Saif Mahin

Python Developer

SupplyCopia • Full-time

Dec 2022 - Present • 3 yrs 7 mos

As a Python Developer at Supply Copia, I build scalable data pipelines, AI-powered document processing systems, and automation frameworks that handle large-scale unstructured data with high accuracy. What I've built and delivered: Document & Invoice Processing: Designed end-to-end invoice extraction pipelines processing 100K+ documents monthly, transforming unstructured PDFs into clean, structured datasets (Excel, CSV, Parquet). Built AI-assisted parsing using OpenAI APIs and LangChain to resolve field ambiguities and boost extraction accuracy. Created automated QA frameworks to catch mismatches in amounts, vendors, and invoice numbers at scale. AI & Intelligent Systems: Integrated embedding models and re-rankers (BGE) for schema mapping and intelligent column matching. Contributed to AI chatbot development, connecting LLMs with structured data and knowledge bases. Led automation initiatives using AWS Lambda, reducing manual effort and improving processing speed. Web Scraping & Automation: Engineered high-performance scraping systems with concurrency, retry logic, proxy rotation, and anti-bot strategies for large-scale data collection. Built and deployed REST APIs using FastAPI and Flask for internal tools and data workflows. Designed S3-based orchestration workflows for storing and processing structured outputs. Data Engineering & Analytics: Developed Snowflake-based data pipelines with monthly partitioned tables and consolidated reporting layers. Built data reconciliation systems using fuzzy matching (RapidFuzz), normalization, and rule-based + AI logic. Implemented parallel processing (ThreadPoolExecutor, batching, checkpointing) to handle thousands of vendors efficiently. I work closely with cross-functional teams to deliver reliable, production-ready solutions that drive data accuracy, automation, and business efficiency.