Wayfair Tech Blog

Last weekend was the inaugural run of the Northeast PHP Conference in Boston. Wayfair was a gold sponsor, so we bought t-shirts, paid for apps and beer at the Saturday night event, and also sent about 15 engineers to the event. I gave a talk on High Performance PHP, and we had a blast. Check out the slides from my talk. The feedback was great, and we look forward to sponsoring the conference again next year!

Wayfair Tech Blog

Measuring CDN Performance Benefits with Real Users

A couple of weeks ago I ran a test with WebPagetest that was designed to quantify how much a CDN improves performance for users that are far from your origin. Unfortunately, the test indicated that there was no material performance benefit to having a CDN in place. This conclusion sparked a lively discussion in the comments and on Google+, with the overwhelming suggestion being that Real User Monitoring data was necessary to draw a firm conclusion about the impact of CDNs on performance. To gather this data I turned to the Insight product and its "tagging" feature.

Wayfair Tech Blog

Webops for Python, part 2: the how-to

In part 1 of this 2-part series we used a comic strip to depict Python programmers and web operations folk working together to figure out how to deploy some scientific computing to an e-commerce site. Joking aside, let's describe exactly what were were trying to accomplish, and how we did it.

Wayfair Tech Blog

Wayfair Engineering Open Board Game Night

At Wayfair Engineering, we’re not just proud of the elegant technical solutions we implement, but we’re also proud of our team. As part of our team bonding, we have frequent “Pod Outings,” activities that can be organized by any member of the Engineering team. Some recent Pod Outings have included a trip to play aerial dodgeball at SkyZone, a paintball outing where we honed our squad tactics, a relaxing day of golf, and our recurring breakfast club before work. Sometimes the best outings are the ones we host at our offices, as we recently did when we decked out our 24th floor with food, beer, and every gaming system we could lay our hands on.

Wayfair Tech Blog

The little program that could

It started as a proof of concept prototype in the fall of 2010. The idea came from a meeting where we were discussing the porting of our storefront codebase from classic ASP to PHP. One of the discussion points was how to avoid simply porting the same logic from one scripting language to another, but rather finding ways to move some of that logic to other more suitable platforms, including service oriented solutions. The little program was written as a self-hosted WCF service written in VB.NET running on my Windows XP box as a console application. It implemented a RESTful API service that returned the number of products in a customer’s shopping cart. Really simple and modest in scope, the thing worked like a charm. I made a presentation about it during one of our Wayfair Engineering Lunch and Learn sessions about a week later. So far, so good.

Wayfair Tech Blog

The 24-Hour News Cycle

A few weeks ago, we celebrated Inc! Magazine’s great cover story about us, including an internal poll of our favorite item from the photo shoot (results: tie between the purple dragon and giant giraffe). Unbeknownst to us, however, the story was later picked up by Yahoo!’s news feed on April 10th and posted to the scroller on their homepage. This is where our story begins…

Wayfair Tech Blog

Software Adaptations - Wayfair's Partners

You would think data replication is a piece of cake these days given all the advances in database technology, and that’s true for the most part when you’re dealing with databases of the same type, but when you have to replicate parts of your product catalog with other companies, things get a bit tricky. At Wayfair Engineering we’ve figured out how to make it happen by creating a great software solution that keeps our retail partner operations working like a well-oiled machine.

Wayfair Tech Blog

Eliminate Implicit Conversions

At Wayfair, we are never done. And the DBA team here is a true example of it. We are constantly looking to improve performance and we rigorously tune our databases on a daily basis. We are always looking at ways to have our queries run faster – by maintaining indexes, optimizing queries and procedures, creating any missing indexes based on query usage, generating statistics on currently running queries, and filtering out queries with top CPU usage, among other improvements. Of late, we’ve been trying to eliminate any implicit data type conversions that happen at runtime. Implicit data type conversions come with cost, especially when the conversion is performed at the column side of the query – not the literal side. We have had scenarios where for high volume processing jobs (processing millions of records) we had index scan execution on queries due to implicit conversions. A simple demonstration of an implicit conversion is: WHERE a.OrderID = b.OrderNo; a.OrderID being varchar(30) and b.OrderNo is nvarchar(30). Here the execution plan would do an implicit cast to nvarchar(30) and would perform an index scan operation on the millions of records – with you waiting endlessly for the query or job to finish.

Wayfair Tech Blog

Recommendations with Markov Clustering

Our story begins in Holland in 1997, where a researcher named Stijn van Dongen, who is pretty good at Go, has a 5-minute flash of insight into modeling flows with stochastic matrices. He writes a thesis about it and makes a toolkit called MCL with a free software license.