Blockchain Software Engineer Interview Questions
& Process
Real candidates share what happened, how many rounds they had,
and how the experience turned out.
Based on 13 interview experiences · FREE TO READ
Candidate interview experiences
First-hand accounts from people who interviewed at Blockchain.
Blockchain
Software Engineer
Entry Average Positive experience Accept offer 3 rounds
Interview process
Recruiter call Technical screen Onsite Background check Offer
Interview formats
Behavioral Technical Coding System Design
So, the interview started with a recruiter screening call. It was basically to see if my background lined up with what they were looking for, if my career goals matched, and if I fit the company vibe. They didn't get into any technical stuff. Then came this big technical session, which was split into two parts. First, there was this hands-on technical scenario. It wasn't your typical LeetCode-style problem. They gave me a business situation and some starter code, and I had to build a working solution. It was pretty tough 'cause the business context was kinda out of the blue, so I had to quickly figure out what they actually wanted before diving into the code. Right after that, it was the system design part. This was all about my understanding of architecture and how systems are put together. They asked me questions about designing systems, covering different areas to check how I'd handle complexity, scaling, and how things fit into the bigger picture. The last interview was with a Technical Lead. This was more about finding the best place for me within the company. We talked about which team might be a good fit and where my skills would be most useful. I also got to discuss what tech stacks I liked, what kind of projects I was interested in, and how I saw my career growing. Honestly, the whole experience was pretty good and felt collaborative. Everyone was super nice and helpful. The trickiest bit was definitely that business scenario coding question (Stage 2A) because it wasn't like the usual coding tests, and it took a bit to get my head around the specific problem and what they were aiming for.
Confirmed questions3 questions
- Can you detail the fundamental principles of database reliability?
- What are the four characteristics of ACID transactions?
- Why is it crucial to adhere to the four properties of ACID transactions for maintaining data integrity in systems that handle transactions?
Blockchain
Software Engineer
Senior Average Negative experience No offer 2 rounds
Interview process
Recruiter call Take home
Interview formats
Coding Technical
A recruiter reached out via LinkedIn for an initial chat. Then, I was given a take-home assignment. I had a week to build it, but honestly, you don't need that much time. The submission would be judged, and I wouldn't advise spending more than 2-3 days on it, or adding extra features like loading states or error messages because they weren't really valued.
Confirmed questions6 questions
- Can you build a basic Next.js app that works as an HD Bitcoin wallet?
- The wallet needs to let users request BTC payments on the testnet.
- Also, it should generate QR codes that can be shared for these payment requests.
Blockchain
Software Engineer
Mid Average Positive experience Accept offer 4 rounds
Interview process
Recruiter call Technical screen Technical screen Onsite
Interview formats
Coding Technical Behavioral
The interview process has 4 stages. First, a screening call with HR. Second, a pair programming session with an Engineering Manager. I was nervous about this, but it wasn't a Leetcode-style question, so I stayed calm and focused on understanding the problem. The interviewer was helpful and gave some guidance. Third, a technical session with another Engineering Manager, and fourth, an onsite interview with the Engineering VP. Stages 3 and 4 involved typical technical and behavioral questions where I was asked to draw from my past experiences. The process moved quickly, taking about a month. The HR team was also helpful and responsive.
Confirmed questions1 question
- Do you have knowledge of or experience with concurrent programming?
Blockchain Software Engineer Interview Questions
Quoted word for word from Blockchain interview reports.
“Can you design a function that takes a float and returns whether that exact float has been seen before? bool is_seen(float num);”
Read reports →“What are the four characteristics of ACID transactions?”
Read reports →“Build an Orderbook with Add (side, px, size), Update(px, side), and delete(px) functionalities.”
Read reports →“Why is it crucial to adhere to the four properties of ACID transactions for maintaining data integrity in systems that handle transactions?”
Read reports →“Can you build a basic Next.js app that works as an HD Bitcoin wallet?”
Read report →“Regarding unique_ptr on a 64 architecture, what is its size? What is the complexity for inserting an element into an std::array? And for an std::map? What is the cache line size on x64? What is the page size? What's the default Stack Size on Linux? Regarding an L2 book, what is the complexity to add or change a price/qty? Note: the interviewer considers this a price->qty book, not a top-5 or top-10. What is the complexity of a sweep? For std::vector or std::map, what does operator[] return? And what does the const version of operator[] return? What is the stack size on Linux?”
Read report →“Can you explain Kubernetes pods and services as if you were talking to someone who has no prior knowledge of them?”
Read report →“Can you detail the fundamental principles of database reliability?”
Read report →“What are your thoughts on Blockchain Technology?”
Read report →Formats, difficulty and experience
Across all 13 Blockchain interview reports.