# Build the Logic. Buy the Platform.

> AI makes business logic cheap to build, not the platform it runs on. Why SaaS is unbundling, what to build, what to buy, and what owning a platform really costs.

Source: https://www.kognitos.com/build-vs-buy/

Based on: [Build the Logic. Buy the Platform.](https://www.kognitos.com/whitepaper/build-the-logic-buy-the-platform/), a Kognitos position paper by Binny Gill.

SaaS sold you a platform you couldn’t build, wrapped around business logic you couldn’t control. AI unbundles the two. Own the logic. Buy the guarantees.

## SaaS configured your logic. AI lets you own it.

One product had to fit thousands of companies, so your process became settings, and whole ecosystems of administrators and consultants grew up to finish the logic the menus left out. Now a builder can describe what a process should do and have working logic in hours, not a quarter. Logic is where a company’s differentiation lives, so it should be yours.

What SaaS gave you: a rule configured through menus (trigger: invoice received; condition: amount over the PO amount; action: route to approver). What you need, accepting freight under 2% from a trusted vendor and otherwise asking the buyer why, has no menu.

With AI, the same rule in English as Code (Invoice exceptions):

*Receive and match*

1. Read the invoice and find its purchase order.
2. Compare the invoice total with the purchase order total.

*Handle the difference*

3. If the difference is a freight charge under 2% and the vendor is on the trusted list, accept the invoice.
4. Otherwise, ask the buyer why, and wait for the answer.
5. Record the decision and the reason with the invoice.

> **Don’t re-bundle.** Point solutions and AI-flavored SaaS put your logic back in someone else’s model and menus, now with a chat window on top. That isn’t owning it.

## AI made code cheap. It didn’t make owning a platform cheap.

Coding agents can write much of a platform’s code. They don’t carry the pager, sit through the audit, or keep connectors alive as other vendors change their APIs. Here is what each guarantee asks of you every year, from running the Kognitos platform.

| Guarantee | What you own, every year |
| --- | --- |
| Deployment and environments | Upgrades, cluster maintenance, release engineering |
| Scaling and performance | Capacity planning, performance regressions |
| Reliability and SLAs | 24/7 on-call, incident reviews, SLA reporting |
| Orchestration and state | Stuck-run triage, migrations of in-flight state |
| Security | Patching, penetration tests, vulnerability response |
| Governance and permissions | Access reviews, policy changes |
| Audit and replay | Evidence requests, retention, auditor walkthroughs |
| Compliance | Annual audits, control testing, remediation |
| Logging, metrics, and monitoring | Alert tuning, observability costs |
| Connectors | API changes on every connected system |
| Document understanding | Model updates, new document types |
| Exception handling with people | Workbench operations, reviewer tooling |
| Model management and evaluations | Model upgrades, evaluation suites, inference cost control |
| Authoring, versioning, and the logic runtime | Language and runtime evolution |

## Three ways to get business logic into production

Every company that wants AI to run real processes picks one of these, whether it decides explicitly or not. Only one keeps your builders on the logic without handing your CIO and CFO a platform team.

### Buy SaaS or point solutions

The vendor’s logic, configured through menus, on the vendor’s platform. You own the logic: 0/3; The business can read it: 1/3; Platform guarantees included: 3/3; Small team to run it: 2/3; Fast to first value: 3/3; Light in year two: 2/3. Fast and reliable. Your process bends to the product.

### Build everything

Your logic, on a platform your team builds and runs. You own the logic: 3/3; The business can read it: 1/3; Platform guarantees included: 0/3; Small team to run it: 0/3; Fast to first value: 2/3; Light in year two: 0/3. Full control, and a platform company you didn’t mean to start.

### Build the logic on a platform

Your logic, written in a form the business can read, on guarantees you buy. You own the logic: 3/3; The business can read it: 3/3; Platform guarantees included: 3/3; Small team to run it: 3/3; Fast to first value: 3/3; Light in year two: 3/3. Builders build what matters. One failure mode to test for: a platform that quietly constrains the logic.

### Should you build the platform too?

- Is the platform itself your product?
- Do you already run a platform team with 24/7 on-call?
- Can you pass SOC 2 and customer security reviews on it this year?
- Will you fund the team that runs it for as long as the logic runs?

Building the platform only makes sense if every answer is yes.

## Already on Copilot Studio or Power Automate?

Run them through the same test: does the platform leave your logic unspecified, and carry the guarantees underneath?

### Power Automate

Good at: routine glue across Microsoft 365, approvals, notifications. Against the test: the logic lives in the designer’s boxes and expressions, configuration again, strained by exception-heavy, auditable work.

### Copilot Studio

Good at: conversation, Microsoft 365 grounding, fast agents. Against the test: a model plans the control flow at run time. Its own architecture guidance recommends enforcing business invariants in deterministic logic as well.

### Kognitos

Good at: rules that must run the same way every time, exceptions resolved by people, audit and replay. Works with them: Kognitos automations can be called from Copilot Studio.

Flow: Ask in Copilot → Copilot Studio agent → Kognitos automation · English as Code → Answer, with a record

## Questions about building and buying

### Is SaaS dead?

Not as software people buy. What is dying is the bundle: the assumption that to get a reliable platform you must also accept a vendor's version of your business logic. AI makes the logic cheap to build, so companies will own more of it and buy the platform underneath.

### Should we build or buy AI agents?

Build the business logic, because it encodes how your company works and should be yours. Buy the platform it runs on: deployment, scaling, security, governance, audit, monitoring, and SLAs. Avoid point solutions that encode your logic in their own menus.

### Can coding agents build our platform?

They can write much of the code, quickly. They can't carry the on-call rotation, sit through the SOC 2 audit, patch vulnerabilities, keep connectors working as APIs change, or explain old decisions to an auditor. Those recurring costs are people costs, not token costs.

### What should we never build ourselves?

Anything that isn't your business and has to be correct every day: the runtime, scaling, security, compliance evidence, audit and replay, and connectors to systems that change underneath you.

### We already have Copilot Studio and Power Automate. Do we need another platform?

They are good at conversation, Microsoft 365 grounding, and routine flows. Business logic that must run the same way every time, with exceptions handled by people and a replayable record, needs a platform built for it. They work together: Kognitos automations can be called from Copilot Studio.

### What is a platform that leaves the business logic unspecified?

One that specifies everything SaaS used to carry and constrains nothing about your logic. Any rule can be expressed fully, the business can read it, it runs deterministically where it matters, and exceptions are resolved by people. Kognitos does this with English as Code.

### When does building the platform yourself make sense?

When the platform is your product, when you already run a platform team at scale, or when a constraint no vendor can meet forces your hand. Otherwise it means entering a business you didn't plan to be in, for as long as the logic on top of it runs.

### How much does it cost to build an AI automation platform?

With coding agents, writing the code is the smaller part. The larger, recurring cost is supporting every platform guarantee in-house: on-call, security and compliance, connectors, and model operations, for as long as the logic runs.