Ibuildsoftwarethatshipstoproduction.
I’m Isaac Cohen, an 18-year-old full-stack developer in Miami. I’ve built a WhatsApp-first marketplace with 21,000 lines of production code, a live algorithmic trading platform serving paying subscribers, and a mobile SAT prep app — all shipped, tested, and running.
Miami Beach · Full-stack
Production systems, shipped and running.
Marketplaces, trading platforms, and mobile apps — built end to end.
Live physics — go ahead, touch it
Every strand is simulated in real time. This is the kind of thing I build.
Skills
Full-stack, from database to deploy.
I build complete systems — not just interfaces. Databases, APIs, background workers, payment flows, and the frontend on top. Every project below runs in production or is production-ready.
Languages
- TypeScript
- Python
- JavaScript
- SQL
- C++
- Java
Frontend & Mobile
- React
- React Native
- Next.js
- Expo
- Tailwind CSS
- CSS Modules
Backend & Data
- Node.js
- PostgreSQL
- Supabase
- SQLite
- Docker
- REST APIs
Integrations & Tools
- Stripe
- WhatsApp Business API
- OpenAI API
- Kalshi API
- Git
- Vercel
Projects
Things I’ve built and shipped.
Real systems, not tutorials. Each one was designed, built, tested, and deployed by me — backend, frontend, database, and integrations.
Sitters Over FL↗
A WhatsApp-first babysitter marketplace and operations platform for South Florida.
Sole developer — design, backend, frontend, database, integrations
~21k
Lines of code
140
Source files
177
Tests passing
18
DB migrations
I built the entire platform end to end. The public website — designed and built by me — explains the service, the founder's story, pricing, FAQs, and sitter opportunities. Behind it sits a full operations system: parents start on WhatsApp and either chat conversationally or open a private, expiring booking form; the backend collects children, location, schedule, rate, and care needs, then deterministically matches sitters by availability, service area, language, and driving ability. The WhatsApp bot sends private job offers, builds an immutable parent shortlist with sitter photos, and confirms bookings with fee-link delivery. A protected owner dashboard — effectively a lightweight CRM — handles bookings, sitters, escalations, conversations, and dispatch.
What I built
- →Database — PostgreSQL via Supabase: booking state machine enforced in both TypeScript and SQL, RPCs with expected-state checks and row locks against concurrent updates, 18 migrations
- →Website — custom responsive design in CSS Modules (no UI framework), public pages plus protected owner dashboard
- →Backend — idempotent, resumable webhook processing; encrypted expiring booking links; signed HttpOnly admin sessions
- →WhatsApp bot — Meta Business Cloud API; AI extracts booking details from natural language (EN/FR/ES) with schema-validated outputs barred from authoritative decisions
Engineering highlights
- →Formal booking state machine enforced in TypeScript and PostgreSQL
- →Idempotent, resumable webhook processing — duplicate WhatsApp/Stripe events never repeat side effects
- →AI extracts booking details from natural language but is schema-validated and barred from authoritative decisions
- →Encrypted, expiring booking links; signed HttpOnly admin sessions; RLS with no browser-facing policies
Automatrade↗
Automated copy-trading platform for sports prediction markets.
Founder & sole engineer — architecture, backend, bots, billing, DevOps
11
Live bots
30+
Discord commands
<10s
Signal-to-order
Paying
Subscribers
I founded and built Automatrade from scratch. It's a copy-trading platform: algorithmic trading bots publish their picks, and subscribers' accounts automatically mirror those trades on Kalshi, a regulated prediction-market exchange. Everything runs through Discord — subscribers join the server, pick their bots with slash commands, connect their Kalshi API keys, set risk limits (unit sizes, stop losses, max orders), and receive every trade as a real-time Discord message with a one-click link to the market. A web dashboard at automatrade.app shows live P&L, bot lineups, and account controls. Billing runs on Stripe subscriptions with weekly itemized statements. The whole system — signal ingestion, order placement, Discord delivery, billing, health monitoring — runs on a DigitalOcean server I manage, deployed through an automated CI/CD pipeline.
Engineering highlights
- →11 live bots, single-digit-second signal-to-order latency
- →Stream-only signal ingestion with automatic polling fallback
- →Kalshi circuit breaker, SQLite busy-retry, durable fan-out queue
- →Owner-alert watchdog: Discord DM within 5 minutes on sustained degradation
SAT Practice App
Tinder-style SAT Math practice for iOS and Android.
Sole developer — app, question engine, UI
1,925
Questions
397
Visual assets
33/33
Tests passing
iOS + Android
Platforms
A mobile SAT Math practice app with a swipe-based interface: a question appears, the student reveals the answer, swipes right for the next one. Covers 1,925 practice questions across Algebra, Advanced Math, Problem Solving & Data Analysis, and Geometry — 1,461 multiple-choice and 464 numeric entry, tiered easy/medium/hard, with 397 visual assets. Free with ads plus paid ad-removal. All 33 tests passing; simulator debug build working.
Engineering highlights
- →Swipe-based UX: question → answer → swipe for next
- →1,925 questions across 4 domains, 3 difficulty tiers
- →397 visual assets for diagram-based questions
- →Offline-first with AsyncStorage; no backend required
Isaac
Full-stack developer
Miami, Florida
“Young, hungry, and shipping.”
About
Young, hungry, and shipping.
I’m Isaac, an 18-year-old full-stack developer based in Miami Beach. I’ve been building real software since I was 14 — from a WhatsApp-first marketplace with 21,000 lines of production code to a live algorithmic trading platform serving paying subscribers.
I’m looking for an entry-level engineering role where I can learn from strong professionals and contribute from day one. I ship fast, test my work, and take ownership of what I build.
Production-minded
I build systems that run in production — with tests, monitoring, error handling, and the operational discipline real users depend on.
Full-stack
Database to deploy. I design schemas, write APIs, build interfaces, and ship the infrastructure that holds it together.
Fast learner
I pick up new stacks quickly and go deep fast — from WhatsApp's Business API to Kalshi's trading API to React Native.
Owner's mindset
I've founded and run a real product with paying subscribers. I think about the business, not just the code.
Contact
Let’s talk.
I’m looking for an entry-level software engineering role in Miami — South Beach, Brickell, or mainland. If you’re hiring and want someone who ships, I’d love to hear from you.
01
Say hello
Send me a message about the role, the team, or what you're building. I read everything personally.
02
Talk projects
Happy to walk through any project here in detail — architecture decisions, trade-offs, what I'd do differently.
03
Meet
I'm in Miami Beach and available for calls, video chats, or in-person meetings around Miami.
Why me
- ✓Full-stack: TypeScript, React, React Native, Python, