I am a PhD student at the MPI-SWS Operating Systems Group, where I am advised by Antoine Kaufmann and investigate TCP kernel bypass and ways to speed up packet processing in virtualized environments. I also worked with Jonathan Mace with whom I explored reinforcement learning techniques to improve scheduling of requests for machine learning inference.

Previously, I was a MSc student in the Systopia Lab at the University of British Columbia, under the supervision of Ivan Beschastnikh and Aline Talhouk. At UBC my interests revolved around building secure and privacy-preserving distributed systems, where I collaborated closely with Mathias Lécuyer on exploring novel ways for DP systems to conserve their privacy budget.


🎓 PhD: Computer Science - 2021-Present

Max Planck Institute for Software Systems

🎓 MSc: Computer Science - 2019-2021

University of British Columbia

🎓 BA: Major, Computer Science | Minor, Philosophy - 2015-2019

University of British Columbia



Virtuoso is a TCP acceleration service for virtualized environments targeted at applications that require low latency and high throughput. Virtuoso runs as a service alongside the host and provides a fast-path for common send and receive operations that reduces the virtualization overheads incurred by the hypervisor and guest operating system. The network stack is shared between multiple VMs, thus increasing the utilization of the underlying resources. Virtuoso only has to provision for peak aggregate utilization, instead of the sum of the peak utilizations of each VM. Furthermore, Virtuoso ensures performance isolation in a shared stack by doing fine-grained scheduling that reduces inter-VM interference of running applications.


LEAP is a large-scale federated and privacy preserving evaluation and analysis platform. LEAP allows users to analyze data distributed across multiple institutions in a private and secure manner, without leaking sensitive user information. This is achieved through an infrastructure that maintains privacy by design and brings the computation to the data, instead of bringing the data to the computation.

User queries are propagated to different sites, where each site gives back the result of running the computation on the local data, with carefully added noise to guarantee differential privacy. The results are returned to the LEAP infrastructure in the cloud, where they are aggregated and sent to the end-user. The infrastructure also keeps track of the privacy loss from each query, safeguarding against information leakage from repeated queries.


Performance issues in cloud systems are hard to debug. Distributed tracing is a widely adopted approach that gives engineers visibility into cloud systems. Existing tracing tools support the analysis of a single request and are most useful for debugging correctness issues. However, diagnosing performance issues in the processing of a request requires comparing the performance statistics of the offending request with those of normal requests. This processing depends on trace aggregation, which is not supported by existing tracing tools.

TraVista is a tool designed for debugging latency issues in cloud systems. It helps developers identify the correct aggregate data for diagnosis and effectively visualizes the data, so that performance issues can be identified. Our tool aggregates four types of data: metrics, logs, temporal and structural data and uses an array of visualization techniques to reduce cognitive load and help developers more efficiently find issues with their systems.


Developing kernel file systems presents challenges due to the complexity of the environment. The inflexibility of this environment discourages exploration of alternatives; most file systems research is focused on improving the storage management aspects, rather than the application facing interfaces. While userspace file systems mitigate the development complexity, they do so with a significant performance penalty and little flexibility for exploring novel access models. Finesse addresses these two concerns by adding both a client side library and a FUSE file system library. Finesse implements a kernel bypass mechanism for key operations and enables making new interfaces available to applications, thus improving performance while balancing compatibility against flexibility.


Federated Learning is the current state of the art in supporting secure multi-party machine learning: data is maintained on the owner’s device and the updates to the model are aggregated through a secure protocol. However, this process assumes a trusted centralized infrastructure for coordination, and clients must trust that the central service does not use the byproducts of client data. In addition to this, a group of malicious clients could also harm the performance of the model by carrying out a poisoning attack. Biscotti is a fully decentralized peer to peer (P2P) approach to multi-party ML, which uses blockchain and cryptographic primitives to coordinate a privacy-preserving ML process between peering clients.


Research Assistant - UBC

May 2019 - August 2019
  • Developed a data analytics platform to perform distributed queries in hospitals and research centres

  • Used differentially private techniques to prevent information leakage from distributed queries

  • Presented the work on seminars at UBC and BC Cancer Research Centre

Software Developer - Thrive Health

May 2018 - August 2018
  • Worked on program to triage patients before surgery

  • Used React and Redux to build webapp frontend

  • Developed a media transcoder to convert videos into mp4 and to extract thumbnail from pictures

  • Used AWS lambdas and SQS to scale deployment of media transcoder


Graduate Teaching Assistant - UBC

January 2020 - May 2020
  • Helped students with topics such as distributed system design, replication, and failure recovery

  • Responded student questions on an online discussion board

  • Coordinated grading and assignment ideas with the course team

Undergraduate Teaching Assistant - UBC

September 2018 - December 2018
  • Conducted tutorials on network infrastructure, packet routing, and communication protocols

  • Held office hours to help students with assignments and lecture material

  • Graded assignments and quizzes


Virtuoso: High Resource Utilization and μs-scale Performance Isolation in a Shared Virtual Machine TCP Network Stack

Under submission, 23

Matheus Stolet, Liam Arzola, Simon Peter, Antoine Kaufmann

The Odd One Out: Energy is not like Other Metrics

HotCarbon 22

Vaastv Anand, Zhiqiang Xie, Matheus Stolet, Roberta De Viti, Thomas Davidson, Reyhaneh Karimipour, Jonathan Mace


Virtuoso TCP Stack: Squashing Isolation and Resource Efficiency Tradeoffs in Virtualized Environments

1st Place SOSP 23 Student Research Competition

Matheus Stolet

Finesse: Kernel Bypass for File Systems

European Conference on Computer Systems (EuroSys’ 20)

Matheus Stolet and Tony Mason