Modernisation of
legacy systems

We build and modernise large-scale systems, such as ERP and PIM solutions – tailored for efficiency with no disruptions to daily business operations.

Business-critical systems are the cornerstone of a digital strategy: they have a direct impact on the efficiency of daily operations, competitiveness, and information security.

When does a system require modernisation?

Taiste staff member together with Hesburger staff

Measurable benefits

Approaches to system modernisation

Modernising a system does not always mean a complete overhaul. There are several ways to develop or replace the current solution – from light interface solutions to a full rebuild. Below are six of the most common approaches, which we can combine case by case according to your organisation’s needs, budget, and technical situation.

Improve the existing system

Encapsulate

Modern API interfaces are added to the existing system, enabling the deployment of new functions and integrations without major changes to the system’s internal structure.

This approach is particularly suitable for stable, business-critical systems whose lifecycle is intended to be extended and whose capabilities are to be expanded in a controlled manner.

Refactor

Improving the internal structure of the code and reducing technical debt without altering the system’s functionality.

The goal is to clarify the architecture, eliminate unnecessary dependencies, and enhance performance. The result is a system that is easier to maintain, scale, and migrate to modern environments.

Migrate to a new environment

Replatform

The system is migrated to a modern runtime environment with minimal code changes, without significant structural or functional redesigns.

The goal is to improve performance, scalability, and maintainability, while ensuring the system’s continuity in a modern infrastructure. This is a cost-effective and low-risk way to extend the system’s lifecycle and lay the foundation for future development steps.

Rearchitect

The system’s foundation is overhauled to support future requirements, such as increasing user numbers or evolving business models. This overhaul may involve, for example, migrating to a distributed cloud environment or adopting event-driven solutions.

The goal is to create a scalable and flexible system that enables rapid development and facilitates the deployment of new functionalities.

Rebuild completely

Replace

The old system is decommissioned and replaced with a new, customised solution that meets current and future needs without the constraints of legacy technology.

This approach is often the best option when the system is technically outdated, its architecture no longer supports development, or maintenance has become uneconomical.

Rebuild

The system is completely redesigned and implemented using modern technologies while preserving the original business requirements and core logic.

The result is a clear, scalable, and technically up-to-date solution that improves performance and security and supports future development.

System modernisation project in practice

Assessment and user-centred design

We map out the current state of the system: how well does it serve the size, goals, and users of the business? How up to date is it technically? With a clear overall picture, we identify the risks, opportunities, and implementation options.

Taiste developers thinking about a problem

Technical
implementation

We design and implement the system’s technical overhaul – whether that means rearchitecting, updating technology choices, changing component structures, fixing the codebase, or handling data migrations and structural changes.

Connectivity and Data Structures

We ensure that the new system works seamlessly as part of your organisation’s wider system landscape and ecosystem. Modern, well-documented API interfaces, scalable integration solutions, and tailored data structures lay the foundation for long-term success.

10 risks of system modernisation – and how to overcome them

Get the guide

Custom product or commercial software?

Choosing between a custom solution and off-the-shelf software is one of the key decisions in a system modernisation project. At Taiste, we specialise in solutions tailored to your company’s needs. We either build a product from scratch or adapt an open-source solution to suit your business – but we do not implement commercial off-the-shelf software such as Salesforce or SAP.

Custom system

A software solution designed specifically for the business, giving full ownership of the code and intellectual property, as well as the flexibility to adapt and switch vendors without losing the system.

Client owns software, code & IPR

Development, hosting, support

Product adapts to business needs

Vendor can be changed without losing the software

Commercial software

A ready-made product owned by the vendor, offering quick deployment with standardized modules, but requiring ongoing license fees and creating dependency on the provider.

Vendor owns software, code & IPR

Licenses, development, hosting, support

Business adapts to product

Switching vendors typically requires switching the software

Why choose Taiste as your
system modernisation partner?

A clear roadmap from strategic goals to execution

A practical plan aligned with your core business objectives
User-centered UX design, prototyping, and testing
Modern architecture and framework choices that scale with your needs

All the necessary expertise in one team

Our team includes all the key roles: developers, UX/UI designers, DevOps specialists, project management, and quality assurance.
Flexible resourcing gives you peace of mind – the right experts for every stage are always at your disposal.

Smart cost-efficiency without compromising quality

A simple billing model based on actual work done
An optimised team setup that maintains high quality
We make use of ready-made solutions and integration libraries that speed up delivery
No vendor lock-in: open-source code and technologies supported well into the future

Development principles

Case examples

Hesburger

Hesburger ERP system

Hesburger’s ERP system is the tailored backbone of nearly 500 restaurants, seamlessly supporting daily operations and adapting to a growing business environment.

Taksikuutio

SoteKaista taxi service

SoteKaista helps Finnish disability service clients to decide how they want to travel by taxi.

Aalto university

Design System

A design system for one of the largest universities in Finland. Built to encourage creativity.

Modernisation of
legacy systems

When does a system require modernisation?

Measurable benefits