Dejan Kostic (Full CV)

Dejan Kostic
Chair Professor of Internetworking at the KTH Royal Institute of Technology. Head of the Communication Systems Division and NSLAB. Associated with the Decisions, Networks and Analytics (DNA) Laboratory of RISE (Research Institutes of Sweden). Research interests: Distributed Systems, Computer Networks, Operating Systems, and Mobile Computing.


  • Dejan was awarded a 2-M EUR ERC Consolidator Grant 2018 and the project has started!
  • CacheDirector is in the news! TechXplore, Ericsson, KTH, KTH EECS.
  • Metron is in the news! ACM TechNews, PHYS.ORG, and KTH.
  • Open positions

    I am currently processing the applications for the two doctoral student positions in my recently-started European Research Council (ERC) Consolidator Project ULTRA (ERC is the flagship funding agency in Europe, and is funding this project with 2 M EUR). I am also again looking for an excellent postdoc to join this project (currently processing the applications).

    In this project we want to dramatically change the way Internet Services are constructed. We have already started to achieve significant gains in efficiency (about 7x), that come with substantial improvements in bandwidth (reaching and exceeding 100-Gbps with commodity server hardware) and latency (low and with low variance). As you can imagine, having services like this is crucial for the society. You can get a more detailed view of the type of work we do by looking at our Metron NSDI '18, Kurma SOCC '18, RSS++ CoNEXT '19, and Cheetah NSDI '20 papers. More info is available at the ULTRA project blog.

    I also have two doctoral students (licentiate) positions for my Time-Critical Clouds project (another large project, this time from the Swedish Foundation for Strategic Research). Licentiate is a degree halfway to the PhD in Sweden. This project started in 2016 and has accumulated publications in top venues, multiple PhD graduations, and several patents.


    Continuing my focus on low-latency networked systems, my biggest effort in the next five years will be on the 2018-2023 ERC Consolidator Project called ULTRA. In this single-PI, 2-Million EUR project, we want to dramatically change the way Internet Services are constructed. The project has started well, and in our upcoming SoCC 2018 paper, we present Kurma, our fast and accurate load balancer for geo-distributed storage systems. We have recently collaborated with Ericsson on our CacheDirector work published at EuroSys 2019. The work on Metron (NFV service chains at the true speed of the underlying hardware) has led to, and has inspired this project. Our most recent CoNEXT 2019 paper called RSS++shows how load-balancing with Receive Side Scaling (RSS) can be improved for large increases in efficiency. In our NSDI 2020 paper we have introduced Cheetah, a new load balancer for solving the difficult challenge of remembering which server is serving which connection, without the tradeoff between uniform load balancing and efficiency. In our USENIX ATC 2020 paper, we are reexamining Direct Cache Access (DCA) to optimize I/O intensive applications for multi-hundred-gigabit networks.

    A major focus area for my research group is on Time-Critical Clouds, a 2016-2021 project supported by SSF (the Swedish Foundation for Strategic Research) with 27 M SEK (~2.7 M EUR). This is a joint effort with the Decisions, Networks and Analytics (DNA) Laboratory of RISE.  Our first major contribution is a Eurosys 2017 paper (link to video and paper available here). In this work we reduce the tail latency in key-value stores by up to 1.9x by scheduling multiget requests more efficiently. Most recently we have shown how to run NFV service chains at the true speed of the underlying hardware in our upcoming NSDI '18 paper. In our EuroSys 2019 paper we have unlocked a performance-enhancing feature that existed in Intel processors for almost a decade.

    We have concluded the work on the PROPHET ERC project (2010-2016), in which we aimed to dramatically change the way networked systems are developed and deployed. For example, we improved the performance of geo-replicated storage systems using GeoPerf [SOCC '15]. We have successfully applied software verification techniques to increase the reliability of Software-Defined Networks (SDN). Some of our key contributions to testing of OpenFlow networks are NICE [NSDI'12] and SOFT [CoNEXT'12].  We have identified serious issues in the interplay between the control and data planes in OpenFlow switches [PAM '15], and proposed an approach for verifying rule installation [CoNEXT '14] as well as fine-grained dynamic monitoring of switch dataplanes [CoNEXT '15]. Extended versions of these contributions are now available as IEEE/ACM TON and Elsevier Computer Networks journal publications.

