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Juba Ziani

@jubaz.bsky.social
656 followers 476 following 95 posts

Assistant professor at Georgia Tech in ISyE. I do mechanism design, differential privacy, fairness, and learning theory, mostly. Postdoc @Penn; Ph.D. @Caltech; MSc @Columbia and @Supélec. He/him.

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Juba Ziani @jubaz.bsky.social · 16/07/2026
Crossroads of AI and AC-less society
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Juba Ziani @jubaz.bsky.social · 21/06/2026
So it's the Law of Totally what you'd Expect?
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Juba Ziani @jubaz.bsky.social · 13/06/2026
A bound? Is it tight?
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Juba Ziani @jubaz.bsky.social · 13/06/2026
Oh. Oooooooh!
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Juba Ziani @jubaz.bsky.social · 13/06/2026
Is anyone still alive here? Outside of @ccanonne.github.io I mean
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Juba Ziani @jubaz.bsky.social · 09/04/2026
Why can't you work better in teams?
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Juba Ziani @jubaz.bsky.social · 08/04/2026
You now excel at at least one thing
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Juba Ziani @jubaz.bsky.social · 28/03/2026
What's "thinking"? I feel like I used to know what it meant a long time ago.
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ACM SIGecom @acmsigecom.bsky.social · 20/02/2026
This Wednesday! Don't forget to register! Featuring Keynotes and Discussants (11:00am-1:00pm ET) @djweitzner.bsky.social (MIT) with Kobbi Nissim (Georgetown), Katrina Ligett (HUJI) with Talia Gillis (Columbia)
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ACM SIGecom @acmsigecom.bsky.social · 20/02/2026
Wrapping up with a Fireside Chat (4:15-4:45pm ET) with @jasonhartline.bsky.social (Northwestern) and Nicole Immorlica (Yale and MSR). Plus lots of social events on Gather throughout the day! Join us, but start by registering!
forms.gle
Registration: SIGecom Winter Meeting 2026
February 25, 2026 on Virtual Chair. Event website
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Amin Rahimian @rahimian.bsky.social · 08/12/2025
WINE tutorial on Differential Privacy for Strategic Information Sharing and Learning today at 2 pm EST, in person and on zoom, link: sites.google.com/pitt.edu/win... with @jubaz.bsky.social @papachristoumarios.bsky.social and @yuxin-pitt.bsky.social
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Juba Ziani @jubaz.bsky.social · 02/12/2025
The issue actually seems fixed on my end! Thanks again :)
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Juba Ziani @jubaz.bsky.social · 01/12/2025
Thank you!
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Juba Ziani @jubaz.bsky.social · 01/12/2025
I am also unable to submit recommendation letters, also getting a "permission denied"
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Reposted by Juba Ziani
TCS+ @tcsplus.bsky.social · 25/11/2025
📢 Our last TCS+ talk of the season will be Wed, Dec 3 (10am PT, 1pm ET, 19:00 CET): Natalie Collina (@ncollina.bsky.social), from UPenn, will tell us about "Swap regret and correlated equilibria beyond normal-form games"! RSVP to receive the link (one day before the talk): forms.gle/utLgSxLpqvpx...
forms.gle
TCS+ RSVP: Natalie Collina (2025/12/03)
Title: Swap regret and correlated equilibria beyond normal-form games
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Juba Ziani @jubaz.bsky.social · 22/10/2025
Hire Natalie right now! She's amazing
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Juba Ziani @jubaz.bsky.social · 22/10/2025
Congrats to @epsilonrational.bsky.social @ncollina.bsky.social @aaroth.bsky.social on being featured in quanta! (Also do check out the paper, also involving Sampath Kannan and me that the piece is based on here: arxiv.org/abs/2409.03956)
arxiv.org
Algorithmic Collusion Without Threats
There has been substantial recent concern that pricing algorithms might learn to ``collude.'' Supra-competitive prices can emerge as a Nash equilibrium of repeated pricing games, in which sellers play...
