In summary it was shown that in the context of big data and complex models to describe relations in the data there are many challenges to overcome. The choice of model, on what metric to optimize the model -- i.e. the cost function -- and how to perform the optimization are all crucial choices that can have a significant impact on the performance of the model. The use of regularization techniques can help to prevent overfitting and improve the generalization performance of the model. The number of degrees of freedom in the model directly influcences the bias-variance trade-off and only with a good balance between the two can a model perform well on unseen data. Finally, the choice of optimization algorithm can have a significant impact on the computational cost of the models training process. Using good optimization algorithms can help to speed up the convergence of the models parameters. Combining this with other innovative techniques such as stochastic gradient descent can help to further reduce the computational cost of training complex models on large datasets.