Python Backend Developer – Batch Analytics & Scoring System (CSV / PostgreSQL)

I am looking for an experienced Python backend developer to implement a batch analytics and scoring system that processes large CSV datasets, applies deterministic scoring logic, stores historical results, and outputs structured CSV reports.

This is not a machine learning project and not a real-time system.
The scoring logic already exists and is finalized in a working Google Sheets prototype. The task is to port this logic into a scalable backend implementation.

What the system will do

Ingest large CSV files (≈500k users per run, plus reference datasets)

Apply predefined per-user and per-feature scoring logic

Store results and historical snapshots in PostgreSQL

Output clean CSV files with:

final scores

per-feature contributions

Allow inspection of individual users (e.g. retrieve per-feature contributions and past snapshots)

Technical requirements

Strong Python skills
Experience with pandas / numpy for large batch processing
PostgreSQL (schema design, bulk inserts, indexing)
Writing deterministic, well-structured, testable code
Comfortable handling large CSV files efficiently