Hi, I'm Sebastian
Backend Developer & AI Integration Specialist
Experienced Python Developer specializing in backend systems, AI integration, and scalable web solutions. Currently exploring the frontend universe with React and Next.js.
About Me
Get to know me better
Backend & AI engineer with 3+ years building production LLM systems: multi-tenant conversational agents, RAG pipelines, and async infrastructure. My journey in tech started at 8, exploring the internet and hacking, and led me to complete a degree in software engineering.
Hands-on with AI agents, AI-assisted coding, and n8n workflow automation, on top of a full-stack range that spans Python, React/Next.js, Flutter, React Native, and Laravel/PHP. I ship across web, mobile, and backend — from indie apps to client platforms.
Software Engineering
University of Colima • Jun 2024
Professional Experience
My journey in the tech industry
Full-time
Architect and lead developer for a custom Retrieval-Augmented Generation (RAG) system and backend services.
Key Achievements
- Orchestrated 5 OpenAI APIs in a unified state-machine (Response API, Assistants API, GPT-4o, Whisper, TTS) for a WhatsApp emotional-support agent
- Led Django-to-FastAPI migration, cutting server load 50% via Redis caching and async Celery
- Designed RAG architecture with semantic search using pgvector for multi-tenant sales assistants
- Built message processing with Celery and Redis for AI assistants
- Implemented Azure Functions for serverless invoice processing
- Migrated legacy SQL to SQLAlchemy + Alembic with versioning
- Developed REST APIs for auth, notifications and Azure integrations
Technologies Used
Contract
Re-engineered UX for flight seat reservation platform, improving onboarding and dashboards; implemented preference algorithms and tests.
Key Achievements
- Redesigned landing, onboarding and dashboard flows
- Implemented user seat preference algorithms
- Added end-to-end tests
Technologies Used
Contract
Trained and refined AI models through real coding challenges and prompt engineering; ensured correctness of AI-generated code.
Key Achievements
- Designed complex prompts to improve code generation
- Debugged and fixed functional issues in AI outputs
Technologies Used
Full-time
Developed Flutter apps with reusable widgets; integrated PDF generation with Python and GraphQL services.
Key Achievements
- Built reusable UI components for consistent UX
- Integrated Python/GraphQL PDF generators
Technologies Used
Skills & Technologies
Technologies I work with
Certifications
EnglishScore Core Skills (CEFR B1)
British Council
Nov 2023
DevOps Professional
IBM via Coursera
Jun 2024
Cloud Computing Specialist
IBM via Coursera
Jul 2024
Agile Development and Scrum Practitioner
IBM via Coursera
Jul 2024
Featured Projects
Here are some of my recent projects showcasing my skills in backend development, AI integration, and full-stack solutions.