Big Data Spain is an annual conference on Big Data and related topics held in the suburbs of Madrid. This year’s, i.e. third, edition has so far been the biggest; it has attracted more than 500 guests and various speakers including Big Data celebrities like Paco Nathan of Databricks. During two days of the conference, guests could attend many keynotes, speeches and workshops and learn about variuos products, services and specific use-cases, in both English and Spanish. Allegro was represented by two employees with a presentation on Hadoop pitfalls and gotchas.