Scala & Functional Programming Glossary
A
Akka
Akka is a toolkit and runtime for building highly concurrent, distributed, and fault-tolerant systems on the JVM.
• What is Akka used for in Scala development?
• How does Akka simplify building reactive applications?
Why it matters to you:
Decision Makers: Akka powers high-availability systems that can scale with business demand.
Developers: Akka’s actor model makes concurrency and distributed workloads easier to manage.
API (Application Programming Interface)
APIs allow two applications to communicate with each other using predefined rules and protocols.
• What is an API, and why do developers use it?
• How do APIs support Scala applications?
API-First
An API-first design approach is when APIs are created before application logic, enabling cleaner contracts, scalability, and integration.
• What does API-First mean in software development?
• Why is API-First important for modern systems?
Array (Scala)
An array in Scala is a fixed-size, mutable, indexed sequence of elements.
• Are arrays mutable in Scala?
• When should you use an Array vs. a List in Scala?
B
Backend
The backend is the server-side of an application handling business logic, data access, and APIs.
• What does the backend do in software development?
• How does the backend connect with Scala frontends?
C
Case Class (Scala)
A case class in Scala is a special type of class optimized for immutability, pattern matching, and concise data modeling. Case classes automatically provide methods like equals, hashCode, and toString, making them lightweight and developer-friendly.
• What is a case class in Scala?
• When should you use a case class instead of a regular class?
Why it matters to you:
Decision Makers: Case classes reduce boilerplate, cutting delivery time for data-driven features.
Developers: Case classes integrate smoothly with pattern matching and immutability for safer, cleaner code.
Cloud-Native
Cloud-native applications are designed for the cloud with scalability, resilience, and automation in mind.
• What does cloud-native mean in software?
• How does cloud-native architecture help Scala systems scale?
Why it matters to you:
Decision Makers: Cloud-native design enables flexibility, reduced infrastructure costs, and faster iteration.
Developers: Tools like containers and Kubernetes make deployment and scaling more straightforward.
Collections (Scala)
Collections in Scala are core data structures such as List, Vector, Map, and Set, available in both mutable and immutable variants. They provide developers with flexible ways to store, access, and transform data.
• What collections are available in Scala?
• How do Scala collections differ from Java collections?
Compiler (Scala)
The compiler translates Scala source code into JVM bytecode so it can run on the Java Virtual Machine(JVM), or into native machine code using Scala Native. This makes Scala highly portable and versatile across environments.
• How does the Scala compiler work?
• Can Scala compile without the JVM?
Concurrency (Scala)
Concurrency in Scala is the ability to execute multiple computations in parallel using threads, actors, or asynchronous streams. It ensures applications remain responsive under heavy workloads and high user demand.
• How does Scala handle concurrency?
• What concurrency tools are available in Scala (Akka, ZIO)?
Why it matters to you:
Decision Makers: Concurrency enables systems to handle growth and peak load without sacrificing performance or uptime.
Developers: Scala’s concurrency models (Akka actors, ZIO fibers, Futures) provide clear, safe abstractions for building parallel systems.
D
DataFrame (Spark/Scala)
A DataFrame is a distributed collection of data organized into named columns, similar to a SQL table, optimized for analytics and large-scale processing.
• What is a DataFrame in Spark with Scala?
• How is a DataFrame different from an RDD?
F
Functional Programming (FP)
Functional programming is a paradigm based on pure functions, immutability, and declarative design, reducing side effects and improving code reliability.
• What is functional programming in Scala?
• Why is functional programming often better than OOP?
Why it matters to you:
Decision Makers: Functional programming reduces bugs and improves long-term maintainability, lowering the cost of change.
Developers: Higher-order functions, immutability, and pattern matching make code predictable and easier to debug.
Future (Scala)
In Scala, a Future represents a computation that may complete later, commonly used for asynchronous programming and non-blocking workflows.
• What is a Future in Scala?
• How do you use Futures for concurrency in Scala?
Why it matters to you:
Decision Makers: Futures enable responsive user experiences by avoiding blocked processes.
Developers: Futures simplify async tasks like API calls or database queries with clear, composable syntax.G
GraphQL
GraphQL is a query language that lets clients request exactly the data they need from APIs, improving efficiency compared to REST.
• What is GraphQL, and how is it different from REST?
• How can GraphQL be used with Scala backends?
H
HashMap (Scala)
In Scala, a HashMap is a collection of key-value pairs that provides fast lookups and efficient data retrieval using hash functions.
