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Citigroup technology stack
Stylus Workspaces, Arc agents, Devin and the cloud.

Last updated Oct 16, 2026 · 19 sources cited

What technology stack does Citi use for AI?

Citi's AI runs on a stack built during Jane Fraser's transformation, which she said on October 13, 2026 'modernized our core technology platform giving us the foundation we need to implement AI firm wide'. Employees use Citi Assist and Stylus Workspaces, rolled out from late 2024 and running on Google's Gemini and Anthropic's Claude; agentic features were piloted with 5,000 users in September 2025. Arc, launched April 30, 2026, is the platform for building agents that are 'monitored, auditable and governed', and every agent at Citi goes through one central framework built in 2024. Engineers use Citi Squad and GitHub Copilot for coding assistance, and Cognition's Devin, now used by 14,000 engineers, remapped more than 30 years of legacy code; AI code reviews free about 100,000 hours a week. Google Cloud is the main cloud partner under an October 2024 multi-year agreement that includes Vertex AI. Business platforms such as Velocity, Olympus and Stylus in Markets and the Xing risk platform are, per the investor day, foundational to Citi's technology edge, and Services invests over $2 billion a year in platforms including data and AI. Citi retired 548 applications in 2025.[1][2][3][4][5][6][7][8][9][10][11][12]

Data as of Oct 16, 2026 · Citi profile updated Oct 13, 2026 · 19 sources cited on this page · 140 banks profiled on this site · Markdown

What are the layers of Citi's AI technology stack?

LayerWhat Citi usesDetailDate
Employee assistantsCiti Assist and Stylus WorkspacesRolled out to 150,000 staff by April 2025; more than 180,000 people and 87%-plus adoption by September 20262024-2026[2][8]
ModelsGoogle Gemini and Anthropic ClaudeBoth run inside Stylus Workspaces, per a Citi spokespersonSeptember 2025[4]
Agent platformArcDevelopers build agents for well-defined use cases first; 'Every agent will be monitored, auditable and governed'April 30, 2026[5][13]
Agent governanceCentral agent frameworkOne framework, built in 2024, every agent passes through for visibility and traceabilityJune 2026[6]
Coding assistantsCiti Squad, GitHub CopilotCiti Squad to about 9,000 developers by April 2025; 740,000 automated code reviews by July 20252024-2025[2][7]
Coding agentsCognition Devin14,000 engineers; remapped 30-plus years of legacy code; reads only internal repositories, humans approve changesJuly 2025-October 2026[7][8][1]
Cloud and ML platformGoogle Cloud, Vertex AIWorkloads migrating to Google Cloud; Vertex AI for developer toolkits, document processing and servicingOctober 2024[10]
Markets platformsVelocity, Olympus, Stylus, XingFoundational to Citi's technology edge; Xing is a scalable risk-management platformMay 2026[11][9]
Legacy retirementApplication decommissioning548 applications retired in 2025; AI used to retire old software faster2025-2026[12][14]

Does Citi build or buy its AI, and how does it control suppliers' AI?

Citi builds the employee platforms and the agent layer in house (Stylus, Assist, Arc) and buys models and coding agents from Google, Anthropic and Cognition. Fraser said Devin makes it 'much more efficient for us to do the work in house', insourcing work that cut technology vendor spend by 30% year on year.[8][1]

Suppliers face tight AI rules. Citi's September 2026 supplier requirements bar vendors and subcontractors from using AI or machine learning, including generative and agentic AI, in products, services or any work that may expose Citi information unless agreed in the contract; breach is material. Suppliers may not use Citi information to train AI without written approval and must help with algorithm audits if a regulator asks.[15]

On security, Fraser said Citi deploys frontier models 'securely through a structured harness across our entire perimeter' to find and fix vulnerabilities at speed. Not disclosed: Citi's GPU capacity, its model-hosting split between cloud and own data centers, or a technology budget broken out for AI.[1]

What does the Citi profile record on this topic?

The rows below are the entries of the Citi AI strategy profile that bear on this page, as of Oct 13, 2026; the profile holds the full record of 40 dated moves, 20 use cases and 59 sources.

