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Portrait of Adelson Aguasvivas

Software engineer · New York

Adelson
Aguasvivas.

I build software end to end.

Four-plus years building secure, data-intensive systems at scale, from petabyte pipelines at Amazon to platform engineering at Coachable. Harvard CS, 2021.

After hours: games, tools, and a dominoes scorekeeper on the App Store.

Email Resume GitHub ↗ LinkedIn ↗

55 PB

of privacy-sensitive data secured at Amazon

$1.3M

in quarterly savings from pipeline optimization

200+

engineers coached into top tech roles

12+

projects built end to end, idea to deploy

2

native languages. Everything I build ships in both

01

Experience

Download resume (PDF) ↓

May 2023 · Present · New York, NY

Coachable · Software Engineer

Education startup helping engineers land roles at top tech companies.

  • Engineered and scaled the coaching platform and data systems behind a 95% placement rate into roles at Google, Amazon, Meta, and Microsoft.
  • Designed analytics pipelines for student performance and hiring outcomes: 3x faster reporting, 40% better data accuracy.
  • Coached 200+ engineers through CS fundamentals and 1000+ mock interviews, resulting in hundreds of offers.

July 2021 · January 2023 · Cambridge, MA

Amazon · Software Development Engineer, Alexa

High-volume, privacy-sensitive data pipelines powering Alexa.

  • Led data deletion and retention across 700M+ objects and 55 PB of S3, saving $1.3M quarterly through lifecycle automation in Python and Java.
  • Security Lead for the team: resolved 80+ risks, including 2 critical org-wide escalations, via IAM hardening and encryption enforcement.
  • Owned GDPR and CCPA deletion across petabyte-scale datasets with zero violations; 300+ on-call tickets resolved at 99.9% SLA.

Summer 2019 · Urbana-Champaign, IL

University of Illinois Urbana-Champaign · Research Engineer, DREU Program

One of about 40 students selected nationally for the DREU research program.

  • Built an automated grading and hint-generation system for large CS courses with LLVM, C/C++, and Python: 10x grading throughput.

2017 · 2021

Harvard University · A.B. Computer Science, 2021

Secondary in Ethnicity, Migration and Rights. Spanish citation.

Honors: Forbes 30 Under 30 Scholar · HSF Scholar · Tuskegee Airmen Scholar · NSA Scholar · Dominican Day Parade Scholar

02

Selected work

Six projects in more depth: infrastructure, an NBA front-office console, real-time multiplayer, a game engine, a data pipeline, and a shipped iPhone app.

Ledgerline

Live

An edge-native event-stream API with exactly-once writes and a tamper-evident hash chain.

  • Exactly-once appends via idempotency keys reserved for the stream’s lifetime
  • SHA-256 hash chain whose verification pinpoints tampering, including truncation
  • 68 tests running inside the real Workers runtime, not mocks
Cloudflare WorkersDurable ObjectsD1TypeScriptHono
Read more → Visit ↗ GitHub ↗
The Cap Room: An NBA front-office console: cap sheets, a trade machine whose verdicts explain themselves, player evaluation.

The Cap Room

Live

An NBA front-office console: cap sheets, a trade machine whose verdicts explain themselves, player evaluation.

  • One pure TypeScript engine for the 2023 CBA rules, zero UI imports, 43 unit tests
  • The Rule Ledger: every check the engine ran, pass or fail, with the arithmetic in plain English
  • Trades serialize into the URL, so any proposal is a shareable link
Next.jsTypeScriptReactVitest
Read more → Visit ↗ GitHub ↗
Capi: Dominican dominoes, online with your people: 2v2, capicúa, trancao, no accounts.

Capi

Live

Dominican dominoes, online with your people: 2v2, capicúa, trancao, no accounts.

  • A pure, zero-dependency rules engine with 62 tests, shared by web and mobile
  • Real-time play over Supabase Realtime: pick a name, share a link, play
  • Authentic Dominican rules: capicúa, trancao, 2v2 con tu frente
Next.jsTypeScriptSupabase Realtime
Read more → Play ↗ GitHub ↗
SWARMGEDDON: A twin-stick survival shooter on a hand-rolled engine: fixed timestep, spatial hash, fully deterministic.

SWARMGEDDON

Live

A twin-stick survival shooter on a hand-rolled engine: fixed timestep, spatial hash, fully deterministic.

  • 60 Hz simulation decoupled from render, with interpolation
  • One seeded PRNG drives everything: a seed replays a run exactly
  • Synthesized audio engine, zero sound assets
TypeScriptPixiJSWebGLCapacitorPWA
Read more → Play ↗ GitHub ↗
Invicto: Draft nine players across all six World Baseball Classics and try to go 7-0. Ships in four languages.

Invicto

Live

Draft nine players across all six World Baseball Classics and try to go 7-0. Ships in four languages.

