Leonardo Costa
Juiz de Fora,Brazil
Summary
Experienced Backend Software Engineer with 16+ years in scalable system development, specializing in .NET Core and Node.js. Skilled in Domain-Driven Design, Microservices, and Cloud-native architectures, with solid expertise in OAuth 2.0 and Event-Driven patterns.
Led impactful projects such as 'Student Map' - a personalized learning roadmap for ENEM candidates, significantly boosting user engagement, and automated AI workflows that cut content onboarding time from months to hours.
Proficient in both relational and NoSQL databases in cloud environments, committed to clean code principles and test-driven development to deliver robust solutions.
Seeking global opportunities to leverage my technical expertise and mentoring skills in innovative, agile teams focused on digital transformation and scalable backend systems.
Overview
17
17
years of professional experience
7
7
years of post-secondary education
Work history
Software Engineer
Conexia Educação
11.2022 - 12.2025
- Developed and maintained scalable backend systems using .NET Core and Node.js, improving system reliability and response time.
- Architected microservices leveraging DDD and event-driven patterns, supporting OAuth 2.0 and OpenID Connect for secure authentication.
- Spearheaded the development and launch of 'Student Map,' a personalized learning roadmap feature, which boosted user engagement by 20%.
- Automated content processing pipeline using AI and n8n, reducing onboarding time from 3-6 months to days.
- Mentored junior developers, fostering team growth and knowledge sharing.
Software Engineer
Compass UOL
03.2021 - 11.2022
- Engineered robust, scalable .NET backend systems to meet core business objectives, championing code quality through comprehensive reviews and test-driven development (TDD) within a Clean Architecture framework.
- Architected solutions using Domain-Driven Design (DDD) and Microservices, leveraging key design patterns (Strategy, Factory, Builder, Decorator, Command, Mediator, Singleton) to create flexible, maintainable, and scalable services.
- Led a new product from concept to market, driving its successful pilot and full-scale launch by architecting and deploying the core backend systems.
- Solved complex performance and security challenges to enhance system stability and reliability.
- Provided technical mentorship and fostered knowledge sharing to elevate overall team capabilities.
Software Engineer
Self-employed
Juiz de Fora e Região
02.2017 - 02.2021
- Led full-stack development of scalable web systems for the construction industry using ASP.NET, AngularJS, and SQL Server/.NET Core, supporting critical project workflows.
- Architected and optimized cloud infrastructure on DigitalOcean, achieving 99% uptime and reducing hosting costs by 60% through strategic scaling and automation.
- Mentored and led a development team in agile practices using the MEAN stack, improving code deployment frequency and reducing critical bugs by half.
- Spearheaded the end-to-end digitization of construction project management by replacing fragmented Excel/email workflows with a unified platform. This reduced proposal generation time from 4 days to 6 hours and improved budget accuracy.
- Integrated advanced reporting features that auto-generate client-ready materials, eliminating 50 hours of manual work per proposal and accelerating client engagement cycles.
- Automated key data processes and built managerial reporting tools, enabling data-driven decisions that improved project timeline adherence by 80% and identified cost-saving opportunities.
Full Stack Engineer
iPixel
Juiz de Fora e Região
07.2015 - 01.2017
- Full-stack web development and maintenance using ASP.NET MVC, Hibernate Framework, jQuery, and SQL Server.
- Managed code versions and collaboration via Git.
- Deployed and maintained applications on Amazon AWS for .NET environments.
- Developed managerial reports and implemented business logic for publicity agencies.
- Engaged in project teams to handle documentation, testing, and validation processes.
Full Stack Engineer
HQS Plus
02.2014 - 05.2015
- Full lifecycle development of .NET systems, including design, implementation, and maintenance.
- Implemented ORM mapping for efficient data layer abstraction and management.
- Leveraged modern .NET frameworks and libraries to build scalable and robust applications.
- Conducted requirements and specification surveys to align technical solutions with business needs.
