The whole data architecture at 500px is mainly based on two tools: Redshift – for data storage, and Periscope – for analytics, reporting, and visualization. From a customer-facing side, the company’s web and mobile apps run on top of a few API servers, backed by several databases – mostly MySQL. Data in these DBs is then processed through a Luigi ETL, before storing it to S3 and Redshift. Splunk here does a great job in querying and summarizing text-based logs. Periscope Data is responsible for building data insights and sharing them across different teams in the company. All in all, this infrastructure supports around 60 people distributed across a couple of teams within the company, as of 2015.

Data-related technologies used in 500px.
Fig: Some of the data-related technologies used in 500px. 
Source: https://medium.com/@samson_hu/building-analytics-at-500px-92e9a7005c83