API-first · Headless architecture

Move your business logic from frontend to backend, phase by phase

Reusable APIs your team, partners, and AI agents can consume. Business logic extracted from web and mobile UIs, one capability at a time.

Why this matters

Most API-first migrations stall on the same thing: nobody fully knows where the business logic lives, or what it actually does.

Your business logic has no source of truth

It's scattered across web, mobile, backend, and stored procs. Bug fixes happen multiple times. New features ship asymmetrically. Mobile and web slowly drift apart.

It's slowing the business down

Every change touches multiple places. Engineering velocity drops. Time-to-market grows. And as long as the rules live in the UI, you can't expose them to partners or AI agents.

Big-bang rewrites have failed

You've tried, or considered, a full rewrite. The risk was too high, the timeline impossible. We extract one capability at a time, with the old code paths running until the new one proves parity. No flag day.

How we do it

The hardest codebases resist the usual playbook

Years of business logic embedded in the UI layer. Half in JavaScript, half in backend, no source of truth. Tightly coupled, lightly documented. Static analysis alone misses intent. AI alone hallucinates. Consultants alone don't scale. We run all three.

Layer 01

Deterministic analysis

Our proprietary engine maps where business logic actually lives. Web, iOS, Android, backend, stored procs. Duplication, drift, and dead code surfaced before any extraction starts.

Logic distribution
acme.platform1,254 rules
├─ web/CheckoutFlow.tsx342 rules
├─ ios/CheckoutVC.swift338 rules · duplicated
├─ android/CheckoutActivity.kt340 rules · duplicated
├─ backend/services60% coverage
└─ stored_procs/pricing.sqllegacy · 47 rules
71% duplicated across platforms · 0 source of truth
Layer 02

AI for scale

Anchored in the logic-distribution map, our AI agents apply verified extraction patterns. Rules that drifted across web, mobile, and backend get unified into one source of truth. Each pattern validated once, then scaled.

Drift extraction
Pricing rule across web, iOS, Android → api.pricing.calculate
// Same rule, three platforms, three answers:
- [Web] tier discount BEFORE vat
- [iOS] tier discount AFTER vat
- [Android] tier discount MISSING (bug, 2023)
// One source of truth, server-side:
+ const { tax, total } = await api.pricing.calculate(cart);
Pattern: cross-platform drift → unified API · 187 rules
Layer 03

SMEs and AI experts

Senior engineers validate the extractions, catch the rules that must stay client-side for UX, and surface the cases where the obvious move breaks behavior. The reason your headless migration doesn't ship a worse product.

Extraction review
Senior platform engineer
CheckoutFlow.tsx · input formatting

Currency formatting and input masking must stay client-side. Round-tripping every keystroke through an API breaks input latency on mobile. Locking these 18 rules to the client, with shared validation behind it.

Senior platform engineer
PricingCalculator · real-time inventory

Pricing depends on request-time inventory. Caching the API response breaks parity with the legacy stored proc. Keeping the per-request check, adding an idempotency key for retries.

Engagement model

Phase by phase, no flag day

Four stages. Fixed price per stage. Commit one step at a time, with validation evidence at every one.

01

Assessment

Snapshot of where business logic actually lives. Web, mobile, backend, stored procs. Duplication audit, API surface scoping, candidate extraction order. Scoped plan, risks, success criteria.

What you receive
  • Logic distribution map
  • Scoped plan
  • Risk register
  • Locked success criteria
02

Specification

Define the target API contracts. Extract the business logic, document critical flows, lock parity test specs across web, mobile, and backend.

What you receive
  • API contracts and schemas
  • Extracted business logic
  • Documented critical flows
  • Parity test specifications
03

Modernization

Extract logic into APIs, one capability at a time. Refactor clients to call them. Old code paths keep running until the new one is proved at parity. No flag day.

What you receive
  • Extracted services and APIs
  • Refactored web and mobile clients
  • Deployment scaffolding
  • Parity validation per extraction
04

Enablement

Keep extracting independently. Parity test suite, extraction playbooks, training, and knowledge base, handed off to your team.

What you receive
  • Parity test suite
  • Extraction playbooks
  • Team training
  • Queryable knowledge base
What you get

A workspace, not a stack of files

Every deliverable lives in one place. Yours to keep, queryable by your tools.

Delivered change

  • Extracted services and APIs
  • Refactored web and mobile clients
  • API contracts and schemas
  • One source of truth for business logic

System understanding

  • Logic distribution map
  • Architecture and dependency maps
  • Dead-code and duplication analysis
  • Critical flow documentation
  • Queryable by MCP

Enablement assets

  • Parity test suite
  • Extraction playbooks
  • Team training
  • Queryable knowledge base

An API-first migration that actually ships

Get in touch with our team. We'll talk through your codebase, where the logic actually lives, and the first capability worth extracting.

Get in touch