A. Rosa Castillo, PhD
Verified Expert in Engineering
Data Scientist and Developer
Málaga, Spain
Toptal member since September 29, 2022
Rosa is a full-stack developer and data scientist with a PhD, solid research skills, and extensive software engineering experience. Combining the academy and industry approaches to data sciences, she can contribute to the whole data pipeline—from exploratory data analysis to prototyping and production. Rosa has also efficiently worked on projects across different countries using her professional English, Italian, German, and Spanish proficiency.
Portfolio
Experience
- Software Development - 13 years
- Requirements Analysis - 8 years
- Research - 7 years
- Data Science - 5 years
- Data Analysis - 5 years
- Python - 5 years
- Machine Learning - 5 years
- Docker - 3 years
Preferred Environment
Python, Machine Learning, Data Science, Cursor AI, Claude Code, AI Agents, Agentic Frameworks
The most amazing...
...solution I've pushed into production was an AI agent that reviews Web3 vulnerability reports, achieving 80% accuracy in classifying true/false reports.
Work Experience
AI Systems Architect & Security SME
Immunefi
- rchitected production-grade Agentic AI systems (LangGraph), optimizing the multi-step reasoning loops to maximize accuracy while minimizing computational overhead and energy intensity.
- Implemented a spam detector for security reports, achieving 70% accuracy in detection.
- Developed rigorous performance and sustainability metrics for LLM agents, establishing the empirical baseline for evaluating the 'Green AI' trade-offs of autonomous security workflows.
Talent Evaluator
Bijles Aan Huis B.V.
- Prepared technical interview with different technical exercises.
- Completed full interviews with several candidates for the role requested by the client.
- Created insightful reports about the candidate's performance on the interview.
Lead AI Researcher: Autonomous Agents
Valory.xyz
- Optimized autonomous agent frameworks (CrewAI) for blockchain data, focusing on inference efficiency and hardware-aware algorithm design to reduce the environmental footprint of real-time forecasting.
- Improved the current trading algorithm used for the blockchain agents.
- Benchmarked and integrated high-performance LLMs, evaluating model selection through the lens of carbon intensity vs. predictive power.
Python and R Library/Package Developer
National University of Singapore - Main
- Helped the research team—committed to building a high-quality analysis package—incorporate some best practices regarding software architecture, coding guidelines, and testing.
- Contributed to the improvements introduced in the documentation about the Python package, making the code more robust, reliable, scalable, and easier to maintain.
- Instructed the small team on the next steps and how to follow the best coding guidelines as part of the engagement.
Data Scientist
Fortris
- Collected Blockchain data and performed accounting algorithms on it, expanding my knowledge of Blockchain technology.
- Explored finance terminology and how to build meaningful reports for stakeholders.
- Started using Neo4j to implement graph analysis and represent data more efficiently than just applying plain relational database models.
Data Scientist
The Workshop
- Built more efficient SQL queries to deal with a huge data volume and created my first reports in Tableau.
- Created data pipelines using Kafka streaming and learned to use Docker for effective testing.
- Worked on my very first project in Spark to compute fraud detection metrics.
AI Engineer
Accenture
- Performed a deep customer service analysis based on ticketing data for various companies.
- Developed different NLP techniques as part of the data product offered to clients.
- Improved reporting practices by sharing visualization graphs with the clients.
R&D Engineer
Haag Streit AG
- Managed a team of two for three months while looking for a new project manager. I also wrote risk analysis for a project, conducted computer estimations, and handled employee performance reviews.
- Handled requirements engineering carefully, considering regulations and tracking needs in the healthcare sector. Became certified in software requirements engineering by the International Requirements Engineering Board.
- Worked on a refactoring project with a challenging new system's software design and architecture. I learned a lot about software patterns and algorithm optimizations.
Software Engineer
Annax Information Systems
- Worked on the system architecture, analysis, and design of software components using UML, Enterprise Architect, and other software engineering tools.
- Embedded code in a Linux-based device used in trains to manage train announcements.
- Coded with C++ and handled testing both in the lab and running trains.
Experience
Account Takeover Detection Model
I designed and developed a POC using the available web data to build a detection model for classifying web activity into different risk scores.
Player Forecasting Model
I designed and developed a SARIMA model that achieved high accuracy on the volume predictions and worked both during and after the COVID-19 period.
Game Recommender System
Ticket Similarity Application
VIP Customer Classifier
https://github.com/cyberosa/classifier_with_unbalanced_dsVulnerability Classifier AI Agent
Education
PhD in Computer Science
University of Malaga - Malaga, Spain
Certifications
Machine Learning Specialization
Coursera
Deep Learning Specialization
Coursera
Data Science Specialization
Coursera
Certified Professional for Requirements Engineering
International Requirements Engineering Board
Skills
Libraries/APIs
Pandas, TensorFlow, OpenMP
Tools
PyCharm, Slack, Git, Jira, Kafka Streams, Tableau, Confluence, Excel 2010, DataViz, Amazon Athena, Amazon QuickSight, Claude Code
Languages
Python, Java, UML, R, SQL, C++, Embedded C++
Paradigms
Parallel Programming, Requirements Analysis, ETL, API Architecture
Storage
Data Pipelines, MySQL, Elasticsearch, Neo4j
Frameworks
Spark, Flask, Agentic Frameworks, LangGraph
Platforms
Jupyter Notebook, Docker, Apache Kafka, Linux, Blockchain, Kubernetes, Amazon Web Services (AWS), CrewAI, Langfuse
Other
Machine Learning, Data Science, Software Development, Algorithms, Software, Technical Requirements, Research, Data Analysis, Programming, Analysis, Recommendation Systems, Forecasting, Fraud Prevention, Data Engineering, Data Reporting, Data Analytics, Data Modeling, Mathematics, Product Analytics, Artificial Intelligence (AI), Data Visualization, APIs, Artificial Intelligence (AI), Machine Learning, Deep Learning, User Requirements, System Requirements, Functional Requirements, Statistics, Data Products, Regression, Hyperparameters, Natural Language Processing (NLP), Real-time Data, QA Testing, Scripting, Clustering, Statistical Analysis, Statistical Modeling, Generative Adversarial Networks (GANs), Mathematical Analysis, Predictive Modeling, Risk Analysis, Generative Pre-trained Transformers (GPT), Stream Processing, Business Analysis, Time Series, Generative Artificial Intelligence (GenAI), Large Language Models (LLMs), Fraud Detection, Agentic AI, Retrieval-augmented Generation (RAG), HPCC Systems, Compilers, Business Requirements, Convolutional Neural Networks (CNNs), Deep Neural Networks (DNNs), Image Processing, Reporting, Logistic Regression, Bayesian Statistics, Computer Vision, Finance, Tax Accounting, Directed Acrylic Graphs (DAG), Dagster, Cryptocurrency, nbdev, Version Control, API Design, Base Blockchain, Hugging Face, Prompt Engineering, Technical Leadership, AI Agents, Security, Cursor AI
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