Applications Build · Modernize · Integrate

The applications your business runs on, built to last .

Billow is an application services company delivering enterprise application services end to end — custom application development, legacy modernization and the integrations that tie your systems together, shipped by one accountable squad.

  • Software application development services
  • Legacy modernization, minimal risk
  • APIs that connect your systems
  • One squad: build, ship, support

What we deliver

Build it, modernize it, connect it

Our application development services cover new builds, legacy modernization and the integrations between systems — the full picture, not just one slice of it.

Application Modernization

Replatform, refactor or rebuild legacy systems into secure, cloud-native applications — cutting risk and cost while keeping the business logic you depend on.

Custom Application Development

Product-grade web and mobile applications for the workflows no off-the-shelf tool fits — discovery, UX, engineering, QA and support from one accountable squad.

API & Integration Services

Connect ERP, CRM, cloud and legacy systems with secure, well-documented APIs — so your applications work together instead of in silos.

Why Billow for applications

One squad from first line of code to long-term support.

A lot of enterprise software development goes wrong at the seams — design thrown over a wall to engineers, then to QA, then to a support desk that never saw it built. We keep it in one accountable team, start to finish.

Product-grade delivery

Discovery, UX, engineering and QA in one squad — software built to the standard of a product, not a ticket.

Modernize without the risk

Legacy systems replatformed or rebuilt in stages, with a clear path — not a big-bang rewrite you cross fingers on.

Built to connect

APIs and integrations designed in, so your applications work with the systems around them instead of becoming new silos.

Support that continues

Our application management services mean the team that ships it keeps it running, secure and improving over time.

How we work

Whatever state your applications are in

New build, ageing system or tangle of disconnected tools — we meet you where you are.

NEW

Starting fresh

Custom development

A workflow no product fits. We design and build a purpose-made web or mobile application around exactly how you work.
OLD

Ageing systems

Modernization

A legacy app that’s costly, brittle or unsupported. We modernize it into something secure, cloud-native and maintainable.
API

Disconnected tools

Integration

Systems that don’t talk to each other. We build the APIs and integrations that make them one connected estate.

How we engage

From assessment to managed cloud

01

Discover

We learn your workflows, users and constraints, and shape the scope — what to build, modernize or connect first.

02

Design

Architecture, UX and a delivery plan — with the integrations and non-functional needs designed in, not bolted on.

03

Build & test

Engineering in iterative sprints with QA throughout, so you see working software early and often.

04

Ship & support

Deploy, then maintain and enhance — application management so it keeps working and improving after launch.

FAQ

Application questions

Enterprise application services cover the full lifecycle of the software your business runs on — building new custom applications, modernizing legacy systems, integrating applications through APIs, and supporting them over time. Billow delivers all of it as one accountable application services company rather than a chain of specialists.
Yes. Our custom application development services design and build web and mobile applications for the workflows no off-the-shelf tool fits — discovery, UX, engineering, QA and support, delivered by one squad rather than handed between vendors.
Yes. We replatform, refactor or rebuild legacy systems into secure, cloud-native applications — reducing risk and cost while preserving the business logic you depend on, with a clear migration path rather than a risky big-bang rewrite.
Yes. Our API and integration services connect ERP, CRM, cloud and legacy systems with secure, well-documented APIs — a core part of enterprise software development that turns disconnected tools into one estate that works together.

Get started

Let's build what you actually need.

Tell us about the application you need built, the legacy system slowing you down, or the systems that won't talk to each other — we'll scope it with you.