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Juba Ziani @jubaz.bsky.social · 15/10/2025
Hi everyone, The TOC4Fairness seminar series are restarted! Our next speaker, this *Monday* October 20th (1pm est, 10am est) is Lalitha Sankar from ASU. More info about her talk here! toc4fairness.org/toc4fairness... If you need the zoom link/mailing list access, please DM me
toc4fairness.org
TOC4Fairness Seminar – Lalitha Sankar
Date: Monday, October 20th; 10:00 am – 11:00 am Pacific Time Location: Zoom meeting
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Juba Ziani @jubaz.bsky.social · 19/09/2025
Hello, this is now accepted at Neurips 2025! Come check out our poster in December :)
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Juba Ziani @jubaz.bsky.social · 19/09/2025
Thanks to Yunzong Xu and Bhaskar Ray Chaudhuri for the invite!
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Juba Ziani @jubaz.bsky.social · 19/09/2025
Can't recommend the Allerton conference at UIUC enough! Went for the first time this year and really enjoyed the smaller scale, being able to talk to so many great researchers, the community, and the great talks! Definitely got quite a bit out of that and a million new ideas
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Clément Canonne @ccanonne.github.io · 25/08/2025
New differential #privacy textbook in town: "DP in Artificial Intelligence: From Theory to Practice", by @nandofioretto.bsky.social and @vanhentenryck.bsky.social. Open access, w/ chapters by @jubaz.bsky.social, @grahamrc.bsky.social, and @stein.ke! www.nowpublishers.com/article/Book...
Front cover: Differential Privacy in Artificial Intelligence: From Theory to Practice, now Publishers
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Juba Ziani @jubaz.bsky.social · 22/08/2025
It's also the tone of the PC. They keep changing the process mid-day, shortening the timeline for ACs, and instead of acknowledging this, blaming the ACs and sending repeatedly threatening emails for ha being one day late on a task that we had a half the original assigned time for
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Juba Ziani @jubaz.bsky.social · 11/08/2025
Check out our @let-all.com blog post on strategic classification and around recent work with Valia and @charapod.bsky.social!
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Juba Ziani @jubaz.bsky.social · 19/07/2025
The tl;dr is that balanced/fair algorithms do not necessarily comes at a cost. When you take incentives around data and network effects into account, fairness (here, through representativeness) can come at no cost. And the paper that started it all: arxiv.org/abs/2501.19294
nsf.gov
NSF Award Search: Award # 2504990
Collaborative Research: III: Medium: Incentives and interventions for robust networked data exchange
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Juba Ziani @jubaz.bsky.social · 19/07/2025
Excited to announce that I just got another NSF grant this week! This collaborative with Prof. Augustin Chaintreau at Columbia University. More info here: www.nsf.gov/awardsearch/...
nsf.gov
NSF Award Search: Award # 2504990
Collaborative Research: III: Medium: Incentives and interventions for robust networked data exchange
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Clément Canonne @ccanonne.github.io · 08/07/2025
Pretty stoked to announce that I won't be presenting my paper at #FOCS2025: but one of my talented coauthors will have to come here 🌏 to do so! "Instance-Optimal Uniformity Testing and Tracking," with Guy Blanc (Stanford) and Erik Waingarten (UPenn). (arXiv coming soon!)
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Juba Ziani @jubaz.bsky.social · 13/06/2025
The cointreau or the apricot? I found that every time I put cointreau in a cocktail, I should have used half.
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Juba Ziani @jubaz.bsky.social · 13/06/2025
How did it turn out
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Krishna Acharya @kvachai.bsky.social · 09/06/2025
1/8 Happy to share that our paper GLoSS: Generative Language Models with Semantic Search for Sequential Recommendation is accepted at the KDD OARS workshop! 🎉 Paper, code: github.com/krishnachary... This is joint work with my wonderful collaborators @apetrov.bsky.social and @jubaz.bsky.social !
github.com
GitHub - krishnacharya/GLoSS: GLoSS: Generative Language Models with Semantic Search for Sequential Recommendation
GLoSS: Generative Language Models with Semantic Search for Sequential Recommendation - krishnacharya/GLoSS
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ProPublica @propublica.org · 11/04/2025
THREAD: Under a new law, thousands of prisoners in Louisiana have been cut off from ever getting a chance at parole. Why? Because an algorithm said so. 1/
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Juba Ziani @jubaz.bsky.social · 01/05/2025
Hello, I'm off Twitter forever! This is the main place to find me now :)
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Juba Ziani @jubaz.bsky.social · 07/04/2025
Hi everyone! First, wanted to let you all know that the amazing @charapod.bsky.social is on Bluesky! Please make sure to follow her :) Second, she wrote a really cool survey about the state of strategic classification that you should definitely read: www.sigecom.org/exchanges/vo...
