Developer Interview Questions

What are the different wait mechanisms in Selenium (Implicit, Explicit, Fluent Wait), and when should each be used? Explain the downsides of Thread.sleep() and how WebDriverWait improves reliability.

How do you handle dynamic elements or changing locators in Selenium automation? Discuss strategies like relative locators, XPath axes, CSS attribute wildcards, and Page Object Model to insulate tests from DOM changes.

What differences do you see between Selenium and Playwright in automation testing? Cover architecture, browser support, speed, built-in waiting mechanisms, and cross-language support.

When two developers push changes to the same file in Git simultaneously, how would you resolve the merge conflict? Walk through: pulling latest, identifying conflict markers (<<<, ===, >>>), choosing which changes to keep, testing after resolution, and committing the merge.

If a team currently using Selenium plans to migrate to Playwright, how would you help them adopt the new framework? Cover project structure, locator migration, parallel execution setup, and CI integration.

Explain async/await in JavaScript. How does it differ from Promise chaining? Write a function that fetches data from three APIs in parallel (Promise.all) and one after another (sequential await). When would you choose each?

How can you retrieve all the options available in a dropdown using Selenium? Explain the Select class, how to handle both static and dynamic dropdowns, and edge cases like dropdowns built with div/ul instead of the native select element.

Have you worked with CI/CD pipelines, and how were they used in your project? Describe the tools used (Jenkins, GitHub Actions, GitLab CI), the stages in your pipeline, how tests were triggered, and how deployments were automated.

Write a query to find, for each department, the employee with the second-highest salary, using window functions instead of a correlated subquery.

How does adding + "" help convert a char value into a String in Java? Explain Java's string concatenation rules, why char + "" produces a String while char + char produces an int, and alternative approaches like String.valueOf(char) or Character.toString(char).

Explain the difference between INNER JOIN, LEFT JOIN, and FULL OUTER JOIN with a simple example of Orders and Customers tables.

What is the purpose of the indexOf() method and how can it be used when removing duplicate characters from a string in Java? Walk through an O(n) solution using a LinkedHashSet or boolean array.