The Data Foundry

Built by Data with Pranjal

The Data Foundry

Practice Data Engineering like real work.

Practice real data engineering scenarios, get feedback, and build interview-ready judgment across SQL, PySpark, Airflow, AWS, and production debugging.

Built by Data with Pranjal

Product preview

Practice loop
1

Broken problem

Pipeline rerun doubled revenue

2

User attempt

Write the fix

3

Feedback

Check the answer

4

Model answer

Learn the interview framing

132+

Practice scenarios

SQL, pipelines, incidents, and interview cases

SQL + PySpark

Hands-on labs

Browser-first practice without backend-heavy infra

Production

Debugging mindset

Broken logic, logs, trade-offs, and monitoring

Free

Starter labs

Begin with guided practice before upgrading

Why normal courses are not enough

Interviews test judgment, not only syntax.

Real data engineering work means debugging late data, broken joins, retries, schema drift, orchestration gaps, and dashboard mismatches. The Data Foundry turns those situations into daily practice instead of passive watching.

How it works

Step 1

Pick your goal

Tell us your stage, target, available time, and timeline.

Step 2

Solve a real scenario

Start with a free lab using realistic data and broken logic.

Step 3

Get feedback

Run checks and see what is correct, missing, or risky.

Step 4

Explain like an interview

Practice root cause, fix, trade-offs, and monitoring.

Step 5

Track progress

Use the dashboard to continue the next recommended lab.

Try before signup

Solve one free production SQL lab without creating an account.

Inspect sample data, submit a corrected query, compare actual versus expected output, and get feedback. Signup is only suggested after your first attempt.

Try free lab

Core Labs

A platform for practice, simulation, and job readiness.

Available

SQL Lab

Debug query logic, grain issues, NULL traps, CDC, rankings, and warehouse outputs.

Open lab->
Available

PySpark Lab

Practice performance, partitioning, UDF replacement, skew, and DataFrame reasoning.

Open lab->
Available

System Design Studio

Design data platforms, defend architecture trade-offs, and practice interview framing.

Open lab->
Available

Scenario Playground

Work through production-style incidents with broken logic, logs, data, hints, and feedback.

Open lab->

Who it is for

Freshers building job-ready confidence
Career switchers moving from analytics or software
Junior data engineers learning production thinking
Interview candidates who need scenario practice
Recently joined data engineers surviving the first 90 days

Free vs Premium

Free

Start with selected SQL and production scenarios, hints, validation, and progress tracking.

Premium

Unlock the full library, deeper debugging labs, model answers, follow-ups, and advanced system design practice.

See pricing

Broken Pipeline Lab

Practice real production failures, not PDF-style Q&A.

The new scenario lab includes MCQ diagnosis, broken SQL, PySpark fixes, log analysis, output mismatch debugging, hints, model answers, and interview-style evaluation.

See Scenario Library

Creator trust

Built by Pranjal, creator of Data with Pranjal.

Practical Data Engineering content focused on real interviews, production problems, and career-switcher friendly explanations.

Creator

Built by Pranjal

Creator of Data with Pranjal, focused on practical Data Engineering preparation.

YouTube proof

Content-led learning

Placeholder for channel stats, walkthroughs, and public learner proof.

Learners

Community proof

Placeholder for student wins, testimonials, and cohort outcomes.