DataDriven.io is where data engineers practice for interviews.

Partners is how a small number of companies put a tool or an open role in front of them while they do it. We work with two to four partners per quarter, and we choose them carefully.

42k+
graded submissions / mo
68%
mid & senior IC
5.2
median yrs DE experience
38%
at venture-funded scaleups

Figures drawn from on-platform behavior and email-domain enrichment. Refreshed each quarter.

Audience composition

Who you reach.

Every active member has executed graded SQL, Python, or Spark on the platform. The numbers below are timestamps and submissions, not self-reported titles. Pick an attribute to see the breakdown.

Senior IC (5 to 10 yrs)41%
Mid IC (3 to 5 yrs)27%
Staff & Principal (10+ yrs)12%
Lateral from SWE or analytics14%
Early career6%
SQL (windowing, CTEs)94%
Python (transforms, pipelines)81%
PySpark or Spark SQL58%
Data modeling, dimensional49%
Pipeline or system design37%
Streaming (Kafka, Flink)22%
United States54%
United Kingdom & EU19%
Canada11%
India & SE Asia9%
Australia, NZ, other7%
Series B to D, data & AI28%
Enterprise & non-tech20%
Late-stage product cos17%
FAANG & equivalent14%
Fintech & quant12%
Between roles, in-market9%
In their words

A few of the engineers who practice here.

Anonymized while we build a public roster. Each is a verified, active member who agreed to be quoted.

The SQL drills caught a window-function gap I'd been working around for two years. Two weeks later it came up in a Stripe loop.

Senior Data Engineer
Series C fintech, NYC

I came in for a Databricks interview and stayed for the Spark optimization problems. Most prep sites stop at SELECT. This one keeps going.

Staff Engineer, Data Platform
Late-stage product co, SF Bay Area

Switched from analytics engineer to data engineer last year. The pipeline-design questions on here read like the ones a friend at Netflix had described.

Mid IC, Analytics → Data Eng
Series B AI tooling, remote
Become a partner

If your product is genuinely interesting to a data engineer, we would like to hear about it.

There are two ways to work with us. Reach is for developer-marketing teams running sponsored challenges or brand placements. Hire is for recruiting and TA teams running featured job listings. Tell us what you have in mind and we will scope it.