Solutions
Problems I've dealt with and how I approach them: what makes them hard, what the options are and which one I chose. If you're facing something similar, I'm happy to help.
Migrating data without stopping the system
from work
Moving a large amount of data to a new database schema while the system has to keep running.
Python, Oracle, ETL, incremental loading
Created: February 2026
Sensitive data anonymisation on Airflow
from work
A pipeline that takes raw files containing personal data, cleans them, anonymises them and checks them before anyone starts working with them.
Python, Apache Airflow, AWS S3, Pandas, Docker, GitLab CI/CD, pytest
Created: May 2025
Multitenancy in Django: keeping clients apart in one application
recruitment task
One application, many clients, and none of them may see another's data.
Python, Django, django-tenants, PostgreSQL
Created: September 2023
From CRUD to live editing: handling concurrent changes
from work
What to do when several people change the same record at once.
Python, Django, PostgreSQL
Created: June 2023
One column, a week of work: migrating a huge table in Django
from work
A naively simple migration on a table whose rows nobody counted any more ended up as a week of work and four migrations instead of one.
Python, Django, PostgreSQL
Created: May 2018
Search with autocomplete on Elasticsearch
from work
Suggestions after two letters, tolerant of typos and missing Polish characters.
Python, Elasticsearch
Created: April 2015