HubSpot - <a href="http://www.hubspot.com" > - Cambridge/Boston, MA
We create software that helps businesses with their online marketing.  The company is several hundred employees and nearing a hundred in engineering.  Things are organized in small teams and you get to have a big impact.  We were also named the #2 place in Massachusetts to work.
On the backend, we use Java (modern Java with DropWizard, Guice, and the like) and Python (Django).  We love using JSON to get things done.  For storage, there's HBase, Hadoop (for MapReduce jobs), MySQL, ZooKeeper, Redis, and Memcached.  We do great monitoring and deploy hundreds of times a day.  We use CI and have automated deployment.  Don't expect your code to languish in git (we have GitHub Enterprise) for long.
On the front end, we use Backbone.js, CoffeeScript, and jQuery.
We're also looking for iOS and Android engineers.
Work schedule seems flexible (most engineers work 10-6), you get great equipment (like a Retina MacBook Pro and Thunderbolt display), and you get to make a meaningful difference in the product.  There's free drinks (including beer), snacks, etc.
It's a great place to be and hope you come join us!  We have lots of positions open.
Software Engineer: <a href="http://jobvite.com/m?3UQdwgwe" >
JavaScript: <a href="http://jobvite.com/m?3iQdwgwC" >
Infrastructure Automation and Tooling: <a href="http://jobvite.com/m?3wRdwgwR" >
Mobile, iOS, Android, JS: <a href="http://jobvite.com/m?3XRdwgwi" >
Core Data (Hadoop, HBase): <a href="http://jobvite.com/m?34Rdwgwp" >
Reliability: <a href="http://jobvite.com/m?3HSdwgw3" >
Technical Lead: <a href="http://jobvite.com/m?3zSdwgwV" >