An API rate limit is the number of API calls that a user can make during a specific time interval. If this limit is exceeded, the user or IP needs to be throttled so that any further requests that are made to the API by that user or IP fail. Let’s discuss how to design a rate limiter.

Why Is Rate Limitation Required?

Services can only serve a limited number of requests per second. If each user can make as many calls to the API as they like, the overload of requests can starve the servers and affect the response times for other consumers. By…

Grokking the Advanced System Design Interview

And, Educative is back with a sequel to likely the most popular course on its platform Grokking the System Design Interview. The sequel is aptly titled Grokking the Advanced System Design Interview and moves beyond the run-of-the mill system design questions being asked around in interview circuits these days.

The course is a collection of summaries describing the internal workings of widely used and deployed distributed systems in use today. The list of systems discussed in the course include:

  1. Dynamo
  2. Cassandra
  3. Kafka
  4. Chubby
  5. GFS
  6. HDFS
  7. Big Table

Most of these systems belong to the Big Data/Cloud space and implement concepts…

Negotiating Compensation with Tech Companies

In business, you don’t get what you deserve, you get what you negotiate.” — a quote by Chester L. Karrass, is the tag line of the latest course, Grokking Comp Negotiation in Tech on’s platform. Grinding through hundreds of LeetCode questions and memorizing dozens of System Design problems can get you your dream job but not necessarily the highest financial compensation package. Did you know that the total comp for Facebook software engineers working at level E5 can vary wildly, as much as $100K between the highest and lowest offers? Surely, the interview performance can dictate a candidate’s offer…

Do you have any questions for me?” is how almost all tech interviews end. It may be hard to come-up with good questions to ask your interviewer and here are some ideas and questions we present that can demonstrate your maturity as a software developer and genuine interest in the position:

Company-specific Questions

  • What is the one thing that you don’t like about the company?
  • If you could, what would you like to change about the company’s culture?
  • What areas of growth do you see for the company in the future?
  • Who are the primary competitors of the company?
  • Can…

Least Recently Used (LRU) Cache is a very common problem asked in interviews. The key to the problem is to realize that a hash table and a doubly linked list can be used to solve it efficiently. Another variant of the LRU problem is the priority-expiry cache. The Educative’s course on Big-O Notation for Coding Interviews and Beyond solves this problem using two heaps and two hash-tables, but isn’t conclusively the best solution. If you have a better solution, we’d love to hear from you and share your solution here with due credits. …

Clearly, Educative is more popular than DataCamp just going by Google’s search trends as shown in the screenshot below. Though DataCamp has raised more money than Educative but caters only to the Data Science niche., on the other hand, takes a bold approach and offers courses on its platform covering the entire spectrum of tech. Essentially, both are market places for online courses, some written by independent authors while other written by the platform’s content team. shown in blue vs in red’s offers diverse courses but lacks the concentration and depth of Data Science content and material available at DataCamp. If you are looking…

If you landed on this blog entry, you are likely looking to buy’s courses for less than they are advertised for. Here are the three ways you can get them on the cheap:

  • Educative allows you to audit some courses for free. The offer may show up on your Educative account randomly or you may request them explicitly.
  • Educative runs promotions throughout the year on various occasions to give discounts, such as the one running now for Black Friday. The current promotion has been extended till the end of this year.
  • Most importantly,’s prices are adjusted geographically, so…

Behavioral Interviews

The Bay Area sun shone bright and golden in the blue skies of summer of 2013. I was shackled to an uninteresting job at the Microsoft campus in Mountain View. A few blocks down the road stood LinkedIn’s hip and trendy offices, teeming with youthful engineers, typical of a Silicon Valley startup. The contrast was stark. Microsoft’s dull buildings were laid with grey carpets, and not-so-motivated engineers walked over them. …

Artificial Intelligence/ Machine Learning/ Data Science

Data Science is taking off and the number of jobs in the field is exploding. is ahead of the curve and offers the following list of courses you can study through to either gently dip your toes into AI/Data Science/Machine Learning or prep for your next interview.

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Musings, opinions and short essays on technology

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