United StatesProfessional services2026 – ongoingPwC
Claude Code for legacy and mainframe modernization discovery and proposal drafting
PwC cut legacy code analysis from about six weeks to about two and a half days with Claude Code
Problem
PwC's legacy and mainframe modernization practice spent weeks on discovery work for each client engagement. That work covered document review, stakeholder interviews and interim deliverables. Drafting proposal responses and specifications was also manual.
Approach
The practice, led by Partner Ussama Baggili, used Claude Code to analyze legacy systems and produce findings, recommendations and client-ready decks. PwC packaged its proposal and offering workflows as Claude skills and plugins. It also ran a training session in which a coach plugin walked 400 leaders and consultants through their first prompts, and a firm-wide training rollout for 30,000 people was underway.
Results
Takeaway
The partner leading the practice reported that discovery work that took weeks now takes days, and the firm's proposal drafts reached a first version in minutes. The page does not say how the timings were measured.
Categories
- Size
- Large enterprise
- Industry
- Professional services
- Business function
- Internal work and knowledge management
- Innovation type
- Process innovation
- AI technology
- Generative AI
- Adoption
- Off-the-shelf tool or platform
- Evidence
- Company's own claim
Sources
Source summaries
Anthropic's customer story describes how PwC's legacy modernization practice used Claude Code for discovery work and proposal drafting, and how a training session brought 400 people into it. It quotes the practice lead on six weeks of work shrinking to about two and a half days and gives 15 to 20 minutes for an initial draft RFP response. The page carries no date; the Internet Archive first saved it on June 6, 2026.
Full details are in the original sources.