Govern & Modernize

API-first modernization for older systems

We put a stable API in front of the system you already run. New products call that API. The old system stays up. A named engineer writes the scope before anyone changes it.

What you get

The order screen, the billing job, and the on-prem system of record can stay. What changes is how new work reaches them. We put a small, stable API in front: which records it may read, which changes it may make, who owns the contract, and how a new caller is turned off without taking the old system down. That is a different job from replacing the system, and a different job from giving a new app a database login. If the job is to move the old system onto a stack your team can keep, start with legacy software modernization. This engagement is the API in front, so new work can ship while that move is still going, or instead of a rewrite. Same idea, other angles. A phone or tablet app that needs the system behind it is Connect a mobile app to your backend or ERP. People who build these connections are Hire API and integration developers. Epic and Cerner connections are SMART on FHIR for Epic and Cerner. We have been shipping software since 2002.

  • A stable API in front of the system you already run
  • A short list of what that API may read and what it may change
  • A named owner for the contract, and a written scope before access
  • New callers can be turned off without taking the old system down
  • The old path keeps working until you choose to retire a piece of it
  • Client code stays in your environment

What we hand back

A written API contract

Named reads and changes

The old system still up

A way to turn a caller off

Why teams call Maxiom

A rewrite is not the first way to let new work talk to an old system.

New work is stuck behind the old database

A portal, a mobile app, or a new checkout needs orders, customers, or inventory. A direct login to the old database couples every new screen to a schema nobody wants to touch.

The rewrite is the plan, and nothing ships

Replacing the system means respecifying behavior it already encodes. Months pass. The warehouse, billing, and the night job still run on the old path, and the new product is still waiting.

Nobody can name what the new caller is allowed to do

If the API can update a price, post a payment, or see every column because that was easier, you did not modernize access. You handed out the keys.

How an engagement works

Kickoff

  1. 01

    Align

    First call · 30 minutes

    We look at the system new work needs to reach, what it may read and change, and whether an API in front is the right first step.

    • The job the new caller has to finish
    • What must stay on the old path
    • Whether a full move should come first

    You get: a clear yes or no on fit

  2. 02

    Scope

    NDA · written plan

    You get a written slice: the contract, the owner, and how a caller is turned off. Not a rewrite of the system.

    • Deliverables, timeline, and a named engineer
    • NDA signed before access
    • Read-only until the scope says otherwise

    You get: a committed written scope

  3. 03

    Execute

    Beside the system you run

    The named engineer builds the API against the system you already operate, with checkpoints you can inspect.

    • Reads before anything writes
    • One caller first, not every future app
    • Client code stays in your environment

    You get: progress you can inspect

  4. 04

    Handoff

    Contract · off switch

    A working API, a walkthrough, and a person who can revoke a caller without stopping the old system.

    • The contract and the permission list
    • The old path still working
    • What to watch the first week a caller is on

    You get: an API you can keep or shut off

Scoping

Talk to an engineer about API-first modernization for older systems

Tell us your stack, timeline, and constraints. We will tell you honestly whether Maxiom is the right fit, and what a scoped engagement would look like.

  • Free 30-minute scoping call: no hard sell
  • Written scope before any repository access
  • Senior engineers only on the work that matters
  • Response within one business day

Prefer calendar? Book a scoping call · hello@maxiomtech.com

Request a scoping conversation

Share a few details and we will follow up within one business day.

Frequently asked questions

The first conversation is scoping. Stack, constraints, and whether we are the right fit.

What is API-first modernization for an older system?

A stable API sits in front of the system you already run. New products call that API. The old system stays the place the work happens until you choose otherwise. You get a written contract: what it may read, what it may change, who owns it, and how a caller is turned off. It is not a rewrite, and it is not a database login for the new app.

Do we have to replace the old system first?

No. Replacement is a different project. The first step is a contract the new work can call while billing, the warehouse, and the night job keep running. If you do want the system moved onto a stack your team can keep, start with legacy software modernization.

What should the API be allowed to do?

A short list. Read the order, the customer, or the inventory fields the new caller needs. Change only what a person has already approved, such as a status the old screen also understands. It should not update a price, post a payment, or see every column because a wide query was easier.

Who owns the API?

A named person who already owns the old system or the integration, plus a backup. That person can say what a caller did yesterday and can turn that caller off. "The team" is not an owner.

How do you turn a new caller off?

Revoke that caller's key, or flip the flag for that caller, without taking the old system down. The old screen, the old job, and the old users keep working. If the only off switch is a deploy rollback, it is not an off switch.

What does the first caller usually look like?

One new path. A customer portal that reads order status. A checkout that posts a status the old order form already understands. A mobile app that must not get a database password. Later callers reuse the same contract. They do not each get their own back door.

Which older systems do you put an API in front of?

Systems the business still runs and nobody wants to rewrite on day one: older .NET, classic ASP, on-premises apps, and the database behind them. A .NET move, when that is the job, is .NET modernization. The API can come first so new work is not waiting on that move.

What if the system holds patient data, or the new work is a mobile app?

Say so on the first call. Patient records and clinical systems go through Maxiom Labs, including SMART on FHIR for Epic and Cerner. A mobile app that needs your backend or ERP is Connect a mobile app to your backend or ERP. People to put on the integration itself are Hire API and integration developers.

How do we start?

A 30-minute scoping call. Bring the system new work needs to reach, and the name of the person who owns it today. We will tell you if the right next step is this API, a modernization of the system itself, or someone else. You can contact us or use the form on this page.

Not sure this is the right engagement? That is what the first conversation is for.

Tell us your stack, regulatory context, and timeline. We will tell you honestly whether Maxiom is the right fit.

  • NDA signed before access
  • Senior engineers every time
  • Written scope before work
  • Client code stays with you