• Joined as one of the first 10 employees.
• Took the engineering team from 2 people to 300.
• Did an estimated 2,000+ interviews in the process of growing the team.
• Migrated the legacy tech stack to AWS, Postgres, Python, and microservices.
• Wrote code together with the team, building many critical components in Python and Node.js.
• Built and introduced much of the core foundation for the data platform.
• Introduced several machine learning models, including some with big impact on user acquisition and conversion.
• Was in charge of a 5-layer engineering organization.
• Managed and mentored engineers, promoted several people to managers and directors.
• Rolled out a career ladder along with a performance management system and compensation framework.
• Was actively involved in fundraising (series A to C), meeting investors, and presenting to the board.
• Ran the product team for seven months in 2019 and hired 10 product managers.

2011 – 2015 (New York City)

• Built up the core of the music recommendation system (80% of the current system is still my algorithms, according to people still at Spotify).
• Built an open sourced a data pipeline engine (Luigi) still used by Spotify and many other companies (Capital One, Foursquare, …).
• Built an open sourced a library for approximate nearest neighbors (Annoy) still used by Spotify and other companies (Uber, Instacart, …).
• Managed the music recommendation team, consisting of about 15 engineers.
• Invented and implemented many large scale machine learning algorithms, processing terabytes of data daily.
• Awarded three patents on recommender systems.
• Brought in a deep learning researcher in 2014 and prototyped a content-based music recommendation system.
• Tech lead for a larger group of engineers working on music recommendations, about 25 engineers in total.
• Spoke at several conferences and meetups.
• Left when Spotify was roughly 1,600 people.

2009 – 2011 (Stockholm)

• Joined in 2008 to work on my Master's Thesis when Spotify was roughly 30 people.
• Joined full-time in February 2009.
• Built and managed a small data team with three people reporting to me
• Reported directly to the CTO.
• Laid the groundwork for a our data strategy at Spotify.
• Ran the first A/B tests, price sensitivity analyses, any many other analyses.
• Built a system to simulate and quantify the ad inventory, and identified an opportunity to optimize ad delivery that saved several $MM/year.
• Worked closely with the business team and sent them analyses going directly to labels and investors.
• Left in Feb 2011, came back in Oct 2011 (after a brief stint at Graham Capital).

• One half of a team managing a $700M+ portfolio.
• Implemented high frequency trading strategies in C++ and C#, mostly for commodities and currency futures.
• Researched new strategies in Python and R.

• Took time off from university to work at Google for seven months.
• Worked on embedded systems for Google's infrastructure.
• Worked on large-scale data extraction for Google Maps.

• Spent six months at TU Berlin as an exchange student.
• Master's thesis ”Implementing a Scalable Music Recommender System“ was awarded best Master's Thesis in Sweden by Naturvetarna (a union).
• Represented university at the ACM international collegiate programming championship twice – in San Antonio 2006 and Tokyo 2007.
• Won the Nordic programming championship six times.

• Won the Swedish programming competition in 2002 and 2003.
• Won the Swedish physics competition in 2003.
• Placed number 5 in the Swedish mathematics competition in 2003.
• Represented Sweden in the International Olympiad in Informatics in Kenosha WI in 2003, placed 8 (gold medal).
• Represented Sweden in the International Mathematical Olympiad.