> Markdown version of [/events/world-congress-2026-europe/sessions/1110-when-should-you-use](https://www.wearedevelopers.com/events/world-congress-2026-europe/sessions/1110-when-should-you-use). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

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# When Should You Use an Agent? Architectural Trade-offs in Agentic Systems


- **Date:** Thursday, Jul 9, 2026
- **Time:** 14:50–15:20 (30 min)
- **Room:** Stage 3 - powered by AWS
- **Event:** World Congress 2026 Europe

## Recording

[Watch recording](https://www.wearedevelopers.com/videos/100109-when-should-you-use-an-agent-architectural-trade-offs-in-agentic-systems)

## Description

Agent-based architectures introduce new execution models that expand what backend systems can do. This session explores the trade-offs between APIs, workflows, and agents through a progressive demo that evolves a real application step by step, highlighting what changes and how to approach these new capabilities in practice.

## Speaker

### [Matheus Guimaraes](https://www.wearedevelopers.com/@matheus-guimaraes)

Developer Advocate at AWS


## Related talks at this congress

- [Headless by Design: Building Enterprise Systems That Agents Can Actually Use](https://www.wearedevelopers.com/events/world-congress-2026-europe/sessions/1099-headless-by-design) — Dirk Gronert
- [Architecture 3.0: From 90% to 99.999% Reliability in Building AI Systems](https://www.wearedevelopers.com/events/world-congress-2026-europe/sessions/1211-architecture-3-0) — Ingo Eichhorst
- [Build Agents Once, Run Them Anywhere: AI Systems That Survive Change](https://www.wearedevelopers.com/events/world-congress-2026-europe/sessions/1471-build-agents-once) — Isha Salania
- [Building APIs for Agents vs Systems. Is MCP the answer?](https://www.wearedevelopers.com/events/world-congress-2026-europe/sessions/1322-building-apis-for) — Adam Bird