These backend engineer interview questions are directly sourced from real hiring managers and they are ready to use.
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8 good backend engineer interview questions
- What does REST stand for?
- What do you understand by NoSQL databases?
- What is SQL injection?
- How do you handle data migrations in a production environment?
- Describe the differences between a thread and a process.
- How do you ensure the security of data in transit?
- What are the key differences between a relational database and a non-relational database?
Here are 4 real-life interview questions and 4 additional questions with sample answers to help you identify the best candidates for this role.
1. What does REST stand for?
REST stands for Representational State Transfer. It’s an architectural style that defines a set of constraints to be used when creating web services.
“REST stands for Representational State Transfer. It’s a standard for building web services that work best on the Web.”
2. What do you understand by NoSQL databases?
NoSQL databases are non-relational databases that can store and retrieve data in ways that don’t involve tabular relations like SQL databases.
“NoSQL databases are designed to scale out by distributing the data across many servers. They are schema-less, and data can be stored in multiple ways, such as column-oriented, document-oriented, graph-based, or key-value store.”
3. What is SQL injection?
SQL injection is a code injection technique that attackers can use to run malicious SQL statements in a web application’s database.
“SQL injection is a type of attack where an attacker can execute arbitrary SQL code on a database. It happens when user input is incorrectly filtered and can lead to unauthorized viewing of data, corrupting or deleting data, and other malicious activities.”
Now, let’s proceed with recommended additional questions to round out the interview:
5. How do you handle data migrations in a production environment?
Data migrations involve moving data from one system or format to another, often during software upgrades, system integrations, or cloud adoption.
“I always ensure to backup data before any migration. I then use migration scripts or tools, test the migration on a staging environment first, and ensure data integrity after the migration.”
6. Describe the differences between a thread and a process.
A process is an independent program in execution, whereas a thread is the smallest unit of a process that can run concurrently with other parts (threads) of the same process.
“A process has its own memory space, while a thread shares its memory space with other threads within the same process. Threads within the same process can communicate more easily than processes can.”
7. How do you ensure the security of data in transit?
Securing data in transit means protecting data as it’s transferred between systems, devices, or applications.
“I ensure data security in transit by using encryption protocols like TLS. Using HTTPS instead of HTTP is also a must. Additionally, VPNs and secure file transfer protocols can be used.”
8. What are the key differences between a relational database and a non-relational database?
Relational databases use tables to store data, while non-relational databases can use a variety of data models, including document, key-value, and graph.
“Relational databases are structured and use SQL for querying. Non-relational databases are more flexible in terms of storage and structure, and they often offer horizontal scalability.”
What does a good Backend Engineer candidate look like?
A proficient Backend Engineer should have a deep understanding of server-side logic, be proficient in multiple programming languages, understand database operations, and prioritize security. They should also be adept at problem-solving, be continuously learning, and be able to collaborate with front-end developers and other team members.
Beware of candidates who lack problem-solving skills, aren’t familiar with modern backend technologies, or don’t prioritize security. Also, those who can’t explain complex concepts simply or aren’t open to feedback can be concerning.