BrainRank
Data Analyst roadmap

Data Analyst roadmap: your 90-day plan

A 90-day plan to go from basics to interview-ready: SQL first, then analysis and dashboards, then a portfolio you can talk through.

Assumes 8-10 hours a week

How each step works

  1. Learn
  2. Check yourself
  3. Find weak areas
  4. Practise
  5. Check again

Steps marked BrainRank assessment link to a test or tool on BrainRank. Steps marked Self-check are exercises you do yourself. If a check shows a gap, practise and check again before moving on.

Days 1-30

Query and summarise data confidently

  1. Step 1SQL

    SQL fundamentals

    Goal: Write queries that filter, sort and aggregate a single table.

    Practise

    • Load a free sample sales dataset into a local database
    • Write queries using SELECT, WHERE, ORDER BY, GROUP BY and HAVING
    • Answer ten business questions such as 'top five products by revenue'

    Check yourself

    Self-check
    Ten-query self-check

    Without notes, write queries for ten new questions on the same table. Re-learn any concept you got wrong, then try ten more.

    Interview prep: Be able to explain the difference between WHERE and HAVING with an example.

  2. Step 2SQL joins

    Combining tables

    Goal: Join related tables correctly and avoid duplicated or missing rows.

    Practise

    • Practise INNER, LEFT and FULL joins on orders, customers and products
    • Find customers with no orders using a LEFT JOIN
    • Check row counts before and after every join

    Check yourself

    Self-check
    Join self-check

    For five questions, predict the row count before running the query. Wrong predictions show which join types to revisit.

    Interview prep: Draw how a LEFT JOIN works and explain when it creates duplicate rows.

  3. Step 3Excel

    Spreadsheet analysis

    Goal: Clean data and summarise it with lookups, pivot tables and charts.

    Practise

    • Clean a messy sheet: remove duplicates, fix text and dates
    • Use XLOOKUP or INDEX/MATCH to combine two sheets
    • Build a pivot table and a chart that answers one business question

    Check yourself

    Self-check
    Pivot table self-check

    Rebuild your analysis from the raw data in under 30 minutes without your notes.

    Interview prep: Prepare to describe how you would clean a dataset you have never seen before.

Days 31-60

Analyse trends and present them visually

  1. Step 4Window functions and CTEs

    Advanced SQL

    Goal: Calculate running totals, rankings and period-over-period changes.

    Practise

    • Rank products by revenue within each category
    • Calculate a running total and month-over-month growth
    • Rewrite one complex query using common table expressions

    Check yourself

    Self-check
    Window function self-check

    Solve five ranking and running-total questions without notes. Practise the patterns you missed, then retry with new questions.

    Interview prep: Explain ROW_NUMBER vs RANK vs DENSE_RANK with a tie example.

  2. Step 5Power BI or Tableau

    Dashboards

    Goal: Build an interactive dashboard that a manager can use without help.

    Practise

    • Connect your sales data to Power BI or Tableau
    • Build three visuals around one key metric and add filters
    • Ask someone else to use it and note where they get stuck

    Check yourself

    Self-check
    Five-minute walkthrough

    Present the dashboard in five minutes. If you can't state the key takeaway in one sentence, simplify it.

    Interview prep: Be ready to justify every chart choice on your dashboard.

  3. Step 6Numerical and logical reasoning

    The aptitude round

    Goal: Handle the timed aptitude test that many hiring processes start with.

    Practise

    • Take the aptitude assessment once to find your weak section
    • Practise that section in the question bank
    • Retake the assessment after two weeks and compare

    Check yourself

    BrainRank assessment
    BrainRank aptitude assessment

    20 questions in 20 minutes across logic, numbers, language and patterns. Note your weakest section.

    Start

    Interview prep: Practise mental arithmetic for percentages and ratios; analyst screens often include them.

Days 61-90

Build a portfolio and get interview-ready

  1. Step 7Analysis workflow

    End-to-end project

    Goal: Take a business question from raw data to a recommendation.

    Practise

    • Pick a public dataset and write the business question first
    • Clean, analyse and visualise the data
    • Write a one-page summary with a clear recommendation

    Check yourself

    Self-check
    Peer review

    Ask someone to read only your summary. If they can't tell what you recommend and why, rewrite it.

    Interview prep: Prepare a three-minute walkthrough: question, data, method, finding, recommendation.

  2. Step 8Storytelling with data

    Communicating insights

    Goal: Explain findings clearly to non-technical people.

    Practise

    • Turn your project into five slides
    • Practise explaining one chart without jargon
    • Record yourself and cut anything that does not support the main point

    Check yourself

    Self-check
    One-sentence test

    State each slide's message in one sentence. Slides that need two sentences need simplifying.

    Interview prep: Prepare an answer to 'Tell me about a time your analysis changed a decision.'

  3. Step 9Interview practice

    Interview readiness

    Goal: Go into interviews with practised answers and a resume that passes screening.

    Practise

    • Score your resume and fix the top suggestions
    • Read the interview guides for companies you are applying to
    • Do a timed mock: three SQL questions and one case question

    Check yourself

    BrainRank assessment
    BrainRank resume score

    Check ATS readiness and keywords, update your resume, then re-score it.

    Start

    Interview prep: Review the data analyst interview topics on the career guide.

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