Databases and Information Systems



I'm a PhD candidate advised by Prof. Gerhard Weikum. I am broadly interested in applying well founded data mining and machine learning techniques to study social media and online communities data. I am especially passionate about applications with a focus on data science for social good.

Prior to joining MPI as a PhD student, I worked as a research assistant in Data Mining Group at Aalto University headed by Prof. Aristides Gionis, where my research was mainly concerned with knowledge discovery in large graphs - as well as investigate how these results can be used in a wide range of applications, including finding experts, recommendations, social network analysis. I earned my masters degree (honours) in Machine Learning and Data Mining at Aalto University (erstwhile Helsinki University of Technology) in Finland and bachelors degree (disctinction) in Computer Science at Osmania University in India.

Previously, I was a software engineer at Microsoft, India. In the 3 exciting years (2012-2015) at Microsoft, I worked in various roles revolving around data, including data mining, data analytics, business intelligence, search engine technology and have learnt various aspects of building large and scalable systems.


[Google Scholar]

  • Finding Topical Experts in Twitter via Query-Dependent Personalized PageRank, Preethi Lahoti, Gianmarco De Francisci Morales, and Aristides Gionis, Proceedings of the IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining ASONAM'17 [to appear]
  • Efficient Set Intersection Counting Algorithm for Text Similarity Measures, Preethi Lahoti, Patrick K. Nicholson, and Bilyana Taneva, Proceedings of the Ninteenth Workshop on Algorithm Engineering and Experiments ALENEX'17 [pdf]
  • Joint Non-negative Matrix Factorization for Learning Ideological Leaning on Twitter [under review]


  • Wearable Device for Facilitating Interaction between Individuals. Preethi Lahoti (Main Inventor), Patrick K. Nicholson, Deepak Ajwani, and Alessandra Sala. European Patent Filed on 08.12.2016. [patent pending]


  • (October 2015 – June 2017) Research Assistant, Data Mining Group, Aalto University:
    My research is mainly concerned with applying well founded data science techniques to study large graphs - as well as investigate how these results can be used in a wide range of applications, including finding experts, recommendations, social network analysis.
  • (June 2016 - August 2016) Research Intern, Data Analytics team, Nokia Bell Labs in Ireland:
    Contributed to a text mining and ML system; proposed an efficient approach to compute exact set intersection sizes; Implemented an end-to-end framework and performed experimental analysis on large text datasets (Wikipedia, Amazon and Enron)
  • (June 2012 – August 2015) Software Engineer, Microsoft, Hyderabad, India:
    Core Ranking & Relevance, Bing, Search Technology Center India: Contributed to the core ranking & relevance team responsible for shipping ranker to 40 + worldwide markets and languages; performed web log data mining and generated metadata for training pipeline. Built a dashboard (inception to execution) to analyze trends in web click data. The dashboard was used extensively by Bing Ranking & Relevance teams.
    Strategic Enterprise Service, Dynamics AX BI: Designed and Developed data warehouse, data processing, and reporting solution (financial and analytical reports) for Microsoft Consulting Services, on Dynamics AX data.
  • (June 2011 - August 2011) Software Development Intern, Microsoft, Hyderabad, India:
    Built an incident management tool to mine large scale backend services, analyze and summarize key statistics of data in real-time.


  • August 2017 - Started my PhD under the supervision of Prof. Gerhard Weikum at Max Planck Institute for Informatics, Germany
  • August 2017 - Graduated MSc in Technology (honours) in Computer Science from Aalto University in Helsinki!
  • June 2017 - My submission to 1st ACM Summer School got accepted. See you in Athens, Greece in July!
  • June 2017 - Successfully defended my MSc Thesis - "Learning Ideological Latent Space in Twitter" under the supervision of Prof. Aris Gionis at Aalto University School of Science, Finland.
  • May 2017 - Our paper "Finding topical experts in Twitter via query-dependent personalized PageRank" got accepted as a full paper at The IEEE/ACM International Conference on Social Networks Analysis and Mining 2017 in Sydney, Australia. Say hi if you around!
  • April 2017 - Received UCL Overseas Research Scholarship (ORS) three year research funding for completion of doctoral studies. (declined)
  • April 2017 - I will be hosting the 1st Virtual Open Day for Aalto University School of Science. Join us on YouTube Broadcast (update: watch day 1 recording here, will update day 2 recording soon!)
  • March 2017 - I will be starting my PhD under the supervision of Prof. Gerhard Weikum at Max Planck Institute for Informatics in August 2017. Wish me luck!
  • March 2017 - Received the International Max Planck Research School for Computer Science (IMPRS-CS) doctoral fellowship , a three year research funding for completion of doctoral studies. (accepted)
  • January 2017 - I will be presenting our paper "Efficient Set Intersection Counting Algorithm for Text Similarity Measures" at ALENEX track of SODA 2017 in Barcelona, Spain. Join me if you are around!
  • December 2016 - Received The ACM-SIAM Symposium on Discrete Algorithms (SODA 2017) travel grant!
  • December 2016 - I will be giving a talk "Career and Study in Finland" at Vasavi College of Engineering, Hyderabad, India on 26th December. Update: We received excellent response from the students. About 80 students joined the session!

Personal Trivia

I love cooking, travelling and hiking! I like to dream about the day when I will have a travelling food truck - worlds best moving street food restaurant, you never know where I might pop up! Until then, I work on my passions in increments. My next travel goal is 30/30 (visit 30 countries by the time I am 30).
Current statistics: visited 14 countries across 4 continents, lived and worked in 4 of them.