Five quizzes with 20 multi-choice questions each - with detailed explanations on just what you need to know and reference links - on the following topics:

(1) Networking – URL, HTTP, DNS, HTML/CSS/JS, CORS/JSONP/XSS, TCP/UDP, SSL/TLS, OSI, CIDR…

(2) Databases – batch/streaming, SMP/MPP/EPP, NoSQL, ACID/BASE, eventual/strong consistency, replication, sharding, data formats, MapReduce, 2PC, constraints, referential integrity, UDFs, isolation levels, locks, SQL injection…

(3) Cloud Computing – throughput/latency, high availability, fault-tolerance, horizontal scale, architecture styles, event-driven/messaging, streaming, retry/throttling patterns, proxies, DDoS, load balancers, CDNs, Docker, deployments, RBAC, encryption, SSL/TLS certificates, OAuth…

(4) Data Structures – implementation of linked lists, queue/stack, heap and priority queue, enumerator/iterator, hash tables with collisions, trie, LRU cache, closures, pointers, garbage collection, asynchronous/multi-threading, consistent hashing…

(5) Design Problems – real-time recommendations, tiny URL compression algorithms, autocomplete with Trie, web crawlers with no infinite loops, object-oriented design, chat server with web sockets, Twitter/Instagram/Dropbox/Uber clones, summarization with scale and message queue, API rate limiter, state machine, interview questions and number estimates…

An interactive version of this book has been provided on Udemy as "System Design: 100 Job Interview Questions".

Learning how to design a data warehouse may be difficult. Ralph Kimball has some great legacy books on the dimensional modeling techniques, but they are verbose, with complicated examples. Our illustrated examples here are kept simple on purpose, to help you better understand complicated concepts like periodic snapshot fact tables, degenerate dimensions, late arriving facts or dimensions.

We focus our puzzles on Ralph Kimball's dimensional modeling techniques, but we also introduce you to Extract-Transform-Load (ETL) basics, OLAP fundamentals and some other important things you must know about data warehouses in general. We dive deep into slowly changing dimensions (SCD), with other illustrated examples to help you get the ideas in no time.

You need just some basic prior knowledge about Data Warehouses in general. The explanations and external references from the answers to our questions will help you learn the rest. We also assume you already have some basic background in data modeling for relational databases, and SQL.

These puzzles are for Software Developers and Engineers, Database Engineers and Architects, or Data Analysts. Difficulty level is from beginner to advanced.

We've split the 100 questions into 5 quizzes with 20 single and multi-choice questions each. Try solving each quiz separately, writing down on a piece of paper the answer to each question. Then go to the Answers and Explanations section, and learn more from our solutions to the puzzles. Follow the links to external references for a deep dive on the subject.

An interactive version of this book has been implemented on Udemy as 100 Puzzles to Learn Data Warehousing.

These 100 puzzles, with multiple levels of difficulty, can help you quickly improve your essential knowledge and problem solving skills in LINQ (Language-Integrated Query).

Master the functional programming style of LINQ for Object on immutable sequences. We focused on the fluent method notation. You'll find some query notation as well, but no LINQ for XML. We covered most if not all Enumerable standard query operators. Our strategy was to skip the trivial, avoid the clutter, but remember the basics and repeat what really matters.

We've split the content into 5 quizzes with 20 puzzles each. The puzzles are introduced as either coding problems with alternative possible solutions, or multiple-choice knowledge-related questions. In a separate section, all puzzles have detailed answers, explanations and references you can check after you first try to solve them with no hints.

More than 50 coding problems have one-click live C# source code you can run online and change as you wish. Dozens of problems are inspired from the most voted questions on Stack Overflow. Last quiz has problems asked in real Job Coding Technical Interviews, as described on LeetCode and elsewhere.

You must be already proficient in C# and comfortable with lambdas, extension methods and other advanced techniques. You must already know the basics of LINQ, as we don't teach LINQ here: these puzzles help you get better in LINQ.

The target audience starts with beginner C# developers and extends to expert C# programmers looking to test their skills. And have some fun in the process. Intermediate C# developers could better understand LINQ and its functional programming style.

We also target Software Engineers preparing for job coding interviews, or certification exams that require coding. LINQ is an essential component in solving complex algorithms and efficiently parsing data collections.

An interactive version of this book has been implemented on Udemy as "100 Interactive LINQ Puzzles".

Become an expert in Neo4j Cypher programming!

• Learn advanced Cypher through a large collection of complex queries.

• Study complex and advanced Neo4j Cypher queries.

• Queries collected from the Knowledge Base, Neo4j forums, Q&A sites.

• Each query, good or bad, is properly discussed in the answers.

• Look at multiple ways to implement a Neo4j Cypher query.

• Each answer contains a list of references for the addressed topics.

• We present and discuss gotcha tricks, and unusual use cases.

The book contains:

• Three big puzzles, with 10 questions each.

• Each question is with either a single-choice or multiple-selections.

• Each question has between three and six choices.

• Each choice is a Cypher query you must select as either a good or bad answer.

This book contains two original and high-quality practice tests of 50 questions each. They will help you learn and/or better understand Apache Cassandra, especially its CQL (Cassandra Query Language).

• Each practice test has 50 questions. For more challenge, time them up for 60 minutes, and consider a 80% passing score.

• Domains: Data Modeling, Data Definition, Data Types, Data Search, Data Modification, Functions, CQL Shell, Performance, Security.

• Almost every question offers 3-4 choices. Most questions are single-select, a few with variable multi-selections.

• Every question is unique and original, elaborated, meant to teach you something essential, with no waste of time.

• Detailed explanations with external references for any possible choice, in each practice test question.

• Reference links to relevant pages from the Apache Cassandra Documentation, DataStax documentation, StackOverflow questions.

• While this will also help you pass DataStax certifications exams, the questions here may be very different from the exams.

• Search by title for the same e-book as LIVE practice tests on Udemy.

What you will learn or better understand

• How to properly design tables in CQL. Data modeling with Chebotko diagrams and proper key choices.

• How to properly query Cassandra tables without paying a price in performance.

• How to properly use the partition, clustering or primary keys, in WHERE and ORDER BY clauses.

• When and what keys you may skip in a filter expression or in an explicit query sort order.

• When to create a new denormalized table, secondary index or materialized view.

• Major differences between SQL and CQL, with plenty of examples.

• How to avoid traps, gotcha situations, hidden issues you may not know about.

• What the mysterious TTL actually does. When whole rows may suddenly disappear or not.

We offer five quizzes with 20 questions each. The questions are either multi-choice or multi-selection, with exactly five total choices each. In a following section, each question has the answer(s), with detailed explanations and at least one reference link:

(1) Most Common Questions - this section presents the most common questions in a typical Behavioral Interview. Walk through each one of them and remember the right answers and the eventual traps.

(2) Traps to Avoid - this section will focus on the traps to avoid in the most common questions from a Behavioral Interview, as presented before.

(3) The STAR Technique - this section has quizzes about the STAR technique, which is a structured manner of responding to a Behavioral Interview question by discussing the specific Situation, Task, Action, and Result.

(4) Company Values - this section emphasizes on typical core Company Values, that frequently come up in most of the Behavioral Interview questions.

(5) Written Communication - this section relates to styling and Behavioral-specific areas found in your resume, cover letters or other written communication.

An interactive version of this book has been provided on Udemy as 100 Behavioral Job Interview Questions.