    We have wrapped up our work in the BEhavioral-BAsed Forwarding (BEBA) Horizon2020 project (2014-2017) that aimed to reshape Software-Defined Networks. Our contributions are described in George Katsikas' licentiate thesis, and involve deep understanding and performance optimization  of Network Functions Virtualization (NFV) service chains. Moreover, our recent work on Synthesized Network Functions, demonstrates high throughput with low predictable latency on a single commodity server thanks to its highly synthesized code and request dispatching. The overall project was recently highlighted by the EU comission.

    Recent Service

    ERC Starting Grant 2019 PE6 Panel member
    ERC Starting Grant 2017 PE6 Panel member

    TPC Co-chair of EuroSys 2020
    TPC Co-chair of ICDCS 2018 "Cloud Computing and Data Centers"
    TPC Co-chair of CoNEXT 2016

    TPC Member for NSDI '21
    TPC Member for NSDI '20
    TPC Member for SIGCOMM '19, USENIX ATC '19, NSDI '19
    TPC Member for Eurosys '18, EuroSys '17, CoNEXT '18, CoNEXT '17
    TPC Member for OSDI '16, CoNEXT '15, SoCC '15, NSDI'15

    Main Publications

    Please see the complete list of publications below for full author lists. (Auto-generated publication list from the DiVA repository is also available)

  • "Reexamining Direct Cache Access to Optimize I/O Intensive Applications for Multi-hundred-gigabit Networks", USENIX ATC 2020.
  • "A High-Speed Load-Balancer Design with Guaranteed Per-Connection-Consistency", NSDI 2020.
  • "RSS++: load and state-aware receive side scaling", CoNEXT 2019.
  • "Make the Most out of Last Level Cache in Intel Processors", EuroSys 2019.
  • "Fast and Accurate Load Balancing for Geo-Distributed Storage Systems", SoCC 2018.
  • "Metron: NFV Service Chains at the True Speed of the Underlying Hardware", NSDI 2018.
  • "Rein: Taming Tail Latency in Key-Value Stores via Multiget Scheduling", EuroSys 2017.
  • "Monocle: Dynamic, Fine-Grained Data Plane Monitoring", CoNEXT, 2015.
  • "The Nearest Replica Can Be Farther Than You Think", SOCC 2015
  • "What You Need to Know About SDN Flow Tables",  PAM 2015. 
  • "Providing Reliable FIB Update Acknowledgments in SDN", CoNEXT 2014.
  • "DeepDive: Transparently Identifying and Managing Performance Interference in Virtualized Environments", USENIX ATC 2013.
  • "A SOFT Way for OpenFlow Switch Interoperability Testing", CoNEXT 2012.
  • "A NICE Way to Test OpenFlow Applications", NSDI 2012.
  • "DejaVu: Accelerating Resource Allocation in Virtualized Environments", ASPLOS 2012.
  • "Identifying and Using Energy-Critical Paths", CoNEXT 2011.
  • "Insomnia in the Access (or How to Curb Access Network Related Energy Consumption)"SIGCOMM 2011.
  • "CrystalBall: Predicting and Preventing Inconsistencies in Deployed Distributed Systems", NSDI 2009.
  • "Staged Deployment in Mirage, an Integrated Software Upgrade Testing and Distribution System", SOSP 2007.
  • "Maintaining High Bandwidth under Dynamic Network Conditions", USENIX ATC 2005.
  • "FUSE: Lightweight Guaranteed Distributed Failure Notification", OSDI 2004.
  • "MACEDON: Methodology for Automatically Creating, Evaluating, and Designing Overlay Networks", NSDI 2004.
  • "Bullet: High Bandwidth Data Dissemination Using an Overlay Mesh", SOSP 2003.
  • "Using Random Subsets to Build Scalable Network Services", USITS 2003.
  • "Scalability and Accuracy in a Large-Scale Network Emulator", OSDI 2002.
  • Journal Publications

