Data Mining

What is hardcore data science – in practice?


For example, for personalized recommendations, we have been working with learning to rank methods that learn individual rankings over item sets. Figure 1: Typical data science workflow, starting with raw data that is turned into features and fed into learning algorithms, resulting in a model that is applied on future data. This means that this pipeline is iterated and improved many times, trying out different features, different forms of preprocessing, different learning methods, or maybe even going back to the source and trying to add more data sources. Probably the main difference between production systems and data science systems is that production systems are real-time systems that are continuously running.

Laplace noising versus simulated out of sample methods (cross frames)


Please read on for my discussion of some of the limitations of the technique, and how we solve the problem for impact coding (also called "effects codes"), and a worked example in R.We define a nested model as any model where the results of a sub-model are used as inputs for a later model. And I now think such a theorem would actually have fairly unsatisfying statement as a one possible "bad real world data" situation violates the usual "no re-use" requirements of differential privacy; duplicated or related columns or variables break the Laplace noising technique. But library code needs to work in the limit (as you don't know ahead of time what users will throw at it) and there are a lot of mechanisms that do produce duplicate, near-duplicate, and related columns in data sources used for data science (one of the difference between data science and classical statistics is data science tends to apply machine learning techniques on very under-curated data sets). The results on our artificial "each column five times" data set are below: Notice that the Laplace noising technique test performances are significantly degraded (performance on held-out test usually being a better simulation of future model performance than performance on the training set).

Software Engineer in Machine Learning/


Your mission We are searching for great machine learning engineers to join the team responsible for: · Extending Criteo's large scale distributed machine learning library (e.g., implementing new distributed and scalable machine learning algorithms, improving their performance) · Building and improving prediction models for ad targeting; proving the business value of the changes and deploying them to production · Gathering and analyzing data, performing statistical modeling You'll have the opportunity to work on highly challenging problems with both engineering and scientific aspects; for example: · Click prediction:ÂHow do you accurately predict in less than a millisecond if the user will click on an ad? To qualify for this mission, you need: · MS degree in Computer Science or related quantitative field with 3 years of relevant experience or Ph.D degree in Computer Science or related quantitative field · Good understanding of the mathematical foundations behind machine learning algorithms · Great coding skills. Ability to write high performance production-grade code · Experience in one or more of the following areas: large-scale machine learning, recommender systems, or bandit algorithms ÂBonus points · Extensive experience in building and extending large scale production machine learning systems · Experience working with: Hadoop/Yarn, Spark · Experience in online advertising · Fluent in English About Criteo [CTRO] Criteo delivers personalized performance marketing at an extensive scale. A few figures: â 15 datacenters (8 with computing capacity 7 dedicated to network connectivity) Âacross US, EU, APAC â More than 15K servers, running a mix of Linux and Windows â One of the largest Hadoop clusters in Europe with close toÂ40PB of storage and 30.000 cores â â 30B HTTP requests and close to 3B unique banners displayed per day â Close to 1M HTTP requests per second handled during peak times â Â40Gbps of bandwidth, half of it through peering exchanges We recognize that engineering culture is key for building a world-class engineering organization.

Data-First Machine Learning - insideBIGDATA


In this special guest feature, Victor Amin, Data Scientist at SendGrid, advises that businesses implementing machine learning systems focus on data quality first and worry about algorithms later in order to ensure accuracy and reliability in production. At SendGrid, Victor builds machine learning models to predict engagement and detect abuse in a mailstream that handles over a billion emails per day. The training set (the data your machine learning system learns from) is the most important part of any machine learning system. Instead, build a system that samples production data, and have a mechanism for reliably labeling your sampled production data that isn't your machine learning model.