Back to Blog

Lean Enterprise Architecture: The Company API

How to build business resilience with modern architecture?

Working with business-critical data and APIs across our client projects – we noticed a recurring issue. While everyone is already “in the cloud” or at least have started the transition, there are business-critical solutions that will remain in use for years. And they won’t necessarily be easily replaced - even lifting them to the cloud won’t solve the problems.

A clean API architecture can give your existing systems some more years to live and let you plan the system endpoint lifecycle with some more peace of mind. We have come to believe that splitting your API’s architecture into three distinct layers will simplify your Enterprise Software Architecture and allow your teams to create tangible results within a quarter instead of years.

Simply put, the model saves money and reduces time to market

The layers we propose are:


The three layers each serve different needs and have distinct data integrity, availability, and security requirements. And they are often not only developed by separate teams but with completely bespoke technologies.

The customer-facing APIs focus on usability and access over integrity. The data is cached, and changes happen Near-Real-Time. User access is often anonymous or requires additional IAM.

Partner APIs connect and allow connections to systems outside the company. The requirements, functionality, and the cadence of updates varies widely from a solution to another - and the integrity of the data is often much more desirable than speed or access.

The Company API is a one-stop-shop for your business-critical data. It acts as a single source of truth, emphasizing real-time updates, and high internal integrity.

Why create a separate Company API?

Companies produce and consume vast amounts of data, and today's workforce needs advanced tools to be efficient. Moving to AI and automation based tools will require a single source of truth to work.

While lift and shift strategies have let us benefit from the cloud, their implementation has often focused only on one of the three domains. To build a resilient business, a company needs a holistic vision over all the domains.

In harsh reality, many of the business-critical systems predate the world of cloud and API ecosystems. With the three-layered approach, you can black box the legacy systems without the need for multiple touchpoints and massive master data management programs. Trying to combine the requirements of the Company API with Customer or Partner API's needs will compromise the needs of the Partner and Customer services. And can lead to complicated security mechanisms.

What do we offer:

  1. Love the problem: We can help you understand the three domains and map your current or vision state to the model.
  2. Analyze: We can help you identify your existing systems and facilitate the discussion between developers of different systems.
  3. Build: The time to start implementing a company API is now. We have experience building the thinnest viable solution to prove the value of the Company API concept while providing your company with a resilient pathway to the future.


  • Portrait of Antti Lammi
    Antti Lammi
    Head of Technology
  • Portrait of Ville Takanen
    Ville Takanen
    Tech Principal