Legacy System Modernization

Evolve today’s software into next-generation experiences.

Transform your current business systems and infrastructure to deliver better value and better results. With a focus on analysis, engineering, and training, legacy system modernization offers next-generation experiences for time-tested organizations.

Our modernization services optimize existing applications, infrastructure, and skills with streamlined development, testing and deployment of enterprise applications for multiple platforms.

Trusted on Mission-Critical Systems

Modernization is about more than new interfaces and technology. It’s about seeing intentions and goals in a bold new light that can help you better serve customers and employees, without throwing the baby out with the bath water.

Theorem helps you define your next-generation technology goals and develop a comprehensive roadmap to reach them. We’ve partnered with dozens of major organizations to help them reimagine, reddesign, and rearchitect legacy systems and platforms for today’s (and tomorrow’s) challenges.

Roadmaps to the Future

We’ll work with you to craft realistic timelines and budgets, design elegant solutions, and define a path towards incremental improvement that rests on the foundation of the technological reality in which you are operating today.

Integrated Technology Teams

Theorem’s polyglot, technology and strategy teams will integrate themselves seamlessly into your existing organizations to collaboratively transform legacy systems, infrastructure, and applications into modern, end-user-centric experiences.

Training for Tomorrow

As a core part of modernization, we also focus on enabling your next-generation of talent. We analyze existing workforces for strengths and weaknesses, and design for critical process improvements that can ensure long-term successful operation and continued evolution of the post-modernization systems, platforms, applications, and services.

What does Legacy System Modernization look like?


Start from First Principles

Success starts with asking the right questions and defining the right approach. We work with you to define what success looks like—then build the right approach for achieving it.


Build on top of Existing Investments

As part of the solution design, Theorem compares your existing investments with desired outcomes to determine the right mix that maximizes gains and minimizes risks.  


Pilot, Test, & Adjust

After we prioritize a modernization roadmap, we’ll leverage an iterative approach to product design and piloting that enables us to deliver real-world results sooner.


Design the Best Possible Experience

The right experience drives the right business results. We test your new platforms and processes to uncover a modern, seamless, and effective end-user experience.


Evolve and Stay Modern

Theorem will help you keep systems and processes in-line, and will also help you develop business capabilities to foster ongoing research and evolution.

A Modernization Roadmap


Modernization Planning

We will work with you to develop a roadmap for the modernization of your enterprise — from architecture and teams to applications and infrastructure — and help inform you of realistic timelines and budgets.

System Architecture

We will analyze your existing code-base, business objectives, and team capabilities then recommend architecture, process, and system improvements based on those findings.

Application, Platform, and System Design

We design elegant user interfaces for your modernized applications, systems, and platforms. Each experience is  uniquely designed to drive the rights value-based outcomes.

Workflow Automation

We will analyze your business processes and enterprise workflows to look for places to introduce automation, remove manual processes, reduce headcount, reduce QA time, reduce failure rates, increase revenue, and more.


Legacy Data

We migrate and integrate legacy data into modern systems with better error handling, failover and redundancy. During this process we restructure and merge data from different sources so that applications and systems can access data in new ways.

Building New Software & Porting Legacy Systems

Using our proprietary modernization process and tooling, we deliver on the modernized application and architecture that we’ve planned, building new software, and converting, rewriting or porting legacy systems as needed.

Working with your Teams

We know how to integrate ourselves into your existing teams and create project plans that delineate work effectively across many teams with different strengths.

Delivering Quality Software

We implement QA and code-review processes that ensure both our teams and your existing teams deliver the high-quality software that your business needs.


Code Reviews

By performing code reviews we can identify strengths and weaknesses in your team to help you restructure your existing talent pool, and create process improvements that will lead to quality and efficiency improvements.

Process Redesign

We help you improve your team’s internal capabilities through redesign of core internal functions:

  • Project management

  • Tactical & Strategic Planning

  • Product Development Estimation

  • Requirements & Feature Definition

  • Quality Assurance (QA) Processes

  • Product Realization

  • Team Structure

  • Team Performance Management

  • Product Ownership

  • Defect Triage and Management

  • Multi-Tier Support

  • DevOps

  • Remote & Distributed Collaboration

  • Engineering Collaboration

  • Product / Design / Engineering Interface

  • Security & Threat Monitoring

  • Data Collection, Aggregation and Analysis

  • Customer-Driven Research

  • User Experience Practices

Team Training

We can bring experience in newer methodologies, libraries and tools to your team and help them answer questions they have about new technologies, methodologies, and approaches. We frequently train our customer’s teams in:

  • Frontend technologies like Node.js, React, and Angular

  • Design and architecture for high-availability systems

  • Web-stack programming like Ruby, Python, Go, Erlang

  • Databased technologies like Redis, Mongo, Couchbase

  • DevOps, Cloud infrastrucute, CICD

Ready to Modernize?

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