Q1. How would you go about.. building an ETL pipeline to handle 3k TPS? A1. Building a data pipeline (i.e. aka ETL) for 3000 TPS (i.e. Transactions per second), which about ~260 million records per day requires distributed, highly scalable, … Read more ›...
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00b: Python variable scopes, assigning types optionally and execution order interview Q&As
Q01. What are the Python variable scopes?
A01. Python uses variable scopes to determine where a variable is accessible and recognized within code. Python follows a strict hierarchy for resolving names, commonly known as the LEGB rule.
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How to prepare for the Java job interviews?
Right preparation will empower you to choose from multiple job offers & negotiate better rates. Expand your horizons into contracting/freelancing with the confidence that you can continuously find work in any job market with the sought-after high paying skills.
Just before attending a Java job interview
1.
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7 Tips to become a self-taught Java or any engineer
If you are new to Java, then best way to gain some hands-on experience is via tutorials and self-taught projects.
Tip #1: Java is very accessible and all the following are available for free. The steps you take may slightly vary depending on your familiarity with Java and its tools.
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00a: Python modules, packages, PYTHONPATH, sys.path, dependencies, etc interview Q&As
Q01. What is a Python Module?
A01. All “.py” or “.pyw” files are Python modules, even scripts. For example, calculation.py that you create is a module. A Python module is a Python file that’s intended to be imported into scripts or other modules.
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33: 50+ SQL scenarios based interview Q&As – Nuances of NULL in SQL
NULL is a special marker used in SQL to indicate that a data value does not exist in the database.
Setup the data on db-fiddle MySQL V9.0 to practice. Make sure to select latest MySQL version to ensure Common Table Expressions (i.e CTE) is supported.
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MySQL import and export of data via command line using mysqldump & mysql
Q01 How do you migrate MySQL database between two servers
A01 This can be done using an SQL Dump Export/Import.
1. Export MySQL Database to a dump File
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mysqldump -h myserver1.com -u root -p mydb1 > mydb1.sql |
There are variations to dump multiple databases:
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mysqldump -h myserver1.com -u root -p --databases mydb1 mydb2 > dump.sql |
To backup specific tables:
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mysqldump -h myserver1.com -u root -p mydb1 table1 table2 > dump.sql |
To backup data using a custom query:
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mysqldump -h myserver1.com -u root -p mydb1 --where="mycolumn=myvalue" > dump.sql |
To copy only the schema but not the data:
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mysqldump -h myserver1.com -u root -p mydb1 --no-data > dump.sql |
2.…
Defining tables in postgresql with primary key, foreign key, unique constraint & data migration example
Uses DB-FIDDLE for the code example with PostgreSQL v17.
Q01 How will you go about defining tables with primary key, foreign keys and unique constraints?
A01 The main purpose of a primary key in a table is to uniquely identify each record.
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SQL procedures vs functions with postgresql (i.e. plpgsql) examples
Q01 What is the difference between SQL stored Procedures & Functions?
A01 Stored procedure does not have a RETURNS clause, but you can use the OUT or INOUT parameter. Stored procedures are transactional whereas functions are not.
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03: Java gRPC with flatbuffers on Docker & Maven tutorial step by step
This extends Java gRPC with flatbuffers & Maven tutorial step by step.
The only difference in this tutorial is to use flatc via a Docker image that has flatbuffers.
This tutorial uses the image neomantra/flatbuffers from Docker hub.
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02: Java gRPC with flatbuffers & Maven tutorial step by step
Prerequisite
Uses Java 17 with Maven 3, and ensure they are installed and in the path. For example in mac, the ~/.bash_profile should have:
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... export JAVA_HOME="$(/usr/libexec/java_home -v 17)" export M3_HOME=/Users/ak/tools/apache-maven-3.9.4 ... export PATH=$SPARK_HOME/bin:$JAVA_HOME/bin:$M3_HOME/bin:${PATH} ..... |
and source it.
1. Create an empty Maven project
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C:\Temp\Java\projects>mvn archetype:generate -DgroupId=com.mytutorial -DartifactId=simple-grpc-2 |
and import or open into an IDE of your choice.
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02: Redis with Redis Insights GUI with Docker compose tutorial
This extends the Redis tutorial Redis server & cli on Docker tutorial step by step.
1. Redis Docker compose file without password auth
Here is the docker-compose.yml file created under ~/projects folder. The server starts without a password for demonstration purpose only.
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26: 50+ SQL scenarios based interview Q&As – Window function (i.e. OVER(…)) with GROUP BY
The below SQL problem can be practiced on MySQL database at db-fiddle or database of your choice. Use latest version from the drop down.
Q1. Given the below data, how will you get the individual sum of the count by score and cumulative sum over the whole data?
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01: Redis server & cli on Docker tutorial step by step
This extends Docker Tutorial – client & server with docker-compose.yml. It assumes that you have a Docker desktop is running in your operating system.
1. Redis Docker compose file without password auth
Here is the docker-compose.yml file created under ~/projects folder.
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01: gRPC with protobuf, Java & Maven tutorial step by step
Prerequisite
Uses Java 17 with Maven 3, and ensure they are installed and in the path. For example in mac, the ~/.bash_profile should have:
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... export JAVA_HOME="$(/usr/libexec/java_home -v 17)" export M3_HOME=/Users/ak/tools/apache-maven-3.9.4 ... export PATH=$SPARK_HOME/bin:$JAVA_HOME/bin:$M3_HOME/bin:${PATH} ..... |
and source it.
