Charles J

Junior Python Data Engineer

Aug 2024 - Nov 2024 • 3 mos

Designed and implemented end-to-end data pipelines in Python and SQL — covering raw ingestion, staging, transformation, and analytics layers across PostgreSQL databases. Built and scheduled Apache Airflow DAGs to automate recurring ETL jobs, replacing manual processes and improving data freshness for downstream consumers. Engineered a semantic job-matching pipeline using Python, LangChain, and pgvector — parsing CVs and vectorising content for similarity search across 2,400+ live listings. Implemented incremental loading patterns (upsert / ON CONFLICT DO UPDATE) and run logging to support efficient, restartable pipeline execution at scale. Delivered a RAG-powered knowledge base using PostgreSQL/pgvector and LangChain, achieving sub-3-second query latency under load in production testing.

Junior Python Developer

Feb 2024 - Nov 2024 • 9 mos

Built scalable Python backend services and data ingestion scripts for small business clients — automating data collection from APIs and CSV sources into PostgreSQL. Developed Django-based web applications with user authentication, role-based access, and data export functionality tailored to client reporting needs. Integrated LangChain and OpenAI APIs to add AI-powered features including document summarisation, semantic search, and automated content generation. Containerised applications with Docker and set up GitHub Actions CI/CD pipelines, enabling reliable and repeatable deployments across client environments. Maintained 80%+ test coverage using pytest; resolved bugs and performance bottlenecks identified through production monitoring and client feedback.