D8LooP
Build my plan

D8LooP · How it works

How to use D8Loop, from first visit to offer.

Four moves: get a plan, learn the ground, practise in the studios, rehearse the interview. Here is where each one lives, and what it costs.

9 knowledge bases483 reviewed scenarios1648 answered questions3 guided tours

01

Start with a plan

The dashboard asks two questions: your level, and your interview date. You get a day-by-day plan. It stays on your device until you sign in, then it follows you.

  • 0–2 yearsEarly career
  • 2–4 yearsMid level
  • 4–8 yearsSenior
  • 8+ yearsStaff
Build my planTwo questions, no accountBrowse the 18 staged plans3 groups: foundation, hands-on, interviewingExplore by reasonPlans, modules, topics and chapters, for someone not ready to pick

02

Learn the ground

9 knowledge bases. Every chapter is free, with no account. Read the chapter your plan points at, or go cover to cover.

03

Practise in the studios

Five studios, 483 scenarios. You make a real call, the review tells you what it found, and a question asks you to defend it. The first two scenarios of every studio are free, with no account.

  1. 01DecideMake the real calls: the grain, the write mode, which line starts a Spark job.
  2. 02CheckSee what the review or Spark itself says about your call, with the evidence.
  3. 03DefendExplain it out loud, the way the follow-up question will ask you to.

Not sure yet? Take a five-minute tour first.

One tour per studio, on the studio's first scenario, replayed from real work. No sign-up to watch.

  1. Studio 01 · Data PipelineDaily orders ETLBatch or streaming, what the quality gate does, how the sink writes — then the checks read every setting on your DAG.Draw the DAGConfigure every nodeGet it reviewedTake the tour
  2. Studio 02 · Data ModellingMarketplace core entitiesWhere an order’s lines live, what stops a double charge, what an order remembers — then your ERD is built, seeded and queried.Set grain and keysSeed and query itDefend the designTake the tour
  3. Studio 03 · Spark PlaygroundTwo counts, two scansCall which cells start a Spark job, run them, then read the job DAG, the plan and the task times Spark recorded.Predict the jobsRead the DAG and planExplain the shuffleTake the tour

04

Rehearse the interview

When the plan says you are ready: answer the questions out loud, read how real rounds went, and look at who is hiring.

1648 answered questions15 subjects. Each one carries the answer, the answer that gets you rejected, and the follow-up.50 company write-upsHow the interview ran, round by round, and what got people rejected.The 6 interview roundsWhat each round scores, and which plan prepares you for it.Live data engineering jobs220 companies, refreshed every 6 hours. Apply when the plan says you are ready.Sit a live interviewOne code, 14 modules, timed, graded on what actually ran. Or run one for someone else.

05

Track it, and what it costs

The dashboard shows today's step and how far you are. Your profile keeps every run. Here is what is free and what is not.

  1. $0Free, no accountEvery chapter of every knowledge base. The first two scenarios of each studio. A plan, kept on this device.
  2. $0Free accountEvery Foundations and Intermediate scenario. Your plan and progress follow you. A preview of the interview lab.
  3. $19Pro, a month. Or $149 a year.Advanced scenarios, the design review and the defend step, every run kept, and the Spark playground on a real machine.
Open the dashboardToday's step, and how far you areSee the pricingThe canvas is free. Review and defend is what you pay for.

06

Or skip all this, start building

Design a daily orders pipelineFree, no accountModel a marketplaceFree, no accountRun real PySparkBrowse 111 Spark scenarios