Santiago Hernández

I lead products from problem framing and design validation through production.

As a Tech Lead, I work across web, mobile, and AWS, use AI coding agents to deliver, and help teams adopt AI through clear rules.

What I bring to a team

Projects change. These are the skills I bring to each one.

Career path

  1. 2019-2021

    Project Manager

    Managed projects and coordinated delivery at an educational nonprofit organization.

  2. 2021-2026

    Full-stack Engineer

    Worked across web, mobile, backend, and AWS, and contributed to the organizational standard for working with AI.

  3. 2026-today

    Tech Lead

    Lead engineering for products in production: architecture, delivery, and how the team works.

How I work

I validate the design of each solution before building it, and I build it with TDD and planned edge cases. Agents do much of the work. The decisions stay with me, and nothing is done without evidence. My teams use the same six-step process, from ticket to merge.

  1. Define scope

    MeI define what is in scope and what is not.

    The agentsThe agents read the request, search every involved repository, and return the open questions.

  2. Validate the design

    MeI spend the most time here. I challenge options, validate product decisions with the PM, and remove assumptions before code is written.

    The agentsThe agents propose options with tradeoffs and list every assumption they made. They help turn the selected approach into a spec.

  3. Plan the work

    MeI define the files, tests, exclusions, and contracts between repositories. I set the permissions and TDD requirements for each workstream.

    The agentsThe agents work from repository briefs in their own worktrees. They follow the agreed API and database contracts.

  4. Build with TDD

    MeI require every piece to start with a failing test for the right reason. I make edge cases part of the plan, including empty, zero, negative, duplicate, limit, and error paths.

    The agentsThe agents implement and review each task separately. They do not change a test just to make it pass.

  5. Verify with evidence

    MeI review the UX and decide whether the result is ready.

    The agentsThe agents test end to end in QA, the browser, or a real iPhone, and leave screenshots, database state, and GIFs as evidence.

  6. Review and merge

    MeI authorize each merge explicitly and decide whether a rollback is needed after reviewing logs.

    The agentsThe agents perform an exhaustive review before human review and monitor logs after the merge.

Automatic safety net

Hooks run on every agent command to enforce the rules before mistakes reach shared environments.

agent $ git push origin main

BLOCKED: git push to 'main' (current branch 'main').
Changes to master/main need explicit authorization from the human.
Ask the user to run this command themselves with `!`.

Principles

A lab for testing ideas with real products

I do the design, the backend, and the app myself, and I use these products to test ideas before I bring them to a team.

Pila Today screen with the readiness score (sample data)

Pila

iOS · SwiftUI · Beta

Pila reads Apple Health and recommends how much to train based on your own history, calculated on the phone rather than against averages.

PadelBump match detail with the score

PadelBump

iOS · SwiftUI + Python backend · In App Store review

PadelBump brings live professional padel to iPhone through Live Activities, with a backend that checks matches every 10 seconds.

TorneosPadelUy map of tournaments

TorneosPadelUy

iOS and web · Expo, React Native and Supabase · Live

TorneosPadelUy covers amateur padel tournaments across Uruguay, with one Expo and React Native codebase for iPhone and web.

Public engineering controls

I use these tools every day. Several of them enforce rules from the AI standard I contributed to.

Compare notes on AI adoption in engineering

I am open to conversations about AI adoption, architecture, and technical leadership.

Most of my work lives in private client repositories. © 2026 Santiago Hernández