01
Data Pipeline Design
Loaded predictive-maintenance multimodal data into ADLS Gen2 and designed preprocessing based on a Medallion Architecture.
DATA ENGINEERING · AI
Industrial Predictive
Maintenance Pipeline
PERIOD
2025.12
TEAM
Microsoft Data School · 5 Members
ROLE
Data Pipeline · Model Training · Optimization
Databricks · Spark · Delta Lake · PyTorch · MLflow
01 — OVERVIEW
Facflexity is an industrial predictive maintenance project that processes large-scale multimodal sensor and thermal-image data to predict equipment conditions and support operational decision-making.
The project combined Databricks-based data processing, multimodal model training, and inference optimization while addressing bottlenecks caused by large-scale data.
02 — ARCHITECTURE
Predictive-maintenance data was stored in ADLS Gen2 and processed through a Medallion Architecture in Databricks before being used for model training and inference.
ADLS Gen2
Raw Data Storage
Databricks
Data Processing
Bronze
Raw Ingestion
Silver
Preprocessing
Gold
Model-ready Data
LSTM + CNN
Multimodal Model
AutoML
LightGBM
Inference
Equipment State
03 — MY ROLE
01
Loaded predictive-maintenance multimodal data into ADLS Gen2 and designed preprocessing based on a Medallion Architecture.
02
Trained and compared an LSTM + CNN multimodal model and an AutoML-based LightGBM model.
03
Resolved source-data loading delays, timeouts, and Driver OOM issues by redesigning file discovery and large-scale data loading.
04
Analyzed equipment-state transition intervals and redesigned the inference cycle to reduce unnecessary operational calls.
04 — DATA LOADING
CHALLENGE
Loading the original dataset required discovering large numbers of files and resolving their schemas. This increased preprocessing overhead and caused loading delays and timeout failures.
BEFORE
A broad file-search range and schema inference increased unnecessary loading overhead.
AFTER
Explicit schemas and Glob-based file filtering reduced unnecessary file discovery and stabilized loading.
SOLUTION
I constrained the file-search range with Glob patterns and defined schemas explicitly, removing unnecessary discovery work during ingestion.
05 — DRIVER OOM
MEMORY BOTTLENECK
The thermal dataset contained approximately 19,200 features per row across roughly 90,000 records. Converting the distributed Spark dataset into Pandas concentrated the data in Driver memory and caused OOM failures during model training.
BEFORE
Distributed Data
Collect to Driver
Full Dataset
Training Failure
AFTER
Distributed Data
by device_id
Subset Loading
Model Training
gc · Cache Clearing
Sequential Processing
SOLUTION
Instead of collecting the full distributed dataset into Driver memory, I filtered data by device_id, loaded each subset sequentially, trained the model chunk by chunk, and released memory before loading the next subset.
RESULT
The redesigned loading strategy eliminated the Driver OOM bottleneck and enabled stable end-to-end PyTorch model training on the large-scale dataset.
06 — INFERENCE OPTIMIZATION
Rather than keeping the original 30-second inference interval fixed, I analyzed equipment-state transition intervals and redesigned the inference cycle to 90 seconds.
INFERENCE CYCLE
30s → 90s
Cycle redesigned based on equipment-state transition intervals.
ESTIMATED MONTHLY CALLS
≈ 67% ↓
Estimated reduction in the number of monthly inference calls.
ESTIMATED INFERENCE TIME
323h → 108h
Calculated reduction in total monthly inference time.
These figures were calculated from the redesigned inference schedule. They represent estimated operational impact rather than long-term production measurements.
07 — RESULT
01
Reduced loading bottlenecks through explicit schemas and constrained file discovery.
02
Resolved Driver OOM through device-based sequential chunk loading and memory management.
03
Redesigned inference scheduling and quantified the estimated reduction in monthly compute workload.
08 — WHAT I LEARNED
Understanding the data can change the entire system design.
This project showed me that analyzing data volume, distribution, and equipment-state patterns can reveal optimization opportunities beyond model performance. Data-loading strategy and inference design directly affect system stability and operational efficiency.
Facflexity · 2025