Buenos Aires --:--:--

Marcos Maceo

Software engineer, ex-founder. Havana → Dubai → Buenos Aires.

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01 — About

  1. HAVHavana · 23.1° Nborn, studied CS
  2. DXBDubai · 25.2° Nfounded a company
  3. EZEBuenos Aires · 34.6° Shome, for now

I’m Marcos. Born in Havana, built a company in Dubai, and now learning Buenos Aires one cuadra at a time.

I studied computer science at the Universidad de La Habana. Since June 2021 I’ve been at Nethermind, on Ethereum and Starknet infrastructure. Along the way I founded Token Fleet in Dubai and built a few products of my own. I like the parts of a system nobody notices until they break.

Spanish at home. English at work. I switch without warning.

02

What I build the quiet parts

Payments, auth and backends, and the infrastructure under them. Follow one request through, and stop anywhere.

Who’s asking

OAuth2 and JWT for identity, rate limits at the door, and anomaly detection for traffic that looks almost right.

  • OAuth2
  • JWT
  • Rate limiting
  • Anomaly detection

auth ▸ token verified · under the limit · nothing odd

What they want

Typed services in TypeScript and Go, REST or gRPC between them, PostgreSQL underneath and Redis where it earns its place.

  • TypeScript
  • Node.js
  • Go
  • gRPC
  • REST
  • PostgreSQL
  • Redis

api ▸ validated · routed · one transaction

Where it gets serious

Stripe payments, KYC onboarding, idempotency keys and double-entry ledgers, and webhook reconciliation, so a retry never charges anyone twice.

  • Stripe
  • KYC
  • Idempotency
  • Double-entry ledgers
  • Webhooks

ledger ▸ key seen before · no double charge · books balanced

Ethereum & Starknet

At Nethermind: QA and DevOps for the Nethermind execution client across L1 and every supported L2, benchmarks and regression suites, and the early days of Juno, a Starknet client.

  • Ethereum
  • L2s
  • Starknet
  • Client QA
  • DevOps
  • Benchmarks

node ▸ client synced · benchmarks run · release gated

Before it ships, and after

Test-first, CI that gates releases, Docker on AWS and GCP, and Prometheus and Grafana, so failures show up on a graph before they turn into an incident.

  • Test-first
  • CI/CD
  • Docker
  • AWS
  • GCP
  • Prometheus
  • Grafana

ci ▸ tests green · deploy out · dashboards quiet

Somebody has to be awake when the webhook doesn’t come back.

03

Projects running, led, and shelved on purpose

At Nethermind

June 2021 — present

  • QA and DevOps for the Nethermind execution client, from L1 through every supported L2. Benchmarks and regression suites that gate releases, and Prometheus and Grafana across the node fleets.

    • Ethereum
    • L2s
    • Benchmarks
    • CI/CD
    • Prometheus
    • Grafana

  • I led the initial Juno team and started the implementation of Nethermind’s Starknet client, setting its early architecture and engineering practices.

    • Starknet
    • Architecture
    • Team lead

  • Worked on Sedge, mapping the infrastructure behind one-command L1 node and validator deployments across execution and consensus clients.

    • Ethereum
    • Validators
    • DevOps

My own

Founder · since April 2024

Each went from zero to production-ready. None took on customers, and that was a call, not an accident: when the market or the numbers weren’t right, I shelved it rather than put people on something I couldn’t stand behind.

  • Payment flows, KYC onboarding and a transactional ledger, designed around emerging-market regulation. I pitched it to partners and investors myself.

    • Payments
    • KYC
    • Ledger
    • Regulation

  • A multi-tenant Go and PostgreSQL backend, REST and WebSocket, for point of sale, kitchen display and QR ordering, with an idempotent transaction ledger, Stripe payments and webhook reconciliation.

    • Go
    • PostgreSQL
    • WebSocket
    • Stripe
    • Webhooks

  • An applied-AI product, taken to production-ready and then parked, for the same reasons.

  • Among them, a billing and quota engine on a credit ledger, driven by payment webhooks, that keeps balances straight across concurrent jobs and retries.

    • Idempotency
    • Ledger
    • Webhooks

Earlier

2019 — 2021

  • Backend services and REST APIs for cross-border checkout and logistics: payment-gateway and card integrations, webhook reconciliation and idempotent order settlement.

    • REST
    • Payments
    • Webhooks
    • Idempotency

  • Led engineering on a multi-chain wallet: key management, transaction construction and signing, and the APIs between the mobile app and the backend.

    • Key management
    • Signing
    • APIs
04

Off the clock which is kind of the point

A

Squash

plays
FRONT WALL T

The T is home. Every shot is about getting back to it.

B

Basketball

watches
Shot clock
24 s · counting down
Home---
Tip-off · BA21:00
Away---

NBA from Buenos Aires means tip-off at 9 pm or 3 am. I watch both.

C

Table for two

cooks · with his wife

House menu

Buenos Aires · two cooks, one kitchen

  1. Arroz congrí×2Havana. Non-negotiable.
  2. Something from the Dubai years×2To be decided.
  3. Whatever the verdulería had×2Buenos Aires, most nights.

2 covers · no reservation

Cooking with my wife. The best meeting on the calendar.

D

Buenos Aires on foot

walks
PLAZA DE MAYO AV. 9 DE JULIO Río de la Plata
22cuadras walked≈ 2.2 km

The best way to learn a city is one cuadra at a time. Still learning this one.

05

Now lately

Building
Small tools and side projects. Mostly because it’s fun.
Studying
M.S. in Data Science at Universidad Austral. In progress.
Learning
Buenos Aires, one barrio at a time. Every colectivo line, eventually.
Stories

A few are being written. Deciding which ones make the cut.

Updated · Sept 2026

06 — Hello

Say hi.About food, the city, code, anything.

marcosmaceowork@gmail.com