browserstack Interview Patterns

Discussion about current and previous projects, work experience, and technology stack.

Implement four web services in the language of choice: startBrowser(), stopBrowser(), getLatestURL(), and deleteAllHistory(). The last two required understanding how browsers store user-specific data locally (e.g., Mozilla Firefox uses places.sqlite). JDBC Driver was to be used for extracting/deleting data from .sqlite files, and Selenium or third-party automation tools were prohibited.

Implement functionality similar to 'tail -f' to fetch the latest logs from a file and send them to all clients. Subtask 1: Implement tail -f programmatically without using the tail command directly. The solution should display only the last changed data when the file is saved, and avoid reading from line 0 to handle large files efficiently. Subtask 2: Use WebSockets to send the data to all clients.

Discussion about current and framework architecture, core Java, JSP-Servlets, JSF-Managed Beans, Oracle ADF, and database ORM. Questions about career experiences, conflicts with managers, learnings, and Java frameworks. One question was based on Map-Reduce Framework and its modification to run in a multi-clustered environment.

General discussion about the candidate's background, college experiences, preferences between startups and MNCs, strengths and weaknesses, reasons for not applying for GSoC, reasons for leaving the previous organization, and reasons for choosing BrowserStack.

Discussion about the candidate's journey, career goals, learnings from the current company, and preferences for the next job. The HR also asked about the most important thing in the candidate's career.

Online HackerEarth test with 3 questions for 2 hours, totaling 200 marks. Questions were of Easy/Medium difficulty.

Problem required implementing a log watching solution (similar to 'tail -f' command in UNIX). Tasks included: 1) Implementing a server-side program to monitor a log file and stream updates in real-time. 2) Creating a web-based client (accessible via http://localhost/log) that displays updates in real-time without page refresh. The client should show the last 10 lines upon initial load. Constraints included pushing updates in real-time, handling multiple clients, and avoiding retransmission of the entire file. Off-the-shelf libraries providing tail-like functionalities were not allowed.

Problem involved implementing a stateless web service to interact with Google Chrome and Mozilla Firefox browsers. The service supported endpoints for starting/stopping browsers, cleaning up browsing sessions, and retrieving the current active tab's URL. Constraints included not using Selenium WebDriver protocol and ensuring the service runs on the server's machine.

Technical round with the Engineering Manager. Topics included discussing favorite internship projects, personal projects, strengths/weaknesses, and solving problems like bringing all zeros to the start of an array in O(n) time and O(1) space. Also included a data structure design problem requiring O(1) query time and handling a 1TB file with limited RAM (8GB) for word occurrence counting.

Technical round with the Director of Engineering. Topics included projects, failed projects, HTTP vs HTTPS, HTTP error codes, User-Agent in HTTP headers, handling conflicts with managers, independent problem-solving, system deployment considerations, logging for monitoring, and database scaling.

HR Interview round.