Real-hardware telemetry for a mushroom fruiting chamber: an ESP32-C6 publishes 7 environmental sensors over MQTT into a decoupled, containerized stack.
Live dashboard → grafana.lukapokrajac.com
- Normalized heterogeneous sensor topics into one canonical event schema.
- Decoupled ingestion from storage with a Kafka stage so the producer never blocks on the DB.
- Containerized Kafka (KRaft) + Grafana with an auto-provisioned PostgreSQL source for one-command setup.
- Custom PlatformIO/C++ firmware for an ESP32-CAM, converting RGB565 frames to JPEG in software.
Wear Index ETL Pipeline
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Fully automated hourly ETL that ingests live Open-Meteo weather data and computes a custom “feels-like” index, deployed to AWS.
Live demo → wear.lukapokrajac.com
- Custom index from rolling-window averages and wind-chill logic.
- Idempotent incremental loads with 3-hour overlap and PostgreSQL UPSERT — zero duplication.
- Orchestrated with hourly Airflow DAGs; auto-refreshed materialized views for instant querying.
- Two Docker Compose stacks on a shared network; one-command setup via Makefile.
- Production instance on AWS EC2 with persistent PostgreSQL on RDS.
Exploratory analysis of the Olist Brazilian e-commerce dataset, turning messy relational data into actionable business insight.
View notebook → ecomm.ipynb
- Merged and cleaned multiple relational tables with pandas; resolved missing values and inconsistent timestamps.
- Delivery-performance analysis comparing estimated vs. actual dates to find logistics bottlenecks.
- matplotlib visualizations of price distributions and delivery-delay patterns.