# Citizens Financial Group: Technology stack

Source: https://www.bankingnewsai.com/banks/citizens/technology-stack
Last updated: Oct 16, 2026

*Part of the [Citizens Financial Group AI strategy profile](https://www.bankingnewsai.com/banks/citizens).*

## What technology stack does Citizens run its AI on?

Citizens runs on public cloud: CIO Michael Ruttledge says it is 'the first super-regional bank to move its entire mainframe and every business application into the cloud', after migrating 700 applications in four years, and the 2025 Annual Review says it became fully cloud-based in 2025. Business applications sit in AWS and Microsoft Azure, linked through Equinix; the mainframe moved to Kyndryl zCloud and the core is being upgraded with FIS. Data runs through an enterprise data cache on MongoDB Atlas on AWS that, according to AWS, holds core data for 14 million customers and saved $1.5 million a year, with 99.99% uptime. The cloud move closed 25 data centres, cut infrastructure cost 10% to 15% and incidents 78%. Generative AI is part of the migration: it rewrote a mortgage system of millions of lines in six weeks, and Citizens reports code-conversion and testing gains of 10% to 20% (2024) and engineers 30% to 40% more productive (2026). Models come from providers through an internal portal (OpenAI, AWS Bedrock, Anthropic), and an AI-first Innovation Hub with Infosys adds engineering capacity. Technology spending and engineering headcount are not disclosed. ([American Banker](https://www.americanbanker.com/news/citizen-financials-michael-ruttledge-is-43-on-the-most-innovative-people-in-finance-ranking), [Citizens Financial Group](https://investor.citizensbank.com/~/media/Files/C/CitizensBank-IR/pro-014217-2-cfg-ar-2025-web-ready.pdf), [American Banker](https://www.americanbanker.com/news/inside-citizens-plan-to-reimagine-itself-with-ai), [AWS Partner Network](https://aws.amazon.com/partners/success/citizens-bank-mongodb), [American Banker](https://www.americanbanker.com/news/how-citi-citizens-td-deploy-ai-agents-without-upsetting-humans), [Bank Automation News](https://bankautomationnews.com/banking/citizens-sees-up-to-20-efficiency-gains-through-gen-ai), [American Banker](https://www.americanbanker.com/news/tech-leaders-say-ai-could-end-humanity-banks-still-love-it), [Infosys via PR Newswire](https://prnewswire.com/news-releases/revenue-crosses-20-billion-mark-with-resilient-growth-of-3-1-in-fy-26-in-constant-currency-302751870.html))

## What are the layers of Citizens' technology stack?

Each layer as Citizens or its vendors describe it. Vendor-published pages are attributed to the vendor.