  • A real data pipeline: Wikipedia rosters joined with the Chadwick and Lahman databank, validated at build time
  • Monte-Carlo-calibrated difficulty: an elite lineup goes 7-0 only 2 to 5% of the time
  • Four locales with build-failing drift tests; anonymous daily stats, no accounts
TypeScriptViteCloudflare D1
Read more → Play ↗ GitHub ↗
Anota: A Dominican dominoes scorekeeper for iPhone: both teams on one screen, capicúa and all.

Anota

App Store

A Dominican dominoes scorekeeper for iPhone: both teams on one screen, capicúa and all.

  • Shipped on the App Store with a Pro in-app purchase
  • Over-the-air updates, haptics, shareable score cards
  • Bilingual with type-enforced dictionary parity
ExpoReact NativeTypeScriptStoreKit
Read more → App Store ↗ GitHub ↗

03

How I build

Habits that show up in every project I own.

01

Everything is tested

Ledgerline runs 68 tests inside the real Workers runtime, not mocks. Conuco’s game core holds 126. If it isn’t tested, I don’t consider it done.

02

Deterministic by design

My games route all randomness through one seeded generator, so a seed reproduces a run exactly. That makes daily challenges fair and bugs reproducible.

03

Difficulty is calibrated, not guessed

The draft games tune their balance with Monte Carlo simulation. A top-tier run should win 2 to 5% of the time, and the build fails if the numbers drift.

04

Saves never break

Versioned save files, additive-only migrations, defaulted fields. A save from day one still works on the latest build.

05

Bilingual by construction

Spanish and English dictionaries share one enforced type, so a missing translation is a build error instead of a bug report. This site works the same way.

06

AI at the edges, engines at the core

I use LLMs where they help: drafting, suggesting, tailoring. A deterministic engine owns the outcome, with local fallbacks so nothing breaks when the API is down.

04

After hours

I build games and small tools on my own time. Four of them are live in the browser right now.

Play now

SWARMGEDDON

A twin-stick survival shooter on a hand-rolled engine: fixed timestep, spatial hash, fully deterministic.

▶ Play →

Invicto

Draft nine players across all six World Baseball Classics and try to go 7-0. Ships in four languages.

▶ Play →

Flawless

Draft five anime characters and survive a seven-battle tournament. The whole game is 83 KB.

▶ Play →

Capi

Dominican dominoes, online with your people: 2v2, capicúa, trancao, no accounts.

▶ Play →

Free, in the browser, no accounts.

The Veil · El Velo: A playable Rawls experiment: legislate from behind the veil, then be born into your own society.

The Veil · El Velo

Private build

A playable Rawls experiment: legislate from behind the veil, then be born into your own society.

  • The simulation was built and verified headless before any UI existed
  • A Monte Carlo gate proves balanced rulesets beat both extremes
  • Spanish-first, native-ready with Capacitor
ReactTypeScriptZustandCapacitor
Read more →
Conuco: A cozy Caribbean farming game where the point is reviving the pueblo, not min-maxing the farm.

Conuco

Private build

A cozy Caribbean farming game where the point is reviving the pueblo, not min-maxing the farm.

  • Game logic never imports the renderer: one sacred seam, 126 tests
  • Versioned saves with additive-only migrations and a backup slot
  • A kept-terms glossary keeps Dominican vocabulary untranslated in every language
TypeScriptPixiJSVitestCapacitor
Read more →

More projects

Everything else, including what’s still in progress.

The System

Private build

An interview-prep RPG that became a job-search cockpit: deterministic engine, AI only at the edges.

ReactViteClaude APITailwind
Read more →

Living Todo OS

Private build

A personal life OS that answers one question: what’s the single best thing to do right now?

Next.jsTypeScriptClaude APITailwind

Flawless

Live

Draft five anime characters and survive a seven-battle tournament. The whole game is 83 KB.

TypeScriptViteCloudflare Workers
Play ↗ GitHub ↗

Coherente · Bite the Bullet

In development

A roguelike of moral consistency. You never lose for being wrong, only for contradicting yourself.

ReactTypeScriptZustand

Hype Room

In development

The iOS app for a real sneaker shop: drops, grails, and a catalog built to swap to Square in one file.

ExpoReact 19TypeScript

Earlier work

Portrait of Adelson Aguasvivas

05

About

I studied computer science at Harvard, then spent two years at Amazon working on the pipelines that kept 55 petabytes of Alexa data secure and compliant. Now I’m at Coachable, where I build the platform and coach engineers preparing for interviews.

I’m Dominican and grew up between Spanish and English, which is why everything I build ships in both. Outside of work I build games and small tools, usually with some piece of home in them: dominoes, baseball, a little coastal pueblo. It’s how I stay sharp, and honestly, it’s fun.

If you’re hiring, my resume is above, and I’m happy to walk through any of these projects in as much detail as you want.

06

Get in touch

Email is the fastest way to reach me. I answer everything.

Email me Resume

[email protected]

GitHub ↗ LinkedIn ↗