Welcome Echo Nest!

In case you missed it, we just acquired a company called Echo Nest in Boston. These people have been obsessed with understanding music for the past 8 years since it was founded by Brian Whitman and Tristan Jehan out of MIT Medialab.

From: Erik Bernhardsson

Momentum strategies

Haven't posted anything in ages, so here's a quick hack I threw together in Python on a Sunday night.

From: Erik Bernhardsson

Grails Spring Security Plugin - Logout postOnly setting

Grails Spring Security Plugin - Logout PostOnly Setting

From: Dan Vega

Grails Spring Security Plugin - Logout postOnly setting

I had a question come in about a setting in Spring Security so I thought I would take a quick minute and explain it in case anyone else also has the same question. There is a setting

From: Dan Vega

Creating and testing your first Grails Tag Library

Creating and testing your first Grails Tag Library

From: Dan Vega

Creating and testing your first Grails Tag Library

I created a quick screencast to walk you through creating and testing your first tag lib

From: Dan Vega

Ratio metrics

We run a ton of A/B tests at Spotify and we look at a ton of metrics. Defining metrics is a little bit of an art form. Ideally you want to define success metrics before you run a test to avoid cherry picking metrics.

From: Erik Bernhardsson

Benchmarking nearest neighbor libraries in Python

Radim Rehurek has put together an excellent summary of approximate nearest neighbor libraries in Python. This is exciting, because one of the libraries he's covering, annoy, was built by me. After introducing the problem, he goes through the list of contestants and sticks with five remaining ones.

From: Erik Bernhardsson

Note that ColdFusion 10 Update 13 is "needed" for OS X-only...and some confusion

Some of you may have seen that Adobe released a new hotfix for ColdFusion 10 last night, called Update 13.

From: Charlie Arehart - Server Troubleshooting

More recommender algorithms

I wanted to share some more insight into the algorithms we use at Spotify. One matrix factorization algorithm we have used for a while assumes that we have user vectors $$ bf{a}_u $$ and item vectors $$ bf{b}_i $$ .

From: Erik Bernhardsson

Microsoft's new marketing strategy: give up

I think it's funny how MS at some point realized they are not the cool kids and there's no reason to appeal to that target audience. Their new marketing strategy finally admits what's been long known: the correlation between “business casual” and using Microsoft products:

From: Erik Bernhardsson

Bagging as a regularizer

One thing I encountered today was a trick using bagging as a way to go beyond a point estimate and get an approximation for the full distribution. This can then be used to penalize predictions with larger uncertainty, which helps reducing false positives.

From: Erik Bernhardsson

Still more reasons to make sure you have updated your ColdFusion 10 web server connector

Several weeks ago, I did an entry, CF911: Why/when you MUST update the web server connector for #ColdFusion 10, and may have missed it.

From: Charlie Arehart - Server Troubleshooting

Model benchmarks

A lot of people have asked me what models we use for recommendations at Spotify so I wanted to share some insights. Here's benchmarks for some models. Note that we don't use all of them in production.

From: Erik Bernhardsson

statself.com

Btw I just put something up online that I spent a couple of evenings in my couch putting together: it's a website where you can track any numerical data on the web. Want to know how many Twitter followers you have?

From: Erik Bernhardsson

The Strange Loop 2013

This was my second time at The Strange Loop.

From: Sean Corfield: An Architect's View

Implicit data and collaborative filtering

A lot of people these days know about collaborative filtering.

From: Erik Bernhardsson

CF911: Why/when you MUST update the web server connector for ColdFusion 10/11 and may have missed it

Have you installed or updated CF10 (or 11) and found that you still have problems with it running right, even when you have "fully updated" CF10? In this blog entry, I explain how it may NOT be that "CF 10 is broken" but rather that you may have missed an important step when updating it.

From: Charlie Arehart - Server Troubleshooting

Vote for our SXSW panel!

If you have a few minutes, you should check out mine and Chris Johnson‘s panel proposal.

From: Erik Bernhardsson