
Gabriel de Freitas Piassetta
Verified Expert in Engineering
Python Developer
Florianópolis - State of Santa Catarina, Brazil
Toptal member since November 2, 2019
Gabriel is a senior software engineer and hands-on technical leader with 18 years of experience building production systems. He specializes in Python, FastAPI, PostgreSQL, distributed architectures, and applied AI, including LLM applications, RAG, agentic workflows, LangGraph, and evaluation systems. He excels at turning ambiguous problems into scalable, reliable solutions.
Portfolio
Experience
- Python - 20 years
- Linux - 18 years
- Web Development - 15 years
- Django - 8 years
- Flask - 8 years
- Django REST Framework - 8 years
- Clean Code - 5 years
- Clean Architecture - 5 years
Preferred Environment
Docker, Git, PyCharm, Ubuntu
The most amazing...
...Built AI infrastructure for a health platform that turns complex, fragmented medical data into reliable, traceable insights people can actually use.
Work Experience
Back-end Developer
The PepsiCo Foundation, Inc. - Food for Good
- Architected and implemented a scheduled shipments feature from data modeling to async task processing, enabling automated order creation and reducing manual operational work.
- Developed permission-based invoice editing, transactional order state management, and configurable inventory expiration rules, improving operational flexibility across the fulfillment pipeline.
- Designed and built a registration and address management system with security layers, approval workflows, and audit logging, delivering 15+ back-end API endpoints end-to-end.
Senior Software Engineer
Function Health
- Built and maintained production-grade backend services and AI-powered workflows using Python, FastAPI, PostgreSQL, GCP, LangGraph, and LLM-based systems.
- Reduced LLM context size by approximately 95% in a high-volume workflow, cutting payloads from roughly 720K tokens to 36K tokens through data pruning and context optimization.
- Designed and improved asynchronous, event-driven processing pipelines with retry strategies, concurrency controls, failure recovery, and observability for production workloads.
- Developed and maintained agentic AI workflows and evaluation pipelines, including the use of expert-reviewed clinical outputs as benchmarks for measuring model quality and reliability.
- Investigated and resolved complex production issues across APIs, distributed workers, PostgreSQL, Cloud Run, Pub/Sub, and AI infrastructure, improving system reliability and operational resilience.
Senior Python Developer
Sean Odwyer
- Rebuilt a completely non-functional legacy codebase from scratch after determining that the original system was technically unusable due to a lack of structure, documentation, and scalable design.
- Clarified business goals directly with the client, translated them into a clean technical architecture, and designed and delivered a fully working production system within the same timeline the client expected for only "fixing" the old code.
- Implemented a modern, serverless, event-driven workflow leveraging Google Cloud (Pub/Sub, Cloud Functions, Cloud Run), significantly improving scalability, reliability, and future maintainability.
Senior Software Engineer
Passport Fintech
- Developed and maintained secure API integrations with over banks using Python, enabling automated payments, balance checks, and transaction reconciliation for thousands of end users.
- Reduced payment processing errors by implementing robust validation and retry logic in bank API communication workflows.
- Led the refactor of legacy integration modules, improving test coverage and reducing incident response time related to banking failures.
Back-end Engineer
Pricemoov
- Developed integrations with leading eCommerce platforms.
- Planned and developed core features of the main application.
- Created several scripts to help onboard new customers.
Back-end Engineer
Loadsmart
- Developed a RESTful API to allow customers to submit loads they wanted to move.
- Proactively improved the CI flow, investigating and removing bottlenecks reducing the cost and time to run by more than 50%.
- Developed core features on the company's main platform.
Tech Leader
Conaz Soluções Tecnológicas
- Designed the data model to support the initial idea for the product.
- Created an API-first product (REST) using Flask to support front-end development.
- Developed from scratch, using Python, and clean-architecture concepts, the main product of the company. A market place where construction contractors can quote supplies.
- Constructed the whole infrastructure to support the operation.
Python Developer
Cloud Solucoes
- Developed the main product of the company: an SSO tool using Django and Django REST Framework.
- Created the project to start collecting metrics, as the engineers didn't have any information about the health of the systems.
- Constructed several integrations for the GSuite applications and the customers' software using pure Python, Flask, Django, and Go.
Python Developer
Gnovit Tecnologia
- Developed several integrations with Python and Asterisk PBX.
- Worked on level two customer support, which needed skills with Linux and low-level architecture.
- Designed and built the company’s core product and backend architecture using Python, Django, PostgreSQL, and cloud-native services, integrating multiple third-party APIs and internal systems to support scalable, production-grade workflows.
Experience
Access Control
Itinera
http://itinera.ccPermitFlow
Education
Bachelor's Degree in Information Systems
Universidade Federal de Santa Catarina - Florianópolis, Brazil
Skills
Libraries/APIs
REST APIs, Pydantic, OpenAI API, SQLAlchemy, WhatsApp API
Tools
ChatGPT, Claude, Claude Code, Observability Tools, PyCharm, Git, Celery
Languages
Python, Go, HTML
Frameworks
Flask, LangGraph, gRPC, Django, Django REST Framework
Paradigms
Clean Code, Clean Architecture, Event-driven Programming, Microservices
Platforms
Linux, Kubernetes, Google Cloud Platform (GCP), Docker, Amazon Web Services (AWS), Ubuntu, Langfuse
Storage
MySQL, PostgreSQL
Other
Web Development, FastAPI, Back-end, API Integration, APIs, LangChain, SaaS, Software as a Service (SaaS), Artificial Intelligence (AI), AI Automation, Software Architecture, Technical Leadership, Product Planning, Agentic AI, Architecture, Monitoring, Cloud, CI/CD Pipelines, Conversational AI, AI Agent Orchestration, AI Architecture, Workflow, AI Agents, OpenAI, Prompt Engineering, CTO, AI Product Management, Delivery Management, Fractional CTO, Large Language Models (LLMs), Retrieval-augmented Generation (RAG), AI Tools, Messaging, Bots, WhatsApp, WhatsApp Business, COO, Standard Operating Procedures Development
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