Haliviq

Modernize Legacy Systems
Without Stopping the Business

Many Thai companies run on software that was written ten or fifteen years ago and still holds the business together. It works, but every change is slow, nobody wants to touch it, and new channels such as a mobile app or a partner integration are hard to add. Haliviq modernizes these systems one piece at a time: we put an API layer in front, move individual functions to newer services, and keep the old system running until each replacement has proven itself. Your staff and customers keep working throughout.

Get Started

We modernize business-critical applications without the long, risky rewrite. The work starts with an assessment of your code, data, and how the system is really used, so we can sort each part into rewrite, wrap, replace, or leave alone. From there we use the strangler-fig approach: new services take over one capability at a time behind an API gateway while the old system keeps serving users. Depending on what we find, that can mean splitting a monolith along its natural seams, adding APIs and event-driven messaging, moving workloads into containers, and migrating data with checks that prove the old and new records match before each cutover. Every step can be rolled back. We also write tests around the existing behaviour first, because a system with no tests turns every change into a gamble. The result is a platform your team can understand, change quickly, and run at lower cost, reached without a six-month period when the business waits for the new version.

Capabilities

Key Capabilities

Concrete capabilities we bring to this engagement — not buzzwords.

Legacy Assessment

We review the code, the data, and how people really use the system, then give each part a verdict: rewrite, wrap, replace, or keep. You receive a written plan with reasons and an order of work that protects revenue.

Incremental Refactoring

Structure is cleaned up and tests are added one section at a time while your team keeps shipping. Each change is small enough to review and to roll back.

Cloud-Native Patterns

Containers, microservices, serverless, and event-driven designs are used where they fix a real problem, such as slow releases or scaling limits. Where a simpler design is enough, we keep it.

API Modernization

A stable API layer in front of the old system lets a mobile app, a partner, or an AI tool use your data without a rewrite. It is often the quickest first step and starts paying back early.

Data Migration

Data moves in stages, with old and new records compared before each cutover and a way back kept open, so mismatches are fixed before users ever see them.

Microservices Decomposition

A monolith is split where the business already draws a line, such as orders, billing or inventory, instead of into arbitrary pieces that then talk to each other constantly.

Patterns We Use

Technologies We Use

Proven architecture patterns we apply where they fit — chosen for the problem, not the trend cycle.

MicroservicesContainersKubernetesAPI GatewayEvent-Driven ArchitectureServerlessCQRS

How We Work

Our Approach

A clear path from legacy to modern — adjusted per system, never one-size-fits-all.

01

Assess

Code, data, and how the system behaves in daily use, including undocumented corners.

02

Strategy

A verdict for each part (rewrite, refactor, wrap, or replace) and an order that protects revenue.

03

Modernize

Small structural changes, with tests around the old behaviour so each one can be checked.

04

Migrate

Platform and data moved in stages, with a rollback ready at every cutover.

05

Verify

Data matches, performance holds, and nothing that used to work has broken.

06

Optimize

Hosting cost, scaling, and daily operation tuned so the new setup is cheaper to run.

FAQ

Straight answers about how we modernize systems.

In small steps, using the strangler pattern. New services take over one capability at a time behind an API gateway while the legacy system keeps running, so nobody waits for a big rewrite to finish. Traffic moves across gradually, only after each new piece has proven itself in production, and every step has a way back if something looks wrong.

Into maintainable, API-first, cloud-ready platforms. Typically that means services in containers on Kubernetes, with event-driven messaging where it helps and serverless where it is simpler. The target design follows your team and your workloads, not fashion. We do not choose microservices by default just because the word sounds modern, and for some systems a well-structured monolith behind a good API is the right answer.

Yes. It is a common starting point, not a blocker. We map what the system really does from its code, its data, and its production traffic, and we talk to the people who use it every day. Before changing anything we write tests that lock in current behaviour, so we find out immediately if a change breaks something.

Rarely. It makes sense only when changing the system in steps would genuinely cost more than rebuilding it, for example when the underlying technology is no longer supported by anyone or the data model is wrong at its core. After the assessment we tell you which side of that line your system sits on. We do not sell a rewrite by default.

A single-module strangler migration usually takes 2-4 months from assessment to full cutover. Decomposing a large monolith is phased over 6-18 months, and each phase delivers working software and measurable progress, so you see results along the way instead of waiting for one long project to end. The size of the system and how well it is understood are the biggest factors.

It depends on the size and complexity of the legacy system and how much of it has to change. A focused assessment typically starts in the high five figures (THB). A phased program is quoted phase by phase after that assessment, so you can see the value of one stage before agreeing to the next. Hosting and licence savings from the new setup are part of the business case we put in front of you.

We work alongside your engineers, not in a separate corner. We pair with them on the parts of the system they know best and hand over knowledge as we go. By handover your team understands the new architecture because they helped build it, not because they were given a document at the end.

You do. New services, infrastructure code, and documentation sit in your own repositories and cloud accounts from the first day. Because we work inside your environment, there is no separate system to move out of at handover.

Have a project in mind?

We'd love to hear what you're building.

Start a Conversationinfo@haliviq.com