Speculative Recovery accepted at ATC '22!

Regular Sequential Consistency appeared at SOSP '21!

Dr. Khiem Ngo completed his PhD!

I co-lead the S* Network Systems (SNS) group with Mike Freedman and Amit Levy in the CS department at Princeton. I also co-advise two students with Ethan Katz-Bassett in an initiative to specialize distributed systems and networking for large applications deployed in datacenters.

I am interested in the theory, design, implementation, evaluation, and deployment of large-scale distributed systems. Keywords like big data, storage, consistency, geo-replication, consensus, concurrency control, and fault tolerance pique my interest.

One of my research directions looks at the tradeoffs between the guarantees and performance properties of distributed systems. Guarantees like consistency and transactional abilities make systems easier to reason about and program against. Performance properties like latency and throughput affect end user experience and the capital cost of systems. We're exploring what combinations of guarantees and performance are and aren't possible. RSS, PORT, and Gryff are our most recent work in this area, which also includes SNOW, Janus, Occult, Existential Consistency, Consistency Challenges, Rococo, Eiger, and COPS.

Another of my research directions looks at content delivery systems get photos, videos, and other content to the users of large-scale applications. LRB and TectonicFS are our most recent work in this area, which also includes the Streaming Video Engine, Chess, RIPQ and extensions from deploying it in practice at Facebook described in this blog post, f4 and a study of the Facebook photo caching stack.

Wyatt Lloyd

Associate Professor

Princeton University


All of this research is made possible by my fantastic students:

Current Students


Past Students


  • Khiem Ngo (2021) → Facebook Research Scientist
    • Dissertation: Tolerating Slowdowns in Replicated State Machines
  • Haonan Lu (USC 2019) → Princeton/MSR-NYC PostDoc → U Buffalo Assistant Professor
    • Dissertation: Performance-Optimal Read-Only Transactions


  • Jennifer Lam (2020) → Princeton PhD Program
  • Mohsin Alie (USC 2016) → Facebook
  • Abhinav Sharma (USC 2016) → Facebook
  • Jamie Tsaoe (USC 2016) → Google


  • Alan Kipkorir (2021) → Microsoft, Andrew Lin (2021), Colton Bishop (2021) → Google, Daniel Jubas (2021), Audrey Cheng (2020) → Berkeley PhD Program, John Suh (2020) → Robinhood, Parker Wild (2019) → Scholar in the Nation's Service Fellow, Noah Beattie-Moss (2019) → Facebook, Vignesh Rajendran (2019), Yousif Aldolaijan (USC), Sam Thomas (Cornell, USC visitor), Roberto Gonzalez (East LA College, USC visitor) → Cal Poly Pomona, Matt Burke (USC 2017) → Cornell PhD Program, Trevor Cai (USC 2017) → DeepMind/Alphabet, Brian Goodchilde (RU-Camden 2017, USC visitor) → Columbia PhD Program, Cary Jiang → Rice Undergrad, Chris Hodsdon (RU-Camden 2016, USC visitor) → Princeton PhD Program

Other Students