Exercise 1.1 β Map a Prior ETL Project to a Modern Stack
A short reflection + translation exercise. If you've worked on a data-ingest pipeline earlier in your career, you've done DE β you just called it something else. This exercise pulls that forward so you can tell the interview story with confidence.
Time: 20β30 minutes. Output: a paragraph you can actually use in an interview: "Yes, I've built data pipelines. A prior projectβ¦"
The prompt
Pick a past project you worked on that moved data from a source (files, database, API) into a database or warehouse β or imagine a canonical one if no past project fits. Then re-tell it using the modern DE stack. Fill in each box below. Notes auto-save to your notepad tagged module-01-orientation.
Step 1 β Extract
Then (classic approach)
Seed: Scheduled script runs on a cadence. SFTP/HTTP/API pull to pick up new data. Validates file arrived, checksums, kicks off next step.
Now (Snowflake + AWS, modern)
Step 2 β Load (raw)
Then
Seed: A bulk-load command into a staging table. Row counts verified against source's "expected rows" header.
Now
Step 3 β Transform
Then
Seed: SQL scripts in a specific run order. Business rules in SQL, some in Python. Manual QA on the output before publishing.
Now
Step 4 β Orchestration
Then
Seed: Cron. Success/failure emails. Bash glue.
Now
Step 5 β Ops / observability
Then
Seed: Runbook, pager, log files in /var/log.
Now
Step 6 β Version control & deploy
Then
Seed: Scripts in SVN or Git, manual deploy.
Now
Interview talking-point
Now, in 3β4 sentences, tell the story of that project as if the interviewer asked "Do you have experience building ELT pipelines?" β using the modern language.