Substack
substack.com
Longer-form writing and current thinking.
Current writingLong-form notesDirect canonical route
Writing
Essays distributed on Substack, with deeper architecture companions here.
Substack is the reading and subscription channel. This site adds the parts an email platform cannot carry well: interactive flows, zoomable system maps, wide decision tables, and downloadable implementation artifacts.
Channels
Start with the current channel, then use the archive when you want older material.
This route stays curated and external-first rather than behaving like an automated import of every profile post.
Medium
pcoletsos.medium.com
Published articles and older writing.
Older essaysHistorical archiveSelected back-catalog
High-fidelity companions
Architecture material that needs more room than an email canvas.
Use the simulations for behavior, the blueprint for topology, the table for trade-offs, and the config as a starting point—not a production policy file.
simulation
Token exchange flow lab
Run valid, expired-token, and rate-limited identity scenarios with an execution trace.
Open simulationsimulation
GenAI guardrail routing lab
Inspect allowed, denied, and budget-limited AI requests across the control plane.
Open simulationblueprint
Enterprise GenAI 4K blueprint
A full-width reference map for identity, policy, retrieval, model access, tools, and evidence.
Open 4K SVG
download
Guardrail routing configuration
A public-safe YAML starter for policy routes, risk tiers, budgets, and evidence collection.
Download YAML| Route | Data boundary | Tools | Human control | Evidence |
|---|---|---|---|---|
| Knowledge answer | Approved index | None | Review on low confidence | Sources + checks |
| Draft workflow | User-authorized records | Preview-only | Confirmation required | Inputs + proposed mutation |
| Bounded action | Purpose-scoped data | Typed allowlist | Step-up approval | Policy + tool result + actor |
Curated entries
Latest essays sync from Substack and keep the canonical source intact.
The feed refreshes hourly when available; approved YAML entries remain as a resilient build-time fallback.
SubstackJune 2026
n8n vs LangChain is the Wrong Question
Choose the orchestration layer by finding where complexity, state, and failures actually live
Canonical route
substack.com
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From writing to engineering proof
Review the technical architecture cases, see the career timeline, or get in touch.