| Layer | What Citizens uses | Detail | Source date | Sources |
| --- | --- | --- | --- | --- |
| Public cloud | AWS and Microsoft Azure | Every business application migrated; 700 applications in four years; Oracle Cloud Infrastructure also named in 2025 | 2025-2026 | [American Banker](https://www.americanbanker.com/news/citizen-financials-michael-ruttledge-is-43-on-the-most-innovative-people-in-finance-ranking), [Bank Automation News](https://bankautomationnews.com/allposts/cloud/citizens-on-pace-for-100-cloud-migration-by-q3) |
| Network | Equinix | Networking hub connecting to AWS and Azure | December 2025 | [American Banker](https://www.americanbanker.com/news/inside-citizens-plan-to-reimagine-itself-with-ai) |
| Mainframe and core | Kyndryl zCloud; FIS | Mainframe moved to Kyndryl's cloud; core upgrade with FIS | December 2025 | [American Banker](https://www.americanbanker.com/news/inside-citizens-plan-to-reimagine-itself-with-ai) |
| Data cache | MongoDB Atlas on AWS, with AWS Lambda, Amazon EKS and Amazon Redshift | Per AWS: 14 million customers' core data loaded in under 40 minutes; 99.99% uptime; 30 ms responses for 95% of requests; $1.5 million a year saved | 2026 | [AWS Partner Network](https://aws.amazon.com/partners/success/citizens-bank-mongodb) |
| Mainframe data integration | Precisely | Per AWS, near real-time trusted data across channels and a large cut in MIPS usage | September 2026 | [AWS Partner Network](https://aws.amazon.com/partners/success/citizen-bank-precisely) |
| Fraud platform | MongoDB Atlas on AWS | Cloud fraud-management platform handling about 80% of claims volume since 2023 | February 2025 | [Bank Automation News](https://bankautomationnews.com/allposts/cloud/citizens-on-pace-for-100-cloud-migration-by-q3) |
| Model access | Internal gen-AI portal: OpenAI, AWS Bedrock, Anthropic | No in-house LLM; some models hosted inside the bank's VPC | 2024-2026 | [Bank Automation News](https://bankautomationnews.com/banking/citizens-sees-up-to-20-efficiency-gains-through-gen-ai), [American Banker](https://www.americanbanker.com/news/inside-citizens-plan-to-reimagine-itself-with-ai), [American Banker](https://www.americanbanker.com/leaders/the-ai-enabled-bank-reimagining-retail-banking-from-branch-to-mobile) |
| Developer tools | Microsoft Copilot, GitHub Copilot and its coding agent | About 800 developers; engineers moving to supervise multiple agents | 2025-2026 | [American Banker](https://www.americanbanker.com/news/how-citi-citizens-td-deploy-ai-agents-without-upsetting-humans), [American Banker](https://www.americanbanker.com/news/tech-leaders-say-ai-could-end-humanity-banks-still-love-it) |
| Contact centre | Amazon Connect | Voice agents built into the mobile app, per AWS | September 2026 | [AWS (Amazon Connect)](https://aws.amazon.com/products/connect/customer/resources/customer-contact-week) |
| Engineering capacity | Infosys, AI-first Innovation Hub | Infosys Topaz (2025) and Topaz Fabric (2026) for AI-led platforms and data-centre exit | 2025-2026 | [Infosys via PR Newswire](https://www.prnewswire.com/news-releases/infosys-announces-expansion-of-strategic-collaboration-with-citizens-to-propel-ai-led-transformation-302399928.html), [Infosys via PR Newswire](https://prnewswire.com/news-releases/revenue-crosses-20-billion-mark-with-resilient-growth-of-3-1-in-fy-26-in-constant-currency-302751870.html) |

## What has Citizens reported from its cloud and AI engineering work?

Citizens closed 25 data centres and reports infrastructure costs down 10% to 15%, incidents down 78% and about $45 million of annualised savings from the cloud move. ([American Banker](https://www.americanbanker.com/news/inside-citizens-plan-to-reimagine-itself-with-ai), [American Banker](https://www.americanbanker.com/news/citizen-financials-michael-ruttledge-is-43-on-the-most-innovative-people-in-finance-ranking))

Generative AI converts legacy code: a mortgage system with millions of lines was rewritten and moved in six weeks. Engineering output rose 10% overall and 55% for engineers on advanced agents by June 2026, and AI coding pilots showed gains from 30% to 10x. ([American Banker](https://www.americanbanker.com/news/how-citi-citizens-td-deploy-ai-agents-without-upsetting-humans), [American Banker](https://www.americanbanker.com/news/citizen-financials-michael-ruttledge-is-43-on-the-most-innovative-people-in-finance-ranking), [Yahoo Finance](https://finance.yahoo.com/markets/stocks/articles/citizens-financial-group-inc-q1-164633929.html))

AWS's MongoDB case study quotes Vinod Yadav, unit CIO for core banking, lending and operations technology, saying the always-on data cache lets the bank 'increase developer velocity and the speed at which we bring new features to market'. ([AWS Partner Network](https://aws.amazon.com/partners/success/citizens-bank-mongodb))

