AI Stack 2026: What You Actually Need
Vendors will sell you everything. Here's what it actually takes to run working AI in your company.
"You need an MLOps platform, a data lake, a feature store, a model registry, a vector database, LLMOps..." That's how a typical conversation with a vendor goes. In reality, most companies need far less.
Minimum Viable AI Stack
Before you buy yet another tool, check whether you have the fundamentals:
LAYER 1: DATA
- Data Warehouse: Snowflake, BigQuery, or PostgreSQL for small companies.
- ETL: Airbyte, Fivetran, or dbt for transformations.
- Vector DB (if RAG): Pinecone, Weaviate, pgvector.
LAYER 2: MODELS
- LLM API: OpenAI, Anthropic, Google.
- Orchestration: LangChain, LlamaIndex, or your own code.
- Prompts: Version them in Git, not in a spreadsheet.
LAYER 3: APPLICATION
- Backend: FastAPI, Node.js, whatever you know.
- Frontend: React, Vue, or integration with your existing app.
- Auth & Security: Don't reinvent the wheel.
What you DON'T need at the start
Seriously, don't buy these before your first working pilot:
- ✗ MLOps platform: Git plus simple CI/CD is enough.
- ✗ Feature store: needed at scale, not at the start.
- ✗ Model registry: at the beginning you have 1-2 models.
- ✗ Enterprise AI platform: 6-figure cost, 12-month rollout.
"The best stack is the one you know. Don't learn Kubernetes just to ship a chatbot."
This is what I do hands-on — advising on AI strategy and building agents that survive the demo.
Build vs Buy: A decision framework
Every component of the stack is a build vs buy decision:
BUY (almost always)
- • LLM: don't train your own language model.
- • Infrastructure: cloud, not your own servers.
- • Auth: Auth0, Clerk, not a homegrown solution.
BUILD (usually)
- • Domain logic: nobody knows your business better.
- • Legacy integrations: vendors don't support your 2005 ERP.
- • Prompts and workflow: this is your IP.
DEPENDS
- • Orchestration: LangChain vs your own code (depends on how complex your flow is).
- • Vector DB: managed vs self-hosted (depends on scale).
- • Monitoring: custom vs off-the-shelf tool (depends on team maturity).
Stack evolution
An AI stack grows along with your needs. Here's the typical path:
- Phase 1 (Pilot): OpenAI API + a Python script + a spreadsheet to track results.
- Phase 2 (MVP): you add a database, a simple frontend and basic monitoring.
- Phase 3 (Production): CI/CD, proper logging, alerting, backups.
- Phase 4 (Scale): now consider an MLOps platform, a feature store and the rest.
Real costs
For a mid-sized company (100-500 employees), a realistic AI stack can cost:
MONTHLY INFRASTRUCTURE COSTS
- LLM API: 500-5,000 PLN (depends on volume).
- Cloud (compute, storage): 1,000-3,000 PLN.
- SaaS tools: 500-2,000 PLN.
- Total: 2,000-10,000 PLN/month.
This is not a 6-figure budget. But it does require a 6-figure budget for the people who build and maintain it.
Where to start
The most expensive tool is the one you don't use. Start with the OpenAI API and a single Python script. Add the next tool only once a concrete problem actually starts to hurt.
I've deployed AI at mid-sized companies. That's where this comes from.