Allen Digital | Machine Coding Interview | SDE-1 | Backend
Summary
I recently interviewed for an SDE-1 Backend role at Allen Digital, where I completed a machine coding challenge to design a Vaccination Booking System. I successfully implemented the core requirements within 100 minutes and was subsequently selected for the next round.
Full Experience
I had my first interview for an SDE-1 Backend position at Allen Digital, which was conducted by Barraiser, a third-party company. With around 10 months of experience, I was given 100 minutes within a 120-minute slot to design and code a complete Vaccination Booking System. The interview started and ended with 10 minutes for discussion. The interviewer presented specific requirements, for which I had to create APIs/functions. I successfully coded a working system incorporating all the mentioned requirements within the time limit. There was a bonus requirement, but due to time constraints, I couldn't implement it and was asked to upload the code and move to the discussion phase. The discussion primarily revolved around my approach and solution to the problem. I received a call from HR the next day informing me of my selection for the next round, which will be a DSA round.
Interview Questions (1)
I was tasked with designing an entire Vaccination Booking System within 100 minutes. The interview included an initial and final 10-minute discussion period, leaving me with 100 minutes to both conceptualize and code the system. The interviewer provided a specific set of requirements, for which I needed to create APIs/functions. The main requirements were:
- Add users and vaccination centers.
- Allow each vaccination center to have varying daily capacities, be located in different districts and states, and support modification/addition of daily capacity.
- Enable retrieval of a vaccination center's capacity for any given day.
- Provide a list of all vaccination centers within a specific district.
- Allow users to book a vaccination slot, returning a booking ID and decreasing the center's capacity. This also involved checking if the user is above 18 years of age and if the center has the required capacity.
- Allow users to cancel their booking using the booking ID, which should also free up the center's capacity.
Preparation Tips
My key takeaway from this experience is to allocate just a short amount of time, probably no more than 15-20 minutes, for discussing the problem and then focus heavily on writing the code. In such machine coding interviews, interviewers generally expect candidates to deliver a complete, working solution rather than just engaging in extensive discussions about the approach.