Engineering 
To give you a sense of the diversity of projects engineers work on, here is a small sample:
Data
We have some of the most valuable data in the industry at LinkedIn. To handle some of this data, we’ve built an awesome recommendation system. The recommendations engine powers many recommendations products at LinkedIn, including Jobs You May Be Interested In, Groups You May Like, and Talent Match. These products use machine learning to provide relevant recommendations, driving monetization and engagement efforts.
We’re also constantly improving questions and answers relevance to connect the recommendations engine with activity data and content tagging to provide novel rankings of question and answer content for users. All that data means we’re also working to make it more accessible using data store, search, messaging, and data services with technologies such as Krati, Rydeen, Zoie, Databus, Hadoop, Voldemort, Bobo, Kafka, and Espresso.
Mobile
An ever growing number of users access LinkedIn through their mobile devices around the world. Our goal is to provide the best possible experience to the user, regardless of which device they’re using. With this mission in mind, we strive to build and enhance LinkedIn applications on platforms like iOS, Android, HTML5, and Blackberry. We’re also working on applications to power the LinkedIn experience on iPad and other tablet devices.
Connect
We’ve built APIs, plugins, and widgets for developers to access the power of LinkedIn data. Connect provides a way to call our APIs from a browser using a simple, consistent JavaScript interface to interact with the fundamental LinkedIn data types (Profiles, Connections, People Search, and so on). Under the hood, we translate requests into a REST call that we make through Ajax. We also provide professional plugins you can install on a site, such as share, member and company profiles, recommend, sign in, and more.
LinkedIn Today
We’ve created LinkedIn Today to give our members the news that matters to them by learning from their networks about what is important to colleagues and the industry they’re in. Today is powered by our news relevance platform, which also powers mobile application news and industry news emails.
InVersion
InVersion is the re-architecting of the LinkedIn online services. We are creating technologies and best practices to enable LinkedIn to scale 10x. We are building new infrastructure to improve resource-oriented (REST) computing, fault isolation, graceful degradation, load balancing, quality of service, parallelism, content assembly, and query processing.