1. Create an empty Maven project
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C:\Temp\Java\projects>mvn archetype:generate -DgroupId=com.mytutorial -DartifactId=simple-grpc |
and import or open into an IDE of your choice.
…
Snowflake Snowpark interview Questions & Answers
Both Apache Spark & Snowflake’s Snowpark are used for data engineering use cases like ETL data pipelines, data validations and create data lakes & warehouses. They also can be used in data science use cases like train, develop & provision machine learning models. They can also be used for data...
Databricks Delta Live Tables (i.e DLT) Vs Snowflake Dynamic Tables Interview Q&As
Q01. What is a data pipeline? A01. A data pipeline is a means of moving data from one place (i.e source systems e.g. OLTP) to a destination such as a data lake or warehouse by simultaneously optimising and transforming the data. … Read more ›...
AWS CI/CD interview questions & answers
Over the last few years the number of AWS services that are related to building, managing or deploying software projects on AWS has grown a lot — AWS Amplify, AWS App Runner, AWS Elastic Beanstalk, AWS Code family like CodePipeline, CodeCommit, CodeBuild, CodeStar, CodeArtifact, and Amazon CodeCatalyst. This post does...
Azure Data Factory vs AWS Glue Interview Q&As
Q01. What is the difference between Azure Data Factory and AWS Glue? A01. Azure Data Factory and AWS Glue are two competing serverless PaaS (i.e. Platform as a Service) based ETL and ELT solutions from two major cloud providers Azure and AWS respectively. … Read more ›...
Grafana Loki interview questions & answers
This extends Prometheus monitoring interview Q&As. Both Prometheus & Loki with Grafana Dashboard is an observability tool to monitor, visualize & debug your applications. Dynatrace is a commercial observability tool. Observability is the ability to measure the internal states of a system by examining its outputs. Q01. … Read more...
Prometheus monitoring interview Q&As
Prometheus is an observability & monitoring tool that integrates well with Grafana for visualisation. Prometheus differs from Loki by focussing on metrics instead of logs. Q01. What is Prometheus monitoring? … Read more ›...
Spring Boot Exception handling Interview Q&As
This extends Spring Boot annotations interview Q&As and Java exception handling interview questions and answers. Q01. What is exception handling & why is it important? A01. In Java, Exceptions are objects that are thrown when an error or unexpected situation occurs during the execution of a program. … Read more...
AWS Interview Q&As on ECS, EKS & Fargate
As the demand for containerised applications continues to grow, expertise in AWS ECS has become increasingly valuable for software & data engineers. Q01. What are the benefits of container orchestration services? A02. Container orchestration automates container deployment, management, scaling, and networking. Orchestration tools manage these complexities, … Read more ›...
32: 50+ SQL scenarios based interview Q&As – use of unpivot, lag(..), row_num(..), cumulative sum() and CTE
Setup the data on db-fiddle MySQL V9.0 to practice. Make sure to select latest MySQL version to ensure Common Table Expressions (i.e CTE) is supported. This is not a real life scenario problem, but a simple example that uses many of the SQL syntaxes & techniques. … Read more ›...
Strategy, State, Chain of Responsibility & Observer design patterns interview Q&As
This extends Why do Proxy, Decorator, Adapter, Bridge, and Facade design patterns look similar? What are the differences? Strategy Vs State design patterns Both the strategy & state design patterns are similar, and the UML diagrams look the same, but the intent for both patterns are different. … Read more...
33: Python coding questions – file operations & handling large files
Q01. What are the challenges in handling large files in Python? A01. The challenges with handling large files involve: 1) Memory Usage: Trying to load a large file say a 64 GB entirely into memory can lead to slow performance of an application due to lack of memory, … Read...
32: Python coding questions – Error Handling & Logging
You can either set up your Python environment or use an online interpreter like www.online-python.com. Q01. How do you handle errors in Python? A01. In Python, exceptions are errors detected during execution. … Read more ›...
31: Python coding questions – characters by frequency, anagrams, recursion, etc
You can either set up your Python environment or use an online interpreter like www.online-python.com. Q01. How will you sort a word by frequency of its characters? Input: TREE Output: EETR A01. … Read more ›...
05: Snowflake interview questions & answers – Stored Procedures, Session Variables, UDFs, etc
Q01. What is stored procedure in Snowflake? A01. Snowflake stored procedure lets you perform database operations by executing multiple SQL statements by automating repetitive tasks like cleaning up data by deleting records older than a specified date. … Read more ›...
04: Snowflake interview questions & answers – security, monitoring & recovery
Q01. What is RBAC, which is Role Based Access Control in Snowflake? A01. RBAC is a security model that restricts access to data & resources based on the roles assigned to users. … Read more ›...
In 1999, I pivoted from mechanical engineering to become a self-taught Java expert. Over the past 19+ years, I have built a high-demand contracting career, delivering mission-critical solutions for 13+ top-tier organisations. With a proven track record that has generated over 130+ job offers, I help enterprises solve complex data challenges at scale.
Author of the book "Java/J2EE job interview companion", which sold 35,000+ copies on amazon.com & superseded by this site with 2000+ registered users.
Amazon.com profile | LinkedIn | LinkedIn Group | YouTube
Email: java-interview@hotmail.com
Author of the book "Java/J2EE job interview companion", which sold 35,000+ copies on amazon.com & superseded by this site with 2000+ registered users.
Amazon.com profile | LinkedIn | LinkedIn Group | YouTube
Email: java-interview@hotmail.com
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