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Cristopher – Python, LLM, AWS, experts in Lemon.io

Cristopher

From Brazilflag

AI Engineer|Senior
Back-end Web Developer|Senior

Cristopher – Python, LLM, AWS

Senior Python & AI Engineer who led 4 engineers and delivered production LLM applications for startups, including a YC-backed company. As the sole AI systems developer, he took full ownership of end-to-end delivery from RAG implementations to production deployment on ECS/Fargate with CI/CD pipelines. Strong focus on shipping reliable AI solutions with evaluation datasets and runtime monitoring.

9 years of commercial experience in
AI
Machine learning
Project management
AI software
Chatbots
Customer support software
NLP software
Software development
Main technologies
Python
10 years
LLM
6 years
AWS
6 years
LangChain
1 year
OpenAI
3 years
RAG
4 years
Additional skills
AI
Vercel
Next.js
NLP
SQL
Terraform
Hugging Face
Airflow
Amazon RDS
Tensorflow
PostgreSQL
Claude LLM
ElasticSearch
Amazon S3
AWS SageMaker
ETL
PyTorch
Amazon ECS
Vue.js
AWS Lambda
Redshift
Amazon EC2
Vector Databases
AWS CloudFormation
Typescript
FastAPI
Cursor
ElastiCache
AI agent development
Redis
React
Django
Product management
Project management
Pinecone
Flask
Direct hire
Possible
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Experience Highlights

Senior AI/ML Engineer
Oct 2024 - Ongoing1 year 3 months
Project Overview

It's a YC-backed US startup that uses AI role-play, coaching, and real-world feedback to build confident, capable leaders.

Responsibilities:
  • Designed a reproducible LLM evaluation pipeline benchmarking outputs against a curated golden dataset.
  • Built an experimentation system to compare prompt versions, model variants, and tools using human feedback.
  • Architected the AI Coach agent with structured tool-calling, RAG, task scheduling, and recommendations.
  • Added observability for model decisions and tool execution to enhance debugging and monitoring.
  • Implemented a provider abstraction and fallback strategy to handle LLM API outages or degradation.
  • Developed performance monitoring metrics, including latency, TTFT, error rates, and outage detection.
Project Tech stack:
Vercel
PostgreSQL
Next.js
React
Typescript
Python
AWS Lambda
Redis
ElastiCache
Amazon EC2
Terraform
AWS CloudFormation
LLM
OpenAI
Claude LLM
Cursor
AI agent development
Tech Lead
Mar 2024 - Oct 20247 months
Project Overview

It's a platform that offers scalable language training programs for companies that want to accelerate business performance worldwide.

Responsibilities:
  • Led a team of four engineers to build the Content Transformation Center (CTC) for ingesting audio, video, and image data.
  • Revitalized the team by tightening the scope, clarifying the requirements, and centralizing discussions for a more focused workflow.
  • Drove implementation and refinement of a content processing pipeline covering tokenization, text extraction, word sense disambiguation, classification, and text generation.
  • Oversaw dictionary enhancement efforts, including manual curation, similarity-based merging, and LLM-driven definition rewrites.
Project Tech stack:
Python
AWS
AI
Project management
Product management
PostgreSQL
FastAPI
Django
Senior AI Engineer
Apr 2024 - Oct 20246 months
Project Overview

It's an online learning community with thousands of classes for creative people. This project focused on the pre-existing chatbot that would chat with users to provide support and redirect them to existing flows, such as elevating the discussion to a human or issuing an automatic refund.

Responsibilities:
  • Led migration of a 10,000+ LOC LLM-powered customer service chatbot from a discontinued VC-backed product, despite missing tests and deployment docs.
  • Completed the migration in 3 months, restoring production service and pushing the project toward full cut-over.
  • Implemented unit and integration tests to reach 85% coverage, greatly improving stability and reliability.
  • Refactored and modernized the codebase with contemporary Python practices (type hints, Pydantic, FastAPI) and clear deployment procedures.
  • Built a RAG system with Pinecone to ingest Skillshare HTML documentation and power question-answering.
Project Tech stack:
FastAPI
Flask
Pinecone
Redis
PostgreSQL
LangChain
Senior Software Engineer & Applied AI/ML Engineer
Aug 2021 - Mar 20242 years 7 months
Project Overview

It's a platform that offers scalable language training programs for companies that want to accelerate business performance worldwide.

Responsibilities:
  • Built and streamlined a new ML pipeline with AWS Sagemaker, improving data processing and deployment efficiency in line with MLOps best practices.
  • Led migration of data pipelines to Airflow from AWS Data Pipeline, boosting scalability and maintainability across SQL, Redshift, PostgreSQL, and Redis.
  • Developed an advanced recommendation system and generative text models for educational content, increasing personalization and user engagement.
  • Established a dynamic ML backend/API layer for model microservices and created an ML playground for experimentation.
  • Drove projects in semantic search, text classification, and audio classification within a small, agile team.
Project Tech stack:
Python
AI
Typescript
FastAPI
AWS
OpenAI
Claude LLM
AWS SageMaker
Airflow
Terraform
AWS CloudFormation
AWS Lambda
PostgreSQL
ElasticSearch
Vue.js
SQL
Redshift
Amazon RDS
Amazon ECS
Amazon EC2
Amazon S3
Tensorflow
PyTorch
Hugging Face
NLP
ETL
Vector Databases

Education

2018
Computer Engineering
Bachelor
2020
Computational Modeling of Knoweldge
Master Degree
2016
Computer Engineering
Exchange Student

Languages

English
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