- Designed database models and developed packages, procedures, and optimized queries.
- Built and enforced business logic rules to ensure application integrity and meet core objectives.
- Managed version control systems (e.g., Git) for collaborative code management and deployment.
- Served as an active member in project teams, contributing to planning, development, and delivery.
- Maintained clear communication with customers to gather feedback, present solutions, and manage expectations.
Intern
Prefeitura de Juiz de Fora
11.2013 - 01.2014
- Delivered responsive IT support, troubleshooting hardware, software, and application issues for end-users.
- Provided specialized assistance and attendance for Electronic Invoice services, including user training, system configuration, compliance verification, and issue resolution.
- Ensured the reliability and accuracy of e-invoicing platforms, facilitating seamless financial and legal operations for clients.
Scientific Initiation Scholarship
Embrapa Gado de Leite
03.2012 - 02.2013
- Conducted genetic evaluation analysis using advanced mathematical and statistical software (e.g., R, Python libraries).
- Developed and optimized scientific workflows to automate and standardize bioinformatics data processing pipelines.
- Created detailed charts and data visualizations to clearly interpret and present the results of genetic analyses.
- Authored and presented research papers at the company workshop, communicating complex findings to peers and stakeholders.
Full Stack Engineer
Cibio
Vila do Conde, Porto
09.2011 - 01.2012
- Developed a comprehensive animal management control system that reduced key processes from months to weeks by automating workflows.
- Conducted in-depth requirements and specification surveys to define project scope and user needs.
- Designed and implemented core business logic to automate and streamline animal management workflows.
- Architected and performed database modeling to support system functionality and data integrity.
- Managed full-cycle testing and validation to ensure system reliability and performance.
- Maintained direct communication with customers for feedback, demos, and iterative improvements.
Intern
Embrapa Gado de Leite
Embrapa Gado de Leite, Juiz de Fora, MG
06.2009 - 05.2011
- Supported the full software development lifecycle, including development, testing, and validation phases.
- Assisted in the creation and editing of technical reports and data visualizations (charts) for production analysis.
- Contributed to software management and maintenance tasks to ensure system stability and usability.
- Collaborated with the development team to implement features and resolve issues in a production-system environment.
Education
Master of Business Administration (MBA) - Project Management
Fundação Getulio Vargas
Juiz de Fora, Minas Gerais 01.2014 - 01.2016
Bachelor of Science - Information Systems
Faculdade Metodista Granbery
Juiz de Fora, Minas Gerais 01.2008 - 01.2013
Skills
- NET
- Nodejs
- MySQL
- AWS
- Domain-Driven Design
- Microservices
- Docker
- Test-Driven Development
- REST APIs
Languages
English (Native or Bilingual)
Spanish (Elementary)
Portuguese (Native or Bilingual)
Publications
- Intelligent Genomic Information Retrieval with Distributed System Resources
- Automação de representação de resultados de classificação linear para características de tipo
- Obtenção de metadados de sequências polimórficas em banco de dados remoto
- GisLeite: Plataforma livre para gestão e rastreabilidade de sistemas de produção de leite.
Timeline
Software Engineer
Conexia Educação
11.2022 - 12.2025
Software Engineer
Compass UOL
03.2021 - 11.2022
Software Engineer
Self-employed
02.2017 - 02.2021
Full Stack Engineer
iPixel
07.2015 - 01.2017
Full Stack Engineer
HQS Plus
02.2014 - 05.2015
Master of Business Administration (MBA) - Project Management
Fundação Getulio Vargas
01.2014 - 01.2016
Intern
Prefeitura de Juiz de Fora
11.2013 - 01.2014
Scientific Initiation Scholarship
Embrapa Gado de Leite
03.2012 - 02.2013
Full Stack Engineer
Cibio
09.2011 - 01.2012
Intern
Embrapa Gado de Leite
06.2009 - 05.2011
Bachelor of Science - Information Systems
Faculdade Metodista Granbery
01.2008 - 01.2013