Senior Data Scientist / Machine Learning Engineer

AppNexus is an internet technology company that enables and optimizes the real-time sale and purchase of digital advertising. Our powerful, real-time decisioning platform supports core products that enable publishers to maximize yield; and marketers and agencies to harness data and machine learning to deliver intelligent and customized campaigns. Headquartered in New York City, AppNexus employs over 1000 professionals in offices spanning five continents.

Data Scientists are the creative thought leaders responsible for leveraging data to create automated systems for the efficient buying and selling of online advertisements. Our work drives algorithmic product innovation across the company. Data science projects underlie major features for both buyers and sellers on our platform as well as the marketplace design for our ad exchange itself, and it plays a starring role in finding and eliminating fraudulent ad traffic from our platform. We work closely with engineers, product managers, operations, and sometimes directly with clients to create novel features and systems. We love that our contributions further AppNexus’ position as a pioneer and thought-leader in digital advertising. We are committed to creating real value for publishers and marketers and believe that better advertising creates value for marketers, addresses the societal problem of helping publishers monetize content, and will create a better internet experience for all.

* Use machine learning techniques, visualizations, statistical analysis, etc. to gain insight into various data sets – some of which are readily available, and some of which you create and curate yourself (using technology such as Hadoop, Hive, Spark, Python, Scala) * Research, design, simulate and/or prototype new algorithmic product features based on business needs * Spend a significant amount of time collaborating with and providing hands-on mentorship to team members, both to build out specific projects and to continuously teach and learn new technology and techniques * Apply deep, creative, rigorous thinking to solve broad platform-wide technical and/or business problems * Communicate findings and solutions clearly to a variety of audiences, e.g. writing clear, comprehensive specs for engineers or explaining algorithmic concepts to product managers * Actively seek out a broad understanding of the AppNexus platform, product, and value proposition and align design efforts with that context * Work independently with minimal supervision but high accountability

**About your skills:** * Advanced degree in statistics, pure or applied mathematics, operations research, machine learning, engineering, or other highly quantitative field * Graduate degree and 2+ years’ experience (preferred) or Bachelor’s degree with 5 + years’ industry work experience doing machine learning or statistical modeling (Experience does not have to be in advertising/marketing but it does need to be from an industrial setting. Academic and research lab experience are not considered a substitute.) * Strong coding proficiency in at least one common scripting or compiled programming language (Python, Java, and/or Scala a plus) * Proven excellence at formulating, understanding, and solving complex, non-routine problems * Hands-on attitude toward problem-solving, including a willingness to dig into terabytes of data and quickly construct tools or models * Aptitude for diving into learning new theory and new technology * Strong written and verbal communication skills * Ability to work in a highly interactive, collaborative, fluid environment * Experience working with massive data sets and a production environment is preferred but not required * Experience with any of the following is a plus: generalized linear models, support vector machines, ensemble methods, tree based learning, deep learning, reinforcement learning, contextual bandits, Bayesian inference, clustering, convex optimization, causal inference, experimental design, control theory, kernel smoothing, generalized additive models **More about you:** * You are passionate about a culture of learning and teaching. You love challenging yourself to constantly improve, and sharing your knowledge to empower others * You like to take risks when looking for novel solutions to complex problems. If faced with roadblocks, you continue to reach higher to make greatness happen * You care about solving big, systemic problems. You look beyond the surface to understand root causes so that you can build long-term solutions for the whole ecosystem * You believe in not only serving customers, but also empowering them by providing knowledge and tools