## What does the Citizens profile record on this topic?

| Date | Move | Detail | Sources |
| --- | --- | --- | --- |
| Sep 29, 2026 | Coughlin: engineers now 30-40% more productive with AI | American Banker reports the average Citizens engineer is 30% to 40% more productive than a year earlier under the three-year, $300 million Reimagine the Bank project; Coughlin says the role is evolving toward engineers overseeing multiple AI agents, and that AI-existential-risk warnings have 'not really' changed the project's direction. | [American Banker](https://www.americanbanker.com/news/tech-leaders-say-ai-could-end-humanity-banks-still-love-it) |
| Jul 30, 2026 | CDAO Swamy: LLMs as a translator for customer intent; models inside the bank's VPC | On an American Banker panel Krish Swamy said LLMs map what callers say to a small set of intents, that some models run inside Citizens' own VPC, that chatbots answer questions but do not yet execute transactions, and that commercial underwriters share a Copilot prompt library. | [American Banker](https://www.americanbanker.com/leaders/the-ai-enabled-bank-reimagining-retail-banking-from-branch-to-mobile) |
| Jul 16, 2026 | Q2 2026: AI agents in the back office, a 10x engineering pilot | Back-office re-architecture with AI agents orchestrating end-to-end workflows, AI case classification, AI in credit-card contact centres and a first enterprise-wide AI-chat agent; about $7 million of program costs in the quarter. | [Citizens Financial Group (SEC filings)](https://www.sec.gov/Archives/edgar/data/759944/000075994426000133/a2q26earningspresentatio.htm), [MarketBeat (Yahoo Finance)](https://finance.yahoo.com/markets/stocks/articles/citizens-financial-group-q2-earnings-150449628.html), [PYMNTS](https://www.pymnts.com/news/banking/2026/citizens-bank-mobilizes-ai-to-target-450-million-operational-savings-by-2028/), [American Banker](https://www.americanbanker.com/news/citizens-to-exit-in-store-branches-build-standalones-nearby), [Earnings call transcript (The Motley Fool)](https://fool.com/earnings/call-transcripts/2026/07/23/citizens-financial-cfg-q2-2026-earnings-call-transcript) |
| Jun 1, 2026 | The mainframe goes: CIO's cloud-first claim | 700 applications migrated; CiZi −44% call volume; +55% output for engineers on advanced agents. | [American Banker](https://www.americanbanker.com/news/citizen-financials-michael-ruttledge-is-43-on-the-most-innovative-people-in-finance-ranking) |
| Mar 3, 2026 | 2025 Annual Review: first super-regional fully in the cloud; CiZi use up 40% | The shareholder review says Citizens became the first super-regional bank fully in the cloud in 2025, set up a transformation office for Reimagine the Bank, and that CiZi usage rose 40% year over year in 4Q25. | [Citizens Financial Group](https://investor.citizensbank.com/~/media/Files/C/CitizensBank-IR/pro-014217-2-cfg-ar-2025-web-ready.pdf) |
| Nov 20, 2025 | GitHub Copilot's coding agent to ~800 developers | Half the software developers; fintech partners rewriting legacy systems for the cloud. | [American Banker](https://www.americanbanker.com/news/how-citi-citizens-td-deploy-ai-agents-without-upsetting-humans) |
| Aug 6, 2025 | 'First inning' of AI in business banking | AI not yet in the online banking platform; exploring applications, per the head of business banking. | [Banking Dive](https://www.bankingdive.com/news/small-businesses-turn-financial-advice-data-growth-citizens-survey/756992/) |
| Mar 12, 2025 | Infosys collaboration widened to AI-led transformation | Infosys said it would use its Topaz AI offering to help Citizens build cloud-native platforms and exit its data centres; the two had worked together for five years. | [Infosys via PR Newswire](https://www.prnewswire.com/news-releases/infosys-announces-expansion-of-strategic-collaboration-with-citizens-to-propel-ai-led-transformation-302399928.html) |
| Feb 27, 2025 | Fraud platform rebuilt in the cloud with new models | A head of fraud risk said the cloud fraud-management platform on MongoDB Atlas on AWS had handled about 80% of claims volume since 2023, and that new detection models beat the industry detection rate; more than 80% of applications were in the cloud. | [Bank Automation News](https://bankautomationnews.com/allposts/cloud/citizens-on-pace-for-100-cloud-migration-by-q3) |
| Sep 9, 2024 | No in-house LLM: AWS and Microsoft models | Ruttledge said Citizens had no plan to build its own large language models and would use best-in-class models from its providers; gen AI for documentation, code conversion and testing gave a 10% to 20% productivity gain. | [Bank Automation News](https://bankautomationnews.com/banking/citizens-sees-up-to-20-efficiency-gains-through-gen-ai) |
| Jul 26, 2024 | CIO: 90 gen-AI ideas, six pursued, two in production; Copilot pilot lifts productivity 20% | A hackathon produced over 90 ideas. The two live uses were Microsoft Copilot for engineers (pilot showed a 20% productivity boost; rollout to about 1,000 engineers planned) and a gen-AI product assistant for contact-centre staff. A human validates the code and the answers. | [Banking Dive](https://www.bankingdive.com/news/citizens-bank-cio-ruttledge-ai-banking-generative-genai/722507/) |
| Jun 4, 2024 | Van Saun: 'you have to walk before you run' with AI | At a Bernstein conference the CEO said Citizens was putting policies and governance in place first, called customer bots 'pretty advanced', and named code assistance and fraud detection as other targets. | [Banking Dive](https://www.bankingdive.com/news/citizens-ceo-bruce-van-saun-ai-banking-cloud-digital-trends/717947/) |

