Data Analytics Code
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What we expect
This will be an interview lasting approximately one hour, during which you will be expected to write code in Python and SQL throughout the conversation. Expect to be actively writing code throughout the session.
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📚 How to prepare – Code
Review the fundamentals
Feel free to write code without relying on autocomplete or documentation. Ensure a solid understanding of Python and SQL topics.
Practice problem-solving
Solve SQL and Python exercises on platforms like LeetCode, HackerRank, or DataLemur. Practice explaining your reasoning while coding. On the day of the interview, this will help guide the interviewer.
Plan before you code
Take a moment to understand the problem and outline your approach. Make a basic solution work before optimizing, and check your code with examples to identify problems early.
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Python
Variables and Data Types Data Structures Flow Control Functions → Basic data types Strings (text), integers (numbers without decimal places), floats (numbers with decimal places), and booleans (true/false).
→ Formatting strings and f-strings How to present texts in an organized way, including variables.
→ Type conversion: to transform one data type into another (e.g., number to text).→ Lists: How to create and access elements by index, “slice” parts of the list, and use methods such as append and insert.
→ Dictionaries How to create and access values by key, and how to use their methods.
→ Double Collections of items that cannot be modified after they are created.
→ List comprehensions concise way to create lists.→ Conditional statements The `if`, `elif` (else if), and `else` (else) statements are used to execute blocks of code based on conditions.
→ Loops`for` and `while` loops are used to repeat blocks of code.
→ Using break (to stop a loop) and continue (to skip an iteration of the loop).→ Define and call functions How to create your own reusable code blocks and run them.
→ Arguments and parameters How to pass information to functions (positional, by name, with default values).
→ Return values What a function can “return” as a result.
→ Scope and namespaces Where variables are visible and accessible in your code.
→ Lambda Functions: small anonymous functions (without a name). -
SQL
Basic Consultations Joins and Table Operations Advanced SQL Concepts →Declarações SELECT: Column selection and use of aliases (AS).
→ Data filtering WHERE clauses are used to specify conditions.
→Sort results ORDER BY to sort (ascending/descending).
→ Data aggregation functions such as COUNT, SUM, AVG, MIN, and MAX.
→ Data grouping GROUP BY and HAVING are used to filter groups.→ Types of JOIN: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, CROSS JOIN para combinar tabelas.
→ SELF JOIN Compare rows within the same table.
→ Set operations UNION and UNION ALL are used to combine query results.
→ Subqueries Nested queries (with a single value or multiple values).→Common Table Expressions (CTEs) Named and temporary queries for organizing complex code.
→Window functions Window functions (RANK, ROW_NUMBER, PARTITION BY) for calculations on groups of related rows.
→ CASE statements Conditional logic within queries.
Working with NULL values How to deal with missing data.
String manipulation LIKE and wildcards to search for patterns. -
📌 Checklist – Code
Want to make sure you haven’t forgotten anything? We’ll help you with this handy checklist to review the key points:
✅ I am confident in writing code in Python and SQL without autocomplete or documentation.
✅ I practiced problem-solving on platforms like LeetCode or HackerRank.
✅ I can explain my reasoning while I’m coding.
✅ I can plan my approach before I start coding.
✅I know how to make a basic solution work and then optimize it.
✅ I have studied and am familiar with the Python and SQL concepts described in the guide.
Business Case
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What we expect
Prepare to discuss past projects from your career and a real business problem that we will present. Clear reasoning and business acumen are more important than quick answers.
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How to prepare – Business Case
Previous projects
Prepare to discuss your past projects and conduct data analysis to solve a real business problem during the session.
Structured analysis
You will be asked to perform a structured analysis of a real-world problem. Describe how you would approach the problem, connect…insightsmake business decisions and use advanced analytics tools.
As highlighted
Before diving into the answers, take a moment to dissect the problem, clarify the objectives, and organize your thoughts. Show your reasoning, ask questions, consider the advantages and disadvantages (trade-offs and communicate clearly.
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📌 Checklist – Business Case
Want to make sure you haven’t forgotten anything? We’ll help you with this handy checklist to review the key points:
✅ I have previous projects from my career ready to discuss in detail.
✅ I can dissect a business problem, clarify the objectives, and organize my thoughts.
✅ I know how to connect insights to business decisions.
✅ I can explain my reasoning and ask questions to clarify the problem.
✅I am ready to discuss advantages and disadvantages (trade-offs) of different approaches.
Experiment Design
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What we expect
Prepare to discuss a real-world problem live and design an experiment from scratch. We expect you to be proficient in A/B testing methodologies.
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How to prepare: Experiment Design
Designing an experiment from scratch
We expect you to be able to design an experiment from scratch. This means you should have a strong understanding of how to systematically test a hypothesis and be able to implement an experiment from start to finish.
Statistical concepts
We suggest that you review the most relevant statistical concepts related to A/B testing, such as sample size, hypothesis testing, confidence intervals, p-values, statistical power, significance levels, and others.
Interpretation of results
Practice analyzing trade-offs, defining metrics, understanding limitations, and interpreting results in a business context.
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Checklist: Experiment Design
Want to make sure you haven’t forgotten anything? We’ll help you with this handy checklist to review the key points:
✅ I understand how to test a hypothesis systematically.
✅ I am familiar with A/B testing methodologies.
✅ I can design an experiment from scratch, from start to finish.
✅I can explain the statistical concepts of A/B testing.
✅ ANDI am prepared to discuss the advantages and disadvantages (trade-offs) of the decisions.