    Conference and Workshop Publications

    Current and past students

    I am advising several doctoral students at KTH:

    • Hamid Ghasemi (with Marco Chiesa as the co-advisor)
    • Alireza Farshin (with Gerald Q. Maguire Jr. as the co-advisor)
    • Waleed Reda (jointly advised with Marco Canini from KAUST)
    • Amir Roozbeh (with Gerald Q. Maguire Jr. as the co-advisor)
    • Akhila Rao, as secondary advisor from 2020 (industrial supervisor: Rebecca Steinert, main academic advisor: Magnus Boman)
    • Daniel Felipe Perez Ramirez, as main advisor from 2020 (industrial supervisor: Rebecca Steinert, academic co-advisor: Magnus Boman)

    Several of my students have already defended their PhDs:

    Some of my students at KTH have already defended their licentiate theses (a degree half-way to the doctoral degree in Sweden):

    Master projects from the following students were supervised and/or examined by me:

    • Farhad Zareafifi (with Marco Chiesa)
    • Henrik-Bjoerseth (with Marco Chiesa)
    • Muhammad Raheem (with Marco Chiesa)
    • thesis
    • Michail Xirouchakis  (with Alireza Farshin, as well as Georgios Katsikas and Rebecca Steinert at RISE)
    • Abdulrahman N Bilal Mohamed (with Kirill Bogdanov at KTH, 2018)
    • Khalid Omer Mahgoub Saied (with Kirill Bogdanov at KTH, 2018), thesis
    • Marcus Falgert (with Kirill Bogdanov at KTH, 2017), thesis
    • Marcel Enguehard (2015), thesis
    • Muhammad Zeeshan Abid (with Prof. Maguire at KTH, 2014), thesis

    Short biography

    Dejan Kostic obtained his Ph.D. in Computer Science at the Duke University. He spent the last two years of his studies and a brief stay as a postdoctoral scholar at the University of California, San Diego. He received his Master of Science degree in Computer Science from the University of Texas at Dallas, and his Bachelor of Science degree in Computer Engineering and Information Technology from the University of Belgrade (ETF), Serbia. From 2006 until 2012 he worked as a tenure-track Assistant Professor at the School of Computer and Communications Sciences at EPFL (Ecole Polytechnique Federale de Lausanne), Switzerland. In 2010, he received a European Research Council (ERC) Starting Investigator Award. From 2012 until June 2014, he worked at the IMDEA Networks Institute (Madrid, Spain) as a Research Associate Professor with tenure. He is a Professor of Internetworking at KTH since April 2014. In 2017, he received a European Research Council (ERC) Consolidator Award.


    d m k <at> k t h  <dot> s e

    Office phone# +46 8-790 42 65

    Mailing address

    Prof. Dejan Kostic
    KTH Kista
    Kistagangen 16
    164 40 Kista Sweden

    How to reach my office

    My office is 4401 in the Electrum Building on the KTH Kista campus, East side, entering from Elevator B on the 4th floor. Approximate coordinates (on Google Maps): 59.404850, 17.949922

    The best way to enter the Electrum building is from Kistagangen 16, 164 40 Kista, Sweden. Another, lower and harder-to-find, entrance is Isafjordsgatan 26, 164 40 Kista, Sweden.

    Getting here from the Arlanda Stockholm airport: a convenient way of getting to KTH Kista is by catching the suburban train from the Arlanda airport (but NOT the Arlanda express train!) to the Helenelund Train Station. You need to go to Arlanda C in Terminal 5 to board the train, and please expect to pay an airport supplement (85 SEK, I think but prices are gradually increasing). Example google maps itinerary from the airport (entrance to the Electrum building is a bit inconspicuous, through the sliding doors).

    Link to Google Maps

    Getting here from Stockholm downtown: taking the Blue Line metro toward Akalla and getting off at Kista T-Bana (next to the Galleria shopping mall) is the best option. Then you follow the signs for Kistamassan, going up the street called Kistagangen. You will reach KTH Kista very quickly (and will not get to Kistamassan itself).


    [not endorsed by KTH]
    I love taking Stockholm Photos. My larger portfolio is here: You can also follow me (dmkostic) on Instagram.