## Common questions

### Is Citizens fully in the cloud?

Yes, by its own account. CIO Michael Ruttledge said in 2026 that Citizens is the first super-regional bank to move its entire mainframe and every business application into the cloud, after migrating 700 applications in four years, and the 2025 Annual Review says Citizens became the first super-regional fully in the cloud in 2025.

### Which cloud providers does Citizens use?

Amazon Web Services and Microsoft Azure are its two main public clouds, connected through Equinix; Oracle Cloud Infrastructure was also named in 2025. The mainframe moved to Kyndryl's zCloud, and the core banking system is being upgraded with FIS.

### How does Citizens use AI in software engineering?

About 800 developers, half its software engineers, use GitHub Copilot, some with its coding agent, and generative AI converts legacy code for the cloud, including a mortgage system rewritten in six weeks. President Brendan Coughlin said in September 2026 that the average engineer is 30% to 40% more productive than a year earlier.

### What data platform does Citizens use?

AWS describes an enterprise data cache on MongoDB Atlas that holds core data for Citizens' 14 million customers, built with AWS Lambda, Amazon EKS and Amazon Redshift, and credits it with $1.5 million a year of savings. The same database runs under the bank's cloud fraud-management platform.
## Deeper on Citizens

- [What is Citizens Financial Group's AI strategy?](https://www.bankingnewsai.com/banks/citizens/ai-strategy)
- [What AI partnerships and patents does Citizens Financial Group have?](https://www.bankingnewsai.com/banks/citizens/ai-research-patents-partnerships)
- [What is CiZi, and how is Citizens using AI assistants?](https://www.bankingnewsai.com/banks/citizens/virtual-assistant)


---

Canonical page: https://www.bankingnewsai.com/banks/citizens/technology-stack
Part of [BankingNewsAI](https://www.bankingnewsai.com/) — a free daily brief on AI in banking, an AI regulation tracker (42 authorities, 243 documents) and AI-strategy profiles of the 120 largest US banks. Markdown versions of every reference page: append `.md` to the page URL; index at https://www.bankingnewsai.com/llms.txt.