Lucas – Python, React, AWS, experts in Lemon.io

Lucas

From Brazil (UTC-3)flag

Full-stack Web Developer|Senior

Lucas – Python, React, AWS

Lucas is a Senior Full-Stack Engineer with 9+ years of experience building production-grade backend systems and React frontends for US startups. His core stack is Python (Django, FastAPI, Celery, LangChain) plus React/TypeScript, deployed on AWS with Terraform and Docker. He has solid experience across distributed systems, AI-powered backend integrations (LangChain, Anthropic API, MCP), and fintech/healthtech domains. Comfortable working directly with CTOs and product stakeholders, making architectural decisions, and owning delivery end-to-end.

10 years of commercial experience in
AI
Fintech
Healthcare
Marketing
Supply chain
Enterprise software
SaaS
Main technologies
Python
8 years
React
6 years
AWS
6 years
Typescript
6 years
AI-assisted coding
1.5 years
Additional skills
AI agent development
PostgreSQL
LangChain
Django
Docker
Redis
Celery
Terraform
GCP
FastAPI
Flask
GraphQL
Node.js
MongoDB
JavaScript
jQuery
MySQL
Java
React Native
Direct hire
Possible
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Experience Highlights

Senior Full-Stack Engineer
Mar 2025 - Ongoing1 year 3 months
Project Overview

Backend platform for AI-driven expert sourcing and lead scoring, built on a Python/Django monorepo with React frontends and AWS infrastructure. Core features include LLM-powered willingness scoring, deduplication logic, and similar-profile discovery, supporting multiple internal applications across a shared component library.

Responsibilities:
  • Built and maintained multiple Django and Celery backend services in a Python monorepo for dashboard reporting and AI-driven lead sourcing.
  • Designed paginated REST APIs with Django Ninja and Pydantic request/response schemas; built Django admin layers for internal tooling.
  • Integrated Anthropic and LangChain into production backend services for AI-assisted candidate sourcing, lead scoring, willingness scoring, deduplication, and similar-profile discovery.
  • Scaffolded a React/TypeScript monorepo frontend and created a shared component library consumed by multiple applications.
  • Implemented end-to-end authentication with Keycloak OIDC — token validation, protected routes, cross-subdomain sessions, and magic-link login.
  • Delivered AWS infrastructure on ECS Fargate via Terraform — wrote CI/CD pipelines and production Dockerfiles for backend and frontend deployments.
  • Added Sentry monitoring and API key authentication to shared Django libraries.
Project Tech stack:
Python
Django
Celery
Pydantic
Typescript
React
AWS
Terraform
Docker
LangChain
PostgreSQL
Redis
Sentry
CI
CD
Senior Full-Stack Engineer
Aug 2024 - Jan 20255 months
Project Overview

Health-tracking platform for at-home diagnostic test kits, enabling users to register kits, complete lifestyle questionnaires, and monitor their results. Includes a back-office management system for kit logistics and fulfillment operations.

Responsibilities:
  • Built backend services with Python and FastAPI for kit registration flows and questionnaire logic.
  • Developed React-based frontend for user-facing kit tracking and health data visualization.
  • Deployed services on AWS and GCP infrastructure with Docker.
  • Participated in code review and sprint planning.
Project Tech stack:
Python
FastAPI
React
AWS
GCP
Docker
Senior Back-End Engineer
Apr 2024 - Jul 20243 months
Project Overview

Manufacturing management platform providing a unified interface for engineering and procurement teams to collaborate on PCB design revisions and manage production scaling from prototype to high-volume runs, eliminating the need to switch vendors.

Responsibilities:
  • Contributed to Python microservices backend using FastAPI and Flask.
  • Deployed and managed services on AWS using Docker.
  • Participated in code review and sprint ceremonies.
Project Tech stack:
Python
Docker
FastAPI
Flask
AWS
Microservices
Senior Full-Stack Engineer
Oct 2022 - May 20241 year 6 months
Project Overview

Health and wellness platform enabling users to register at-home test kits and track their health goals through a gamified experience, with cross-platform mobile and web applications, goal-setting flows, and personalized health data insights.

Responsibilities:
  • Implemented a GraphQL-based backend architecture backed by MongoDB Atlas for data storage.
  • Built a Python API layer using Flask and FastAPI with PostgreSQL as the primary relational database.
  • Developed cross-platform mobile applications (React Native) alongside the web React frontend.
  • Applied Domain-Driven Design principles for maintainable service boundaries and cohesive data models.
  • Integrated Salesforce for CRM and business operations workflows.
  • Groomed backlog and planned sprints; participated in code review across the team.
Project Tech stack:
Node.js
GraphQL
React
GCP
Typescript
Docker
Senior Back-End Engineer
Aug 2021 - Jun 20231 year 9 months
Project Overview

Credit-building platform for US consumers, providing financial tools to establish and improve credit history. The system manages the full credit product lifecycle, user financial data, and integrations with CRM and third-party financial services.

Responsibilities:
  • Integrated core microservices with the Salesforce platform to support CRM-driven financial operations and customer data management.
  • Built and maintained backend API services using Python, Flask, and FastAPI with PostgreSQL as the primary database.
  • Applied Domain-Driven Design principles to enforce clear service boundaries and maintain a cohesive data architecture.
  • Contributed to sprint planning and backlog grooming.
Project Tech stack:
Python
Flask
FastAPI
PostgreSQL
AWS
Docker
DDD
Salesforce
Senior Full-Stack Engineer
Jul 2019 - Aug 20212 years 1 month
Project Overview

Core platform supporting a suite of digital content marketing products — including accounts management, subscription workflows, and financial operations — built on a microservices architecture with dedicated databases per service.

Responsibilities:
  • Contributed to centralizing shared data across the full product suite through a microservices-based architecture.
  • Implemented per-service isolated databases to enforce service boundaries and reduce coupling.
  • Built features using Node.js, TypeScript, and React across backend services and frontend applications.
  • Used AWS for scalable, reliable infrastructure; managed multi-service deployments with Docker.
Project Tech stack:
Node.js
Typescript
React
PostgreSQL
MongoDB
AWS
Docker
Microservices

Education

2026
Applied AI Software Engineering
Postgraduate
2017
Information Systems
Bachelor's

Languages

Portuguese
Advanced
English
Advanced

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