Blockchain Interview Discussion

Question

Blockchain has been an interest in IT recently, with lots of career opportunities. So guys, if you have any questions regarding Blockchain interview or if you want to share your interview experience which could help others, please put it up on this thread so that it can help others.

You can also go through: https://goo.gl/knLfru

for more on Blockchain interview questions..

Answer 1

Hello everyone here is an updated blog for Blockchain Interview Questions. Your last minute sheet to brush up most frequently asked Interview Question.

Refer the Blog "Top 55 Blockchain Interview Questions You Must Prepare In 2019".

All the best to everyone.

Answer 2

Hi.. I recently attended an interview and the first question was "What do you know about blockchain?". While explaining what i knew about blockchain, i told that blockchain was a distributed ledger. Then I was asked the difference between distributed ledger and distributed database. I did not know the answer then, but I have been wondering what the answer is.. Can you please explain the difference?

Comments

Hey Javed,

Firstly, Blockchain is not Distributed Ledger but blockchain is a form of Distributed Ledger. What makes Blockchain
distinct from Distributed Ledger is the structure of Blockchain. Blockchain is a list of blocks that keep on adding
periodically which contain a list of records.

The main difference between a Distributed Ledger and a Distributed Database is:

In Distributed Database, the data is distributed among different machines and these machines are trusted and
expected not to try to attack on the integrity of the data stored.

In case of Distributed Ledger, the data is distributed among machines that do not trust each other and due to this,
a consensus mechanism is used to maintain the system.

Answer 3

I have only heard about Proof-of-work and Proof-of-stake algorithms when reading about consensus.. Are there any other consensus algorithms apart from these two?

Comments

Hey Pradeep,

Yes, there are other consensus algorithms. I am listing a few below.

1. Proof of Activity
2. Proof of Elapsed Time
3. Proof of Authority
4. Proof of Burn
5. Proof of Importance
6. Proof of Capacity

Answer 4

Sir, in my interview I was asked which all geth APIs i know. I said eth and web3 (because they are popular). The interviewer expected me to give more answers but i did not know. So i wanted to know which are other APIs than eth and web3?

Comments

Hey Zahir,
Some of the geth APIs apart from eth and web3 are:
1. Admin
2. miner
3. net
4. personal
5. shh
6. debug
7. txpool

Answer 5

Hello, my suggestion for people who are preparing for Blockchain interview is that along with Blockchain basics, learn concepts of Encryption and hash. Learn about types of encryption and how hashing works. Especially concentrate on SHA256 hash. All the best.

Comments

Thanks for your suggestion Vipul!

Answer 6

In my interview I was asked to mentions some applications of Blockchain. I had read about it (just by-hearted the list) and I started telling cryptocurrency, Bank management system, Brokering services, Identity management..... The interviewer stopped me and asked me to explain how blockchain is used in Identity management. Well, i did not know the answer because i had not read about it. So I want to how Blockchain application in Identity Management.

Comments

Hey Apurv,

Blockchain can be used in Identity management to prevent fraud. The data in Blockchain in immutable so the data regarding identity of a person in Blockchain can not be altered. It prevents forging of identity documents to gain benefits.

This is how Blockchain can help manage Identity.

Answer 7

I was asked to name two types of records that are present in the blockchain database. I didn't know at that moment. Later when I googled it, I found this edureka blog and I regret not going through the blog before the interview.