Use caseWhat the record showsStatusSource
Stylus Workspaces and engineering agentsFirm-wide assistant; agentic AI for 10,000-plus engineers on legacy remapping.In production[16]
Google Cloud, DeepMind and Cognition partnershipsCiti Sky built on Gemini Enterprise Agent Platform and DeepMind avatar technology; Cognition's Devin coding agent used to remap legacy code; relationships with Anthropic, OpenAI, Google and Microsoft.In production[17][8]
Devin coding agents and AI code reviewCognition's Devin rolled out to Citi's 40,000 developers from July 2025 for patches, upgrades and language rewrites; agents read only internal repositories and humans approve every change. Citi says AI-assisted code reviews free about 100,000 hours of capacity a week.In production[7][9]
DateMoveDetailSource
Sep 22, 2026Group Head of AI profile: 65 million interactionsThe bank says Stylus Workspaces has reached more than 180,000 people with 87%-plus adoption, AI cut US client-onboarding document review from about an hour to 15 minutes, and Citi takes part in Anthropic's Project Glasswing.[8]
Jun 16, 2026One way to deploy an agentMarkets CIO Nikhil Joshi says every agent at Citi goes through one central framework, built in 2024, for visibility and traceability.[6]
May 1, 2026Arc agent platform launchedA platform for building and scaling AI agents, first for developers' internal use cases, then in everyday workflows; 'for the first time, we can deploy embedded AI agents at enterprise scale', said then-CTO David Griffiths.[13]
Sep 22, 2025Stylus Workspaces goes agenticA 5,000-user pilot of agentic AI inside Stylus Workspaces, running on Gemini and Claude models; Griffiths on headcount: 'Does it mean that we need less people? I don't know.'[4][18]
Sep 9, 2025Shobhit Varshney named head of AIFormer IBM head of data and AI named in a memo from COO Anand Selva; he reports to the COO and works alongside CTO David Griffiths. Stylus, Workspaces and Assist had reached 175,000 employees.[19]
Jul 14, 2025Devin coding agents for 40,000 developersCiti begins rolling out Cognition's Devin to automate software patches, upgrades and language rewrites; agents work only from internal repositories and humans approve all output. Citi Squad had completed 740,000 automated code reviews, about 100,000 hours a week saved.[7]
Apr 9, 2025Assist and Stylus reach 150,000 staffCTO David Griffiths: Citi Assist and Citi Stylus rolled out to 150,000 employees; Citi Squad, the coding tool, to about 9,000 developers; a new Stylus version goes to 10,000 early adopters, shaped by feedback from AI 'accelerators'.[2]
Oct 28, 2024Google Cloud multi-year agreementCiti will migrate workloads to Google Cloud and use the Vertex AI platform for generative AI in developer toolkits, document processing and customer servicing; Tim Ryan: Google Cloud 'opens up a whole new frontier'.[10]
Oct 1, 2024Citi Stylus Workspaces rolled outAdoption starts in the single digits; the champions programme is built to change that.[3]

What is Citi Stylus Workspaces?

Stylus Workspaces is Citi's most widely available AI tool for staff, rolled out from late 2024. It runs on Google's Gemini and Anthropic's Claude models, added agentic features in a 5,000-user pilot in September 2025, and had reached more than 180,000 people with over 87% adoption by September 2026.

What cloud does Citi use for AI?

Google Cloud is Citi's main announced cloud partner. A multi-year agreement from October 2024 moves workloads to Google Cloud and supplies the Vertex AI platform for developer toolkits, document processing and customer servicing; Citi Sky is built on Google's Gemini Enterprise Agent Platform.

How does Citi use AI in software engineering?

Citi Squad and GitHub Copilot assist developers, AI code reviews free about 100,000 hours of engineering capacity a week, and Cognition's Devin is the main agentic coding tool, used by 14,000 engineers by October 2026 and credited with remapping more than 30 years of legacy code.

Can Citi's suppliers use AI?

Only with Citi's agreement. The September 2026 Citi Requirements for Suppliers prohibit vendors from using AI or machine learning, including generative and agentic AI, in Citi work or in ways that may expose Citi information unless agreed in the contract, and bar training AI on Citi data without written approval.

  1. Citi (C) Q3 2026 Earnings Call Transcript
    The Motley Fool (earnings call transcript) · Oct 13, 2026
  2. How Citi's CTO is rolling out new gen AI productivity tools to more employees across the globe
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  3. The AI Superfans Companies Count On to Convert the Skeptics
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  4. Citi deploys agentic tools to in-house AI platform
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  5. Introducing AI Agents: The Next Phase in Our AI Journey
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  6. Citi, Ford, and Experian share their strategies for scaling AI agents
    Fortune · Jun 16, 2026
  7. Citi is rolling out agentic AI to its 40,000 developers
    American Banker · Jul 14, 2025
  8. A Competitive Differentiator: David Griffiths on Building the World's Most AI-empowered Financial Institution
    Citigroup · Sep 22, 2026
  9. Citi 2026 Investor Day Transcript - Consolidated
    Citigroup · May 7, 2026
  10. Citi and Google Cloud Announce Strategic Agreement to Modernize Citi's Technology Infrastructure and Drive Innovation
    PR Newswire · Oct 28, 2024
  11. Citi 2026 Investor Day - Discussion Guide
    Citigroup · May 7, 2026
  12. Citigroup Inc. Annual Report on Form 10-K for the year ended December 31, 2025
    Citigroup (SEC filings) · Feb 20, 2026
  13. Citi launches Arc to scale AI agents across the business
    CIO Dive · May 1, 2026
  14. Citigroup says AI helps speed account openings and systems upgrades
    Reuters · Apr 8, 2026
  15. Citi Requirements for Suppliers (September 2026 version), section 19: Artificial Intelligence/Machine Learning
    Citigroup · Sep 1, 2026
  16. Earnings Results Presentation, First Quarter 2026
    Citigroup · Apr 14, 2026
  17. Citi Wealth Unveils "Citi Sky" - An AI-Powered Member of the Citi Wealth Team, Built Using Google Cloud and Google DeepMind Technologies
    Citigroup (PR Newswire) · Apr 22, 2026
  18. US banking giant Citi pilots agentic AI with 5,000 staff
    The Register · Sep 24, 2025
  19. Citi snags AI head from IBM
    CIO Dive · Sep 11, 2025

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