We are constantly on the hunt for better ways of doing things. Here's a list of some of the technologies that we use on a regular basis, in no particular order.

Groovy
An awesome little programming language with support for mixed typing that compiles down to Java bytecode
Clojure
Lisp-based functional programming language that compiles to the JVM and JavaScript
Kotlin
A relatively young language on the JVM making
Scala
A versatile language that is quickly becoming known for building powerful data solutions
Spring Boot
An opinionated framework that blends quick prototyping and powerful integrations
Elasticsearch
A RESTful search service that runs on top of Lucene, with rich support for full-text search and deep analytics/aggregations
Docker
Enables portable, lightweight containers for just about anything. Leaves virtualization in the dust
Apache Mesos
A distributed scheduling system that allows you to treat a datacenter as one big computer, distributing batch jobs and long-running processes across a cluster
Kubernetes
A distributed system for automating deployment, scaling, and management of containerized applications
Puppet
A Devops-friendly automated deployment and provisioning toolkit
Amazon Web Services
The ubiquitous cloud platform that powers a fair chunk of the modern web
Google Cloud Platform
A rising competitor to AWS with excellent Kubernetes integration
Drools
A highly-efficient rules engine and complex event processing toolkit, allowing our team to compose complex business logic declaratively and react to changing knowledge over time
Selenium
A powerful tool used to automate browsers for scraping, automation, and testing
Hadoop
A map-reduce oriented distributed processing framework
Apache Spark
A wicked fast, stream-friendly, simpl(er) data processing toolchain
SQL Databases
PostgreSQL, MySQL, DB2 and Oracle mostly
MongoDB
A non-relational document database
Neo4J
A high-performance, transactional graph database supporting highly connected data and complex querying
Redis
A durable distributed caching system
Apache Kafka
Highly performant, persistent and serializable messaging broker originally written by the folks at LinkedIn
RabbitMQ
A high-throughput, language-agnostic messaging system that supports complex routing
Spring Batch
A sane and friendly ETL and batch processing pipeline for the JVM
OptaPlanner
A constraint satisfaction solver, used for building schedules, assigning tasks, and more
D3.js
A data-driven visualization library for JavaScript
React Native
An innovative framework to build mobile apps that blends rapid prototyping with solid performance
Android
A platform powering Android phones, tablets and embedded systems, providing native support for Java and other JVM languages
iOS
A platform powering iPhones and iPads, providing native support for Objective-C and Swift
Jenkins
A web-based continuous integration tool with a robust plugin ecosystem supporting JVM, Javascript, Ruby, Python and Docker builds among others