Machine learning requires a lot of data and most of the time you, as the developer of an algorithm, will not have the time to synthesize or obtain good data. However, you are in luck. Kaggle does that for you. Kaggle is a website where companies host several machine learning problems and they provide training and test data to test your algorithm. Some competitions are linked with employment. So if your model stands out, you stand a chance to interview with the company that hosted the competition. Here is a short list of companies that are using kaggle for their data science/machine learning problems:
The next section gets you started with a kaggle competition; getting the data and solving it.