Tech interview concepts, explained
Short, focused articles on the concepts behind tech interview questions — the traps interviewers actually probe, with worked examples. See all topics we cover.
- GeneratorsEN
Generators: understanding the forgotten value of lazy evaluation
Explore how Python generators promote memory efficiency and the importance of iteration for their functionality.
- Power BIEN
Power BI exercises for data analyst interviews
Master Power BI with practical exercises that tackle common interview challenges and real-world scenarios.
- SQL InjectionEN
When to use SQL Injection prevention techniques, and when to refactor
Learn the critical decision points for SQL Injection prevention that affect security and development efficiency.
- Virtual DOMEN
When to use the Virtual DOM (and when not to)
Understand the benefits and pitfalls of the Virtual DOM for performance and development efficiency in React and similar frameworks.
- Automated TestingEN
When to use Automated Testing (and when not to)
Mastering automated testing involves knowing the right scenarios, pitfalls, and production realities that can make or break your deployment.
- ExcelEN
Excel test for job interviews: the formulas you will be asked
Master essential Excel formulas to excel in job interviews and real-life data analysis tasks.
- Pivot TablesEN
Pivot Tables exercises for data analyst interviews
Master pivot tables with practical exercises focusing on common pitfalls and interview scenarios for data analysts.
- VariablesEN
Variables — type coercion traps that confuse developers
Understanding variable behavior and type coercion can prevent common pitfalls in coding interviews and production.
- Tailwind cssEN
Tailwind CSS common mistakes: managing responsive designs effectively
Learn how to navigate common pitfalls in Tailwind CSS, especially with responsive designs and conditional class applications, to excel in interviews and on the job.
- Common Table ExpressionsEN
Common Table Expressions exercises for data analyst interviews
Mastering Common Table Expressions is crucial for clarity in SQL queries, especially for data analyst roles.
- DAXEN
DAX test for job interviews: avoiding common pitfalls in formulas
Master DAX for job interviews by learning key formulas and common mistakes to excel in your role as a data analyst.
- InteroperabilityEN
Interoperability: the silent killer of microservices architecture
Mastering interoperability is key to preventing communication breakdowns in microservices environments and ensuring seamless integration.
- Descriptive StatisticsEN
Descriptive Statistics interview practice: understanding averages and variability
Master the essentials of descriptive statistics with guided exercises and practical insights to excel in data analysis interviews.
- Business KPIsEN
Business KPIs exercises for data analyst interviews
Master critical KPI exercises to excel in data analyst interviews and on the job, improving your analytical skills for real-world data.
- AccessibilityEN
When to use Accessibility (and when not to)
Mastering accessibility in web development can greatly enhance user experience and SEO, but knowing when to prioritize it is crucial.
- HTML BasicsEN
HTML Basics: Common Interview Mistakes to Avoid
Master HTML basics to tackle common interview questions and real-world coding challenges effectively.
- SQL JoinsEN
SQL Joins test for job interviews: common pitfalls and best practices
Master SQL Joins to handle complex data queries effectively and avoid common interview pitfalls.
- OWASPEN
When to use OWASP: prioritizing vulnerabilities effectively
Learn how to strategically address OWASP vulnerabilities and prioritize remediation to effectively secure web applications.
- SQL Window FunctionsEN
SQL Window Functions test for job interviews: common mistakes to avoid
Master SQL window functions with practical exercises and avoid common pitfalls to excel in interviews and on the job.
- Password HashingEN
Password Hashing common mistakes: Choosing hashing algorithms
Understand password hashing pitfalls to avoid common mistakes during interviews and real-world applications.
- Data ModelingEN
Data Modeling exercises for data analyst interviews
Master data modeling with practical exercises to ace analyst interviews and enhance on-the-job performance.
- Data VisualizationEN
Data Visualization exercises for data analyst interviews
Mastering data visualization exercises is crucial for success in data analyst interviews and on-the-job tasks.
- JWTEN
JWT: Choosing Between HTTP-Only Cookies and Local Storage
Understand the trade-offs of storing JWTs in cookies vs. local storage to improve security and avoid common pitfalls in production.
- User InterfaceEN
User Interface: Designing for Engagement and Retention
Master crucial UI principles to enhance user engagement and drive retention in interviews and on the job.