Legacy is a good word!

The word “Legacy” often has unhappy connotations of being “outdated” and “high maintenance”. While this may be partially true, the business rules & transactions built into your legacy, over many years, are still highly relevant and valid. Your legacy assets, often become your core business differentiators. A few ways to get more value out of legacy would be to:

  • Wire them together in new ways
  • Make them more accessible to customers and partners
  • Combine them with new capabilities
  • Make them more scalable

A cloud native application model offers you building blocks that help you achieve the above four points and thus transform legacy. The key components of such a model are Containerization, Microservice based Architecture, Automatic Scalability and System Observability.

Typically, legacy applications can be categorized into one of three categories listed below:

In-house developed applications, built on outdated technology that is expensive to maintain, not scalable, with non-availability of skills for feature evolution. These systems severely impact time to market. In most cases, they are not integration-friendly, as they support outdated interfaces.


Third-party, out-of-the-box business applications, that were typically procured several decades ago. The vendor might have stopped developing new features and the systems are nearing sunset stage. Such applications are mostly monolithic in nature. They tend to be black boxes, with data and functions not exposed in a granular fashion.


Business critical applications that are fully functional but built on legacy hardware and operating systems such as Mainframes. The challenge with these applications is to make them integration-friendly and scalable through API-enablement.

Factoring in the above scenarios, we formulated a legacy decomposition process to help put a method to the madness, as illustrated in Fig 1: Legacy decomposition flowchart:

Legacy and cloud-native can and will co-exist

Not all capability from legacy fit into the microservices architectural model. Infact, it isn’t even a best practice to move all capability. When we decompose legacy, we identify application components and data that can be containerized. With a deliberate and careful data migration strategy and decomposition, a monolith can be split into a set of microservices. Parts of the monolith that cannot be decomposed is retained until it is re-engineered or replaced with a third-party product or a SaaS application. If the retained part exposes interfaces, it can be APIenabled as-is, using an integration tool. The three models of co-existence and migration are shown in Fig 2: Models for legacy and cloud native to co-exist

OpEx savings – how and why

The automation, agility and optimization elements in a Cloud Native world offer significant OPEX reduction to CSPs owing to:

  • Processes and workflows – Automation & the ability to reuse assets (common services), is built into every stage of the development and deployment lifecycles. The use of automated tests, Continuous Integration/Continuous Delivery (CI/CD) processes etc. is mandated, reducing time-to-market and costs.
  • Infrastructure - Cloud Native runtime architecture leverages automation to ensure operational stability through end-to-end monitoring, system observability, chaos-engineering. These aspects align towards the SRE (Site Reliability Engineering) discipline that ensures smooth operations for mission critical systems. The ability to harness “as-a-service" models and containerization, at the application level, greatly optimizes hardware investments
  • Business enablement - A fully native, integrated experience to the enduser is made possible through the speed, agility and scalability offered in a cloud-native model of rendition.

….bringing with it, savings due to:

Avoidance of operational challenges with legacy such as frequent hardware upgrades, time consumed in manual deployments, prolonged development and release cycles, frequent production deployment rollbacks, etc. This enables our CSP customers to achieve annual savings of up to 40%.

Hardware & Containerization – Legacy systems traditionally are run on legacy hardware, which require constant upgrades and capacity upliftment due to growing Digital consumption and scaling needs. Cloud Native is built on the foundation of scalable and dynamic capacity provisioning, it introduces a new dimension of automation in the traditional capacity management practice leading to cost and time savings of up to 50% annually.

Tools to standardize and accelerate migration to cloud native

Torry Harris helps IT leaders analyze, extract and modernize functionality from their legacy estate in a consistent manner for a standardized, accelerated move to a cloud native setup. The TMForum compliant “legacy to cloud native kit” enables CSPs to leverage ready-to-deploy digital tools, automation frameworks, and services. The kit accelerates reducing OpEx costs, by building scale and efficiency while standardizing cloud native components across group companies

A micro-gateway:

The DigitMarket™ micro-gateway is deployable as a standalone gateway instance to secure microservices. It has configurable usage policies (throttling, rate limiting, etc.) and security policies ( OAuth, HTTP-Basic, etc. ). A token-based authentication model makes it highly secure.

