Katz, Sapper & Miller Modernizes Core Infrastructure and Accelerates Growth with AWS

👤 Artie Sluka, Technical Manager and Darren Mills, Chief Technologist | How CleanSlate helped a top 50 CPA firm exit legacy infrastructure, modernize cloud workloads, and unlock 30%+ projected cost savings, without disrupting peak operations. Published 12/22/2025

EXECUTIVE SUMMARY

KSM-modernizes-core-infrastructure-business-results-graphic

Katz, Sapper & Miller (KSM), one of the nation’s 50 largest independent CPA firms, needed to modernize its technology infrastructure to support continued growth, improve resiliency, and control rising costs. Operating across on-premise and Microsoft Azure environments, the firm faced challenges with scalability, uptime, and agility, compounded by a small internal IT team and a fixed 10-week deadline to exit its data center.

KSM partnered with CleanSlate Technology Group to execute a rapid migration and modernization initiative on Amazon Web Services (AWS). In just ten weeks, CleanSlate helped KSM transition critical workloads to a secure, scalable AWS environment, improving performance, reducing operational overhead, and positioning the firm for more than 30% in projected cost savings through optimization and rightsizing.

The engagement demonstrates CleanSlate’s ability to deliver complex modernization initiatives under tight timelines, while protecting business continuity during peak operational periods.

Founded in 1942, Katz, Sapper & Miller is a leading Indianapolis-based advisory, tax, and audit firm serving national and international clients. With more than 700 employees, KSM has grown into one of the largest independent CPA firms in the United States and was recently ranked among the fastest-growing accounting firms nationwide.

As the firm continued to expand through organic growth and acquisitions, leadership recognized that its existing infrastructure was no longer aligned with long-term business goals. KSM needed a modern, resilient foundation that could support future growth, improve disaster recovery, simplify onboarding, and enable emerging capabilities such as AI, without overburdening its internal IT team.

To meet these challenges, the organization strategically partnered with CleanSlate Technology Group, a leading AI consulting and AWS cloud services provider. This collaboration empowered the team to use a combination of AWS resources, including Amazon Bedrock and generative AI to deliver scalable, AI-powered guides and improved subject matter expert experience through secure and scalable innovation. With CleanSlate’s expertise, the organization now benefits from enterprise-grade security (including Amazon Cognito for user identity and access management), concurrency management for scale, and internal tools to build production-grade AI applications that deliver rapid value.

Other industry providers may offer proofs of concept, but CleanSlate built a sustainable and scalable production solution designed to deliver results for years to come.

challenges

Limited Capacity for Modernization

Tight Timeline and Business Risk

KSM was required to exit its on-premises data center within a non-negotiable 10-week window. This transition coincided with the firm’s busiest season, leaving no margin for downtime or operational disruption.

Complex, Interconnected Environments

The firm operated a mix of on-premise and Azure workloads with numerous interdependencies. Migrating these systems required careful sequencing and planning to ensure reliability and continuity across critical business functions.

Infrastructure Not Built for Scale

Legacy configurations include limited performance, scalability, and resiliency. A simple “lift and shift” approach would not have supported KSM’s business objectives around cost efficiency, future growth, and operational agility.

Limited Internal IT Bandwidth

While highly capable, KSM’s internal IT team was lean and needed a solution that reduced long-term operational burden while enabling knowledge transfer and sustainable ownership post-migration.

Solutions

The CleanSlate Solution | Cloud-First Modernization

Cloud-First Modernization Strategy

CleanSlate partnered with KSM to design and implement an AWS-first architecture that prioritized scalability, security, and operational efficiency. Rather than simply migrating workloads, CleanSlate helped re-architect key systems to better align with business goals.

Phased Migration Approach

To reduce risk and ensure continuity, CleanSlate executed the migration in structured waves, allowing workloads to transition incrementally while maintaining performance during peak business operations.

Secure, Scalable Foundation

A governed multi-account AWS environment was established to support long-term growth, centralized oversight, and consistent security controls across the organization.

Enablement for Long-Term Success

CleanSlate worked closely with KSM’s IT team throughout the engagement, providing hands-on enablement and knowledge transfer to ensure the internal team could confidently manage and optimize the environment after the migration.

Results

Improved Performance and Resiliency

CleanSlate successfully delivered a complete modernization and migration within KSM’s aggressive timeline, without disrupting business operations.

Key outcomes included:

Completed full data center exit within 10 weeks
Reduced operational risk by retiring legacy infrastructure
Improved system performance, scalability, and resiliency
Freed internal IT resources to focus on higher-value initiatives
Positioned the firm for 30%+ projected cost savings through optimization and rightsizing

By modernizing its infrastructure on AWS, KSM now operates on a secure, scalable foundation that supports continued growth, future acquisitions, and innovation, while maintaining the reliability and performance its clients expect.

Publish: 12/22/2025

Let’s talk

Thinking about moving to the cloud or assessing your current cloud environment? You probably have questions. We’ll get you the answers you need to help you make the right decision.

Contact us