• What is a HashMap in Scala?
• When should you use a HashMap vs. a Map in Scala?
Headless Architecture
Headless architecture separates the frontend user interface from backend services, connecting them through APIs for more flexibility.
• What is headless commerce or headless architecture?
• Why is headless development popular in modern systems?
I
Immutability (Scala)
Immutability in Scala means once data is created, it cannot be changed, which reduces bugs and supports safe concurrency.
• Why is immutability important in Scala?
• How does immutability improve functional programming?
Implicit (Scala)
Scala implicits are values, parameters, or conversions automatically provided by the compiler to reduce boilerplate and simplify code.
• What is an implicit class in Scala?
• How do implicits simplify Scala code?
Interoperability (Scala/Java)
Interoperability allows Scala code to directly use Java libraries, classes, and tools, ensuring compatibility across ecosystems.
• Can Scala use Java libraries directly?
• How does interoperability make Scala practical for enterprises?
Iterator (Scala)
An Iterator in Scala is a collection type that provides sequential access to elements one at a time.
• What is an Iterator in Scala?
• How does an Iterator differ from a List?
J
Java Interoperability
Java interoperability in Scala means full compatibility, allowing developers to extend Java classes, implement interfaces, and reuse existing Java code.
• How is Scala different from Java?
• Can Scala extend and implement Java interfaces?
JSON (Scala)
JSON is commonly parsed and serialized using libraries like Circe, Play JSON, or uPickle to handle structured data.
• How do you parse JSON in Scala?
• Which JSON libraries are best for Scala development?
JVM (Java Virtual Machine)
The Java Virtual Machine (JVM) is the runtime that executes Java bytecode, providing memory management, garbage collection, and a portable execution layer across operating systems. Scala runs on the JVM (and can interoperate with Java), which is why Scala code is typically compiled to JVM bytecode; alternatives like Scala Native compile to machine code instead.
K
Kafka
Kafka is a distributed event streaming platform that integrates with Scala to process real-time data pipelines and event-driven applications.
• What is Kafka, and how is it used with Scala?
• How does Kafka help process real-time data?
Why it matters to you:
Decision Makers: Kafka powers real-time analytics and event-driven architectures that improve responsiveness.
Developers: Kafka integrates seamlessly with Scala for high-performance, scalable stream processing.
L
Lambda Function (Scala)
A lambda function is an anonymous function that simplifies code by allowing inline logic without named methods.
• What is a lambda function in Scala?
• How are lambdas different from regular functions?
Lazy Val (Scala)
A lazy val in Scala delays the evaluation of a value until it’s first accessed, saving resources and improving performance.
• What is a lazy val in Scala?
• How does lazy evaluation improve performance?
List (Scala)
Lists in Scala are immutable, ordered sequences of elements often used for functional data processing.
• What is the difference between List and Array in Scala?
• Why are Lists immutable by default in Scala?
M
Map (Scala)
A Map in Scala is a key-value collection available in both mutable and immutable forms, used to store and retrieve paired data.
• How do you create a Map in Scala?
• What’s the difference between mutable and immutable Maps?
Why it matters to you:
Decision Makers: Maps simplify handling structured data across applications, improving consistency.
Developers: Scala Maps provide clear APIs for quick lookups and transformations, with immutability for safer code.
Monads (Scala)
A Monad in Scala is an abstraction that represents computations, enabling safe handling of side effects like nulls, errors, and async flows.
• What is a Monad in Scala?
• How are monads used in functional programming?
Why it matters to you:
Decision Makers: Monads standardize error handling and async flows, reducing risks in large systems.
Developers: Monads like
Option,Either, andZIOallow composable, safer code without deep nesting.
Monolithic Architecture
A monolithic architecture is a traditional software design where frontend, backend, and business logic are tightly coupled in one codebase.
• What is a monolithic system in software?
• How does a monolithic platform compare to microservices?
O
Object (Scala)
In Scala, an object is a singleton instance that holds values and methods, often used for utilities or entry points.
• What is an object in Scala?
• How is an object different from a class in Scala?
P
Pattern Matching (Scala)
Pattern matching is a feature that allows values to be checked against patterns, enabling expressive branching and data deconstruction.
• What is pattern matching in Scala?
• How is pattern matching better than switch statements in Java?
Why it matters to you:
Decision Makers: Pattern matching reduces complexity in decision-heavy business logic.
Developers: It replaces verbose conditionals with cleaner, more expressive code.
Polyglot Programming
Polyglot programming is the practice of combining Scala with other languages (Java, Python via Spark, etc.) to use the best tool for each task.
• What is polyglot programming, and why is it useful?
• How does Scala support polyglot development on the JVM?
Why it matters to you:
Decision Makers: Polyglot flexibility reduces risk of vendor lock-in and accelerates innovation.
Developers: Scala’s JVM compatibility makes it easy to integrate multiple languages into one system.
R
Reactive Programming
Reactive programming is a style of development built around asynchronous streams, back-pressure, and event-driven systems.
• What is reactive programming in Scala?
• How does reactive programming improve scalability?
React (Frontend)
React is a JavaScript library for building user interfaces, often paired with Scala services for backend integration.
• What is React used for in web development?
• How does React integrate with Scala services?
Recursion (Scala)
Recursion in Scala is a technique where a function calls itself until a condition is met, commonly replacing loops in functional code.
• What is recursion in Scala?
• How is recursion used instead of loops in functional programming?
S
Scala (Language)
Scala is a hybrid functional and object-oriented language that runs on the JVM and is widely used for backend systems, data engineering, and enterprise platforms.
• What is Scala, and how is it different from other languages?
• Where is Scala used in real-world applications?
Why it matters to you:
Decision Makers: Scala balances enterprise reliability with functional programming power for long-term scalability.
Developers: Scala provides strong typing, concise syntax, and full Java interoperability.
Scala Native
Scala Native compiles Scala code directly to machine code, allowing applications to run without the JVM.
• What is Scala Native, and how does it work?
• When should you use Scala Native instead of JVM-based Scala?
Why it matters to you:
Decision Makers: Native compilation reduces infrastructure overhead in environments where the JVM isn’t ideal.
Developers: Scala Native enables faster startup times and efficient command-line tools.
Spark (Apache Spark with Scala)
Apache Spark (or simply Spark) is a distributed data processing engine where Scala is the primary language for writing fast, large-scale data analytics and machine learning applications.
• Why is Scala the best language for Apache Spark?
• How does Scala integrate with Spark for big data projects?
Why it matters to you:
Decision Makers: Using Spark with Scala unlocks near real-time analytics from massive datasets.
Developers: Scala provides first-class APIs and performance advantages for Spark workloads.
SQL (Structured Query Language)
SQL is used in Scala to query and manage relational databases, often through JDBC or functional libraries like Slick and Doobie.
• What is SQL used for in Scala projects?
• How do Scala applications connect to SQL databases?
sbt (Scala Build Tool)
sbt (Scala Build Tool) is Scala’s standard build system for compiling, testing, and packaging projects, with incremental compilation for speed.
• What is sbt in Scala development?
• Can you use Scala without sbt?
Why it matters to you:
Decision Makers: sbt enforces consistent builds and smooth project delivery across teams.
Developers: sbt accelerates workflows with fast compilation and plugin support.
T
Trait (Scala)
A trait in Scala is a reusable set of fields and methods that can be mixed into classes, similar to Java interfaces but more powerful.
• What is a trait in Scala?
• How do traits differ from Java interfaces?
Tuple (Scala)
A tuple in Scala is an ordered group of elements that may have different types, useful for returning multiple values.
• What is a tuple in Scala?
• How are tuples used in functional programming?
V
Val vs. Var (Scala)
Val vs. Var in Scala compares val, which defines immutable values, with var, which defines mutable variables.
• What is the difference between val and var in Scala?
• Why should you prefer val over var in Scala?
Vue.js
Vue.js is a progressive JavaScript framework for building user interfaces, commonly paired with Scala services through APIs.
• What is Vue.js used for?
• How can Vue.js connect with Scala backends?
Y
YAML
YAML is a human-readable configuration language often used with Scala applications for settings, pipelines, and infrastructure-as-code.
• What is YAML, and how does it compare to JSON?
• How is YAML used with Scala applications?
Z
ZIO (Scala)
ZIO is a zero-dependency library for asynchronous, concurrent, and type-safe functional programming.
• What is ZIO in Scala?
• How does ZIO simplify handling effects in Scala applications?
Why it matters to you:
Decision Makers: ZIO streamlines async and concurrent development, improving developer efficiency.
Developers: ZIO provides composable, type-safe tools for concurrency and error handling without callbacks.