sigecom.org
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Juba Ziani @jubaz.bsky.social · 10/03/2025
With this work, we aim to add nuance to the discourse that decentralization on its own may not be the solution---rather, centralized decision-making should be more fine-grained to go beyond naive metrics, and understanding diversity of backgrounds/signals that make up qualified candidates.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
This creates unfairness where *equally qualified* candidates are treated disparately based on, for example, how recognizable their alma matter is.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
The easy way out here is spectacularly bad: hire candidates that they fully understand/have more information about, rather than candidates that are riskier (i.e., a top student from a small, not well-known high school).
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Juba Ziani @jubaz.bsky.social · 10/03/2025
Our main insight is as follows: while decentralization is useful to score candidates beyond just generic characteristics/take into account how successful they are expected to be for a specific team, our mathematical model shows that such decentralized designer will always take the easy way out.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
In stage 2, decentralized entities (professors in a university or specific teams in a company) make admissions/hiring decisions based not only on "quality" (again, which is imperfectly perceived), but also how their specific attributes contribute to the specific team they aim to join.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
We propose a mathematical model of 2-stage admission/hiring that questions this conventional wisdom. In stage 1, a centralized designer makes initial hiring/admissions decisions based solely on a candidate's perceived "quality" (a noisy signal of their competences).
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Juba Ziani @jubaz.bsky.social · 10/03/2025
In particular, applicants that look atypical may be ignored (e.g., top and highly qualified applicants from lesser known schools, or applicants with less access to extracurricular activities to add to their CV).
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Juba Ziani @jubaz.bsky.social · 10/03/2025
The classical wisdom of the crowd is that centralization is bad: centralization tends to rely on generic decision-making rules and AI tools that optimize for historical admissions criteria without considering the diversity of applicant backgrounds.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
Here, we study the impact of centralization vs decentralization in hiring and admissions.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
A last work I wanted to talk about (I promise I will stop spamming after this) with my student Diptangshu Sen and collaborator Ben Fish is here: www.arxiv.org/abs/2502.07792
arxiv.org
Centralization vs Decentralization in Hiring and Admissions
There is a range of ways to organize hiring and admissions in higher education, as in many domains, ranging from very centralized processes where a single person makes final decisions to very decentra...
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Juba Ziani @jubaz.bsky.social · 10/03/2025
Interestingly, and likely because of the special structure of our game, we see that very few samples are needed each time step for the dynamics to converge properly.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
We derive results (theoretically and experimentally) both in the full-information setting where all players fully now the distribution of customers, and in the in-sample setting where this must be derived from samples.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
One thing that we lose, compared to the original performative prediction paper, is *uniqueness*. Our game has several equilibria, some symmetric, some asymmetric, some pure, some mixed. We show that the equilibrium we converge to heavily depends on how the algorithm is initialized
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Juba Ziani @jubaz.bsky.social · 10/03/2025
This may be surprising---we would expect no-regret dynamics by both players to converge to a coarse correlated equilibrium, but we in fact show convergence to a significantly smaller set of equilibria
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Juba Ziani @jubaz.bsky.social · 10/03/2025
Our setting, being a Bertrand-type model, clearly does not enjoy nice insensitivity properties. Yet, despite this, we are able to show experimentally and theoretically convergence to a stable solution. Further, this stable solution happens to be one of the Nash equilibria of our game.
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Juba Ziani @jubaz.bsky.social · 10/03/2025
We aim to study the convergence of simple no-regret dynamics (here, each player playing exponential weights) in this setting
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Juba Ziani @jubaz.bsky.social · 10/03/2025
Finally getting to our work: we propose a simple model of 2-player competition for mortgages. We consider two firms that can set two parameters: the minimum credit score they require, and the mortgage rate.
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