Stacking
Stacking

Intelligent systems
for specialized domains.

We build tools that help professionals work with complex knowledge, context, documents, and domain-specific decisions — making expert work more contextual, consistent, and efficient.

We bring advanced intelligence into expert workflows.

Stacking is a technology startup from Lublin, Poland. We focus on specialized domains where professionals work with complex knowledge, documents, and decisions that resist one-size-fits-all automation.

Our approach is layered: understand the domain context, surface the right sources, and prepare recommendations that experts can verify — not black-box answers that bypass human judgment.

Lublin, PL
Based in
Domain intelligence
Focus
Early startup
Stage

Systems we've built — and what we're building next.

Each project starts in a specialized domain where professionals need more than automation — they need intelligence that respects context.

01

StackInvoices

In pilot

AI assistant for accounting decisions

Helps accountants resolve non-obvious invoice costs. Pulls client context, regulations, and policy into one recommendation with a full audit trail — the human stays in control.

Accounting · Documents · Decisions

02

ksef2

Open source

Python SDK for Poland's KSeF v2 API

Open-source client and tooling for the National e-Invoice System — authentication, sessions, invoice send and export, FA(3) builder, batch flows, and full API coverage. Maintained in public on GitHub.

Open source · Python · Compliance

03

Your domain

Open

We build where expertise meets complexity

Legal, healthcare, compliance, operations — anywhere professionals need context-aware tools instead of generic automation. Tell us about your workflow.

Partnership · Custom systems

Let's talk about your workflow.

Whether you want to join a pilot, explore a partnership, or just understand what we build — leave your details and we'll get back to you.

hello@stacking.pl

We usually reply within 2 business days.