We recently decided to sponsor the Erlang Ecosystem Foundation. We believe this is a very important initiative and we’re trying to contribute with it as much as we can. Learn more about it, the reasons behind our sponsorship, and the other ways in which we’re contributing in this article. 5-7 minute...

In celebration of International Women’s Day 2019 and National Women’s History Month, we’re continuing our tradition of highlighting Tech Women at AdRoll Group. I love reading biographies, but not for the reason you might be thinking. You see, I love origin stories. No two people take the same path t...

Dialyzer is a great tool to validate Erlang code, but it might slow down your development process if devs are applying it to huge codebases constantly. Particularly if that code was never analyzed with it. This article is our answer to the big question: How to start using dialyzer in a huge project ...

Grace Hopper is happening on October 2-4 2019 and the Call for Participation, Abi Award nominations, and Scolarship applications are now open! Here is why we love Grace Hopper. 10-15 minute read In September 2018, sixteen Rollers joined around 20,000 attendees from all over the world for Grace Hoppe...

Autoscaling was a great addition to DynamoDB and it lets you forget about assigned capacity. Here’s how we implemented our own algorithm to improve on this idea. 10-15 minute read DynamoDB is a NoSQL key-value database service provided by AWS. We use it at the core of many of our systems, since the ...

Introduction A primary responsibility of the data science team at the AdRoll Group is to determine what we should bid in real-time auctions for ad inventory. Among other things, our bid price is dependent on the type of auction in which we are participating. Second-price auctions, where the highest ...

/**/ We reduced by over 60% the EC2 instance cost of our 1000+ node globally-distributed log-producing application by migrating it entirely to EC2 Spot Fleet. We discuss some of the issues we faced and also present the log data recovery mechanism which helped enable this migration. 15-20 minute read...

Dead code (as in functions that are not used anywhere) tends to pile up in big projects if you leave them unattended. Using one of Xref’s most underrated features, you will be able to detect and remove what you do not need anymore. 10-15 minute read We have already written several articles in this b...

The attribution team at AdRoll computes metrics out of petabytes of data every night. This is accomplished using a batch processing pipeline that submits jobs to AWS Batch. In this blog post we discuss how this is organized and orchestrated with Luigi. We announce Batchiepatchie, a job monitoring to...

When the leadership team decided to move AdRoll HQ to the spacious new location in the Mission, one has to wonder whether they had events such as last Wednesday’s evening gathering in mind. A crowd of 100+ Python enthusiast filled the all hands area to share in some delicious catered food and drinks...

As a performance-oriented growth platform, AdRoll is always looking for ways to improve our users’ ad experience. Our Dynamic ads are the highest performing ad type, but some of the underlying systems were becoming increasingly hard to scale and change. In this post, we will talk about how moving th...

Recently I attended the Data Driven Women Meetup event hosted by AdRoll Group, and felt inspired to share this blog post, from a man’s perspective. I heard of the event through my work (AdRoll Group) and after reading up on the event details, I realized four of my women colleagues were the featured ...

Highlights from the BuzzConf BA 2018 conference. April 26th, 2018 Buzzwords as the Motivation for a Conference As google promptly help us define, buzzword is… a word or phrase, often an item of jargon, that is fashionable at a particular time or in a particular context. In the world of software, the...

Click prediction may be a simple binary classification problem, but it requires a robust system architecture to function in production at scale. At AdRoll, we leverage the AWS ecosystem along with a suite of third party tools to build the predictors that power our pricing engine, BidIQ. This is a to...

Highlights from the CodeBeam SF 2018 conference, March 15-16 2018 Once was Erlang Factory The name has changed - yearly in fact, for the past few years - but this conference is always a destination for the Erlang faithful. The premise has been broadened since the Erlang Factory days of yore to welco...

In this post we’re going to see a handy technique to create and use stubs for your Elixir projects, leading to better tests, more maintainable code, and a lot of fun while using ETS, match specs, and macros. 15-20 minute read Let’s jump right in: Untestable code As an example, let’s say you have a m...

In the spirit of National Women’s History Month, we are publishing our third volume of our Tech Women of AdRoll Group series to celebrate and honor women across AdRoll Group (BI, Engineering, Product Management), and to acknowledge their diversity of backgrounds, viewpoints, and experiences. We had ...

We reduced our test run times by more than 50%, thus speeding up development and deployment considerably with the application of some generic tips that you can use in your system as well. 15-20 minute read As you can read in our previous blog post, at AdRoll we use Erlang/OTP extensively. In particu...

/**/ We slashed our DynamoDB costs by over 75% using Kinesis, DynamoDB streams, and Erlang/OTP (and now Elixir) to implement a global cache warming system. We present that system and two new open-source libraries for processing Kinesis and DynamoDB streams in a similar way using Elixir and Erlang. 1...

Over the past years, AdRoll has grown from a humble startup built around a single feature to a global marketing platform with a diverse suite of products. Along with the growth of the company, we have put a lot of work into building a solid infrastructure for user interface development. In this post...

Today, almost a year since the initial TrailDB open-source release, we are happy to announce the next major version of TrailDB, 0.6. The release is long overdue: this release is packed with major new features (and some minor bug fixes) that have been driven both by increasing internal use of TrailDB...

Last year we released TrailDB, a library we use extensively at AdRoll to efficiently store event data. Today we’re open sourcing trck, a query engine complementary to TrailDB that we use to analyze trillions of discrete events in TrailDBs every day. As you may remember, the TrailDB data schema is ve...

On the Data Science Engineering team, we are constantly working to improve the machine learning systems powering AdRoll’s products. We have recently started investigating Thompson sampling and Bayesian Factorization Machines as a way to ensure efficient exploration of the ad marketplace. In this pos...

tl;dr AdRoll’s real-time bidding system produces tens of billions events daily. We store these events in TrailDBs, a fast embedded database that we recently open-sourced. By leveraging a cool new feature in the Linux kernel, you can now query TrailDBs directly in Amazon S3 without having to store th...

Originally published on Medium on July 13, 2016. Update May 16th, 2017: Our style guide is now published at ux.adroll.com. You can read more about the latest updates on our UX blog. Q&A with AdRoll’s UX Designer on why we did it and what we learned. Hi! I’m Arya Srinivasan, a UX Researcher at AdRoll...

There is a terrific article in last week’s Sunday Times outlining Netflix’s role in changing the way we consume media. The central question of the piece is whether Netflix will dominate the world it has created. Nimble competitors like Amazon, Hulu, and the major studios (once threatened by streamin...

Introduction CODE: Debugging the Gender Gap is a documentary that exposes the dearth of American female and minority software engineers and explores the reasons for these gaps. CODE raises the question: “What would society gain from having more women and minorities code?” At AdRoll, we see the value...

tl;dr Today, we are open-sourcing TrailDB, a core library powering AdRoll. TrailDB makes it fast and fun to handle event data. Find it at traildb.io. Problem: Event Data Imagine that you have a large amount of event data that looks like this: 2016-05-02T22:48:38 user023 view features 2016-05-02T22:4...

Introduction Advertising is a competitive market. This probably won’t be the first time you hear something like that, but it’s absolutely true. For every move you make, you have to consider your competitors are getting a step closer to you. Speed and precision are key to the success of the business,...

Introduction If there is one thing that has been made abundantly clear over the last decade in tech, it’s that understanding your data is paramount to achieving your goals. Understandably, many startups have sprung up promising to aid every company and their employees with data analytics to fully op...