I build the whole feature — from interface to API, data, and production AI.

7+ years across startups, consulting, and enterprise, spanning web and mobile development. This site is the public interface of my engineering knowledge base: real problems, the decisions and trade-offs behind them, and what they taught me.

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Cúcuta, Colombia 7+ years building

Human layer Cúcuta, Colombia · remote

7+ years of professional experience

4 roles with confirmed end-to-end vertical delivery

React Native · AI cross-platform & LLM in production

01 pattern: vertical delivery

Selected work

The interesting part is the reasoning.

Case studies that make the invisible work visible: constraints, architecture, trade-offs, and the lessons that survive the project.

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Case study 2025 — 26

Privacy-first architecture on a healthcare platform

On a platform handling sensitive healthcare data, protecting it wasn't a feature — it was the architecture.

Node.jsNestJSX25519 KeypairsArgon2id KEK

Case study 2025 — 26

Bringing LLM features into production

Calling an AI API is easy. Making it a reliable feature of a product at scale is the actual engineering.

React NativeZustandNativewindClaude API

Personal projects

A small lab for live ideas.

A focused shelf for software I am building outside client work — selective, public, and honest about what is still in progress.

See the showcase

HeartKushTool Index

AI agent tools marketplace

Personal project

In progress

HeartKush Tool Index

A public catalog for inspectable AI-agent tools — skills, MCPs, hooks, harnesses, and integrations with visible boundaries and activation paths.

marketplace.ismaparra.com

How I work

Vertical delivery. Clear ownership. Fewer workarounds.

I follow a feature across the layers it touches — interface, API, business logic, and persistence — and fix problems where they actually live.

Read the full approach

Signature pattern

End-to-end vertical feature delivery

Consistently shipping complete features across every layer — mobile (React Native), web frontend, GraphQL/API, and backend data — rather than owning a single horizontal slice. A pattern confirmed across four roles: SmartBeemo, House Edge, Sophos, and Infodec.

frontend → API → data

From the field notes

Decisions with receipts

Technical choices are only useful when their costs are visible too.

Read the articles

Decision Application-level PII encryption over database-only encryption

Article Privacy by design, not by retrofit Article Stop fixing backend problems in the frontend

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Have a hard product problem?

Tell me what is getting in the way. I like the part where the system becomes clear enough to change.

Email Ismael