@gmail.com

+55 (31) 9 9169-8722

Senior Backend Developer | 08/2025 - current

Developed and orchestrated microservices processing over 10 million financial transactions daily using Spring Boot, AWS SQS, SNS, Amazon DocumentDB and Datadog;
Implemented ETL pipelines to process approximately 1 million operations per day using AWS Glue, Spark, Python, S3, Glue Catalog, Lambda, and SQS;
Optimized a contract draft recommendation system using AWS Lambda and Python, achieving response times under 2 seconds through function warm-up and multi-level caching strategies.

Full-stack developer | 01/2025 - 07/2025

Engineered automated document processing system with Spring Batch and Java 17, slashing monthly workload by 95% and saving more than 20 staff hours per month;
Migrated legacy systems from Java 6 to new architectures in Java 17, upgrading systems that handled 200 transactions per day to over 2,000 per minute;
Optimized SQL and PL/SQL queries, reducing database load by 50% and decreasing average execution time from 14 hours to 7 hours.

Full-stack developer intern | 11/2023 - 12/2024

Collaborated on implementing a secure microservices infrastructure in AWS, contributing to API Gateway integration and centralized logging configuration.

Backend intern | 08/2023 - 09/2023

Developed automated web crawlers processing over 10,000 records daily, including a specialized solution that generated R$ 20,000 in revenue for a key client, using PHP, PostgreSQL, and Puppeteer;