MoSQL: When SQL meets NoSQL

Short Form


I will present MoSQL, an open-source tool for mirroring data from MongoDB to PostgreSQL. I will argue for mixed SQL/NoSQL environments, and talk about my experience using MoSQL to expand the availability of easy access to data internally at Stripe.


NoSQL data store solutions offer many advantages, and are an increasing popular solution to database needs in web applications and otherwise. However, moving away from SQL comes at a cost, especially in terms of ad-hoc data access for analytics, reporting, or exploration, and in terms of ease-of-access of data by non-engineers.

I will present MoSQL, an open-source tool for live-replicating MongoDB data into PostgreSQL. I’ll argue in favor of this approach — coexisting SQL and NoSQL — for managing data, and I’ll talk about my experiences using this tool to enable direct access to data for exploration and analysis by non-engineers at Stripe.

Speaking experience

I've presented at DEFCON and BlackHat, and was invited back to repeat the talk at Black Hat UAE. Talk video: and slides:

I've also given various smaller-scale presentations, teaching topics such as git, scheme, unicode, and computer security in association with various groups at MIT.


  • Img 8491 2158299298 o


    Nelson Elhage is a systems hacker at Stripe, where he’s building infrastructure to help power the future of payment systems online.

    He’s developed and released several open-source tools, including MoSQL, a system for live-replicating MongoDB into PostgreSQL, and livegrep, a tool for super-fast interactive searching of large repositories of source code, and is an on-and-off contributor to numerous other projects.