A deployment automation tool:

Deplomatic is an advanced deployment automation tool. It is a container-based environment provisioning tool, built on Ansible, to provision a sandbox environment, for approval of workflowbased environment creation and continuous deployment. It can be exposed through APIs for easy integration into DevOps based workflows (continuous deployment).

A visual integration tool:

‘Coupler’ is designed to model flows through configuration (drag-anddrop) and expose them on a microgateway. It supports multiple protocols such as SOAP, REST, JDBC, MQTT, JMS, etc. It offers node-based data flow modeling with configurable properties for each node.

A stubbing automation tool:

AutoStub® is an automation tool for API mocking. It has automatic data population capabilities configured for different response parameters. Its intelligent mocking capability helps design stateful data, across API invocations. The tool is used to create DevOps lifecycle automation for microservices by stubbing dependencies for each microservice to enable “testability” of each use case.

An API test automation tool

Automaton™ is a test automation tool to test API flows using a visual approach. It is extensible. It can test beyond APIs. Its API-driven approach helps trigger tests from external scripts. It is used to create DevOps lifecycle automation for microservices through test automation for continuous integration. It can be configured to generate reports for each test execution.

Specific savings enabled by Torry Harris automation tools at each stage of the development, deployment and operations of cloud native applications are captured in Table 1: Annual savings - Legacy to cloud native kit

Key benefits of legacy to cloud native kit:

Migrating select legacy systems to a cloud-native setup is an important step in your journey to build digital ecosystems. And cloud-native will propel your operational efficiency.

The legacy to cloud-native kit offers the following advantages:

A standardized approach, TM Forum compliant

CSPs can achieve their legacy application migration goals faster through automation with a TM Forum compliant toolkit-based approach. You have better predictability and standardization in the journey to establish your cloud-native setup.

Easily managed

Legacy to CN kit is designed with flexibility and simplicity in mind to ensure that the migration of your legacy systems is seamless and hitch-free.

Cost effective and reliable migration

The L2CN kit is cost-effective and guarantees high RoI. With this kit, you can migrate from legacy to cloud-native environments with minimal risks.

High performance and scalable systems

The cloud-native environment achieved through the kit can meet and exceed the high-performance requirements that many enterprises need at the moment. The kit takes into account current and future scaling needs of your enterprise.

Leverages legacy functionality

The kit facilitates retention of what is good about legacy. It helps leverage all your business differentiators built into your legacy systems over the years rather than reinvent the wheel!

Legacy to cloud-native kit

  • Lowers total cost of ownership
  • Reduces complexity
  • Reduces time-to-market
  • Eliminates technical debt
  • Improves agility and scalability
  • Increases responsiveness and flexibility
  • Enables real-time insights
Table 1: Annual savings ­ Legacy to cloud native kit
No Torry Harris tool Area of Automation Annual Savings
1 Deplomatic Deployment automation framework that also provides environment governance and workflow capability. It drives cost efficiency through avoidance of over­provisioning of Cloud resources. Has reduced environment governance cost for customers by 35%
2 Coupler Microservices development framework through visual flow design approach. Ideal for Integration­centric Microservices. Reduces development effort up to 40% compared to a code­based approach for implementation.
3 AutoStub Stubbing Automation tool to automatically generate data­driven API stubs for test automation and facilitate CI/CD Reduces development time by upto 20%
4 Automaton Test Automation tool that provides a visual tool to model your APIs and other application test scenarios Reduces test automation effort by 30%
5 DigitMarket Micro­Gateway Microgateway to securely expose your Microservices through a decentralized policy management Reduces operational cost by 15%

Legacy to cloud-native kit is TM-Forum open digital architecture (ODA) compliant, with tools and frameworks to help you progressively transition your legacy applications to a cloud-native architecture”

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