Coinbase Senior Software Engineer Interview Questions

1.Describe a time when you saw a critical problem that wasn't officially your responsibility but you stepped in to solve it anyway. What was the problem and how did you approach it?

2.Tell me about a time when you took ownership of a project or system that was failing, even though you weren't originally responsible for it. What was broken and how did you turn it around?

3.Tell me about a time you made a technical decision that hurt short-term velocity but was right for the long-term architecture. What pushback did you get and how did you handle it?

4.Tell me about a time you obsessed over getting a product detail right because you knew it would significantly impact the user experience. What did you focus on and how far did you go?

5.Walk me through a time when you pushed your team to significantly improve their code quality or engineering practices. What was broken, how did you drive the change, and what resistance did you face?

6.Describe a situation where you had to choose between a feature your team wanted to build and what you believed was right for the product's mission. How did you handle that conflict?

7.You're building a new API endpoint that needs to validate cryptocurrency addresses for 50+ different blockchain networks. What's your design approach?

8.Write a function in Go that safely processes incoming webhook events from multiple blockchain networks, ensuring exactly-once delivery even during service restarts.

9.We're seeing intermittent 503 errors from our PostgreSQL database during high trading volume periods. The database isn't hitting CPU or memory limits. Walk me through your debugging approach.

10.Our Kubernetes pods running Go microservices are experiencing memory leaks that cause restarts every 12-24 hours. How would you identify and fix this?

11.You're working on a trading order matching engine that processes 100,000 orders per second. A client reports that their limit orders are sometimes executing at worse prices than they specified. How would you investigate this?

12.You need to design a real-time price feed system that delivers cryptocurrency prices to 10 million mobile app users with sub-100ms latency. What's your architecture?

13.You need to build a fee calculation service for Coinbase that can determine trading fees in real-time for millions of users across spot trading, futures, and staking with different tier structures.

14.Design a blockchain node management system for Coinbase Cloud that can automatically provision, monitor, and scale nodes across 20+ blockchain networks for enterprise customers.

15.Walk me through designing a notification system for Coinbase that can instantly alert 100 million users about price movements, security events, and transaction confirmations across mobile and web.

16.Design a compliance monitoring system that can scan every transaction on Coinbase Exchange in real-time to detect money laundering patterns and automatically file suspicious activity reports.

17.You're designing a custody service for Coinbase Prime that needs to store billions in crypto assets for institutional clients. How would you architect the key management and transaction signing infrastructure?

18.Design the order book system for Coinbase Exchange that can handle 500,000 orders per second across 200+ trading pairs while maintaining fair price discovery.

19.Tell me about a time you had to influence an engineering team or tech lead at a higher level than you to adopt your approach. What was your strategy and what was the outcome?

20.Describe a time when you coached a teammate through a complex technical problem they were struggling with. How did you approach it and what was the result?

21.Walk me through a time when you had to lead a cross-functional initiative where the technical and business stakeholders had fundamentally different views on the solution. How did you navigate that?

22.Tell me about a time when you had to quickly learn a new technology or domain to solve a critical problem. How did you approach the learning and what was the outcome?

23.Describe a situation where you had to maintain team morale and productivity during a period of significant uncertainty or setbacks. What specific actions did you take?

24.Tell me about a time when you made a decision that went against popular opinion on your team because you believed it was right for the product or users. How did you handle the pushback?

25.If we wanted to launch Coinbase in a new country like Brazil, estimate how many customer service agents we'd need to hire in the first year. Walk me through your calculation.

26.Coinbase Prime custody holds about $80 billion in crypto assets. If we charge 50 basis points annually for custody, estimate our yearly revenue from this service and explain what drives the biggest uncertainties.

27.Base blockchain launched 6 months ago and we're seeing 50,000 daily active users. Estimate what that number could realistically be in 2 years and explain your reasoning.

28.We're seeing users abandon the Coinbase app during the identity verification flow at a 40% rate. This verification is required by law. How would you approach reducing this abandonment while staying compliant?

29.Estimate how much revenue Coinbase loses per day when our exchange goes down for 1 hour during peak trading hours. What assumptions are you making?

30.Coinbase Wallet supports 100+ different cryptocurrencies, each requiring different transaction fee estimation. A user complains their Ethereum transaction has been pending for 6 hours. How would you systematically debug this?