Wallace Freitas
Professional Experience
MailerWeb
Hybrid
Mid-Level Software Engineer focused on AI
Jun/25 – Present- Developed scalable solutions in Python, applying best practices and architecture patterns to improve performance and maintainability.
- Migrated parts of a monolithic system into microservices, improving scalability and reducing deployment time.
- Designed and deployed a FastAPI-based containerized microservice (ECR/ECS), achieving 500% performance gain over the legacy system.
- Provisioned AWS infrastructure with Terraform, automatically generating up-to-date architecture diagrams.
- Implemented automated testing (unit, integration, and E2E) in GitLab pipelines to ensure continuous and reliable delivery.
- Set up observability with Sentry and UI automation testing using Playwright, enhancing system quality and visibility.
- Developed a conversational marketing AI using LangChain, Amazon Bedrock, and ChatGPT, adapting responses to user behavior.
KOGNITUS
Remote
Mid-Level Software Engineer
Jan/24 – May/25- Led architectural and system design decisions, applying SOLID principles and GoF design patterns for scalability and robustness.
- Developed and maintained desktop Python applications for processing and analyzing large-scale data (big data) unsuitable for web solutions.
- Established an automated testing culture with Pytest unit and integration tests, increasing reliability and reducing regressions.
- Performed extensive refactoring on legacy code, removing vulnerabilities and improving readability and maintainability.
- Built CI/CD pipelines in Bitbucket, automating build, test, and deployment processes, reducing delivery time and production issues.
- Led the team’s transition to Agile methodologies (Scrum and Kanban), facilitating ceremonies and fostering continuous improvement.
- Introduced remote collaboration tools like GatherTown, improving communication and productivity across distributed teams.
Transfero
On-site
Junior Software Engineer
Jan/22 – Dec/23- Created a full Web3-based financial management system from scratch, evolving from an internal tool to a commercial product.
- Developed microservices and REST APIs using Flask, FastAPI, and Django with a focus on scalability, performance, and service integration.
- Acted as DBA, handling modeling, administration, and optimization of PostgreSQL databases, including procedures and disaster recovery routines.
- Implemented serverless workflows with Azure Functions and AWS Lambda for automation, ETL, and web scraping.
- Managed cloud infrastructure (AWS/Azure) using Docker and Kubernetes for high availability and automated deployments.
- Set up CI/CD pipelines with GitHub Actions, integrating automated testing and infrastructure as code.
- Contributed to technical documentation, development standards, and Web3 integrations, including smart contracts and cryptocurrencies.
TIPLAN
On-site
IT Infrastructure Analyst
Apr/18 – Apr/20- Administered and monitored on-premise and cloud infrastructure environments, ensuring availability, performance, and security.
- Handled acquisition, setup, and maintenance of physical and virtual servers, managing the company’s computing assets.
- Administered Windows Server (2012/2016) and Linux systems, including AD, DHCP, DNS, IIS, Hyper-V, and Remote Desktop Services.
- Implemented backup and disaster recovery strategies to ensure data integrity and efficient restoration.
- Managed virtualization environments with Proxmox, KVM, LXC, Hyper-V, and Docker, optimizing resource usage and scalability.
- Configured and maintained firewalls (pfSense/OPNsense) and IPv4/IPv6 networks with VPNs, tunneling, and secure segmentation.
- Used Zabbix, Graylog, Grafana, Prometheus, and CloudWatch for observability, telemetry, and automation of critical operations.
Education
Pontifical Catholic University of Rio de Janeiro (PUC-Rio)
Aug 2016 – Jul 2023
Bachelor’s in Information Systems
Algorithms, Advanced Data Structures, Object-Oriented Programming, Software Engineering, Databases, Computer Networks, Operating Systems, Distributed and Cloud Computing, Information Security, Complexity and Computation Theory
Languages
- Portuguese: Native
- English: Intermediate – proficient in reading, writing, and conversation.
Skills
Development
- Languages: Python, Golang, Kotlin
- Databases: PostgreSQL, SQL Server, MySQL, Redis, MongoDB, DynamoDB
- Messaging: ServiceBus, Kafka, AWS SQS, AWS SNS
- CI/CD: GitHub Actions, GitLab Pipeline
- Architecture: Microservices, MVC, Hexagonal, Monolith
- Best Practices: Clean Code, SOLID, GoF, AAA, DDD, TDD, Event Storming, System Design, C4, ERD, UML, SAGA
- Resilience: Single Point of Failure, Circuit Breaker, Graceful Shutdown, Resilience Strategies
- Security: Vault, Encryption, OAuth 2.0, Public Key Authentication, Digital Certificates, OWASP Top 10
- Dev Tools: Docker, Insomnia/Postman, Git, GitHub, Bitbucket, Jira, Trello
Infrastructure
- Operating Systems: Windows Server (Administration), Linux (Administration), Active Directory
- Virtualization & Containers: Proxmox, QEMU/KVM, LXC, Hyper-V, Docker, Type 1 & Type 2 Virtualization
- Networking & Security: L1/L2 Networks, VPN (Site-to-Site & Client-to-Internet), Reverse Tunneling, Pi-hole/DNS, pfSense/OPNsense Firewalls
- Observability & Monitoring: Zabbix, Graylog, Grafana, Cacti, Prometheus, New Relic, Jaeger, Nagios, CloudWatch, Azure Monitor
- Cloud & Orchestration: AWS, Azure, Kubernetes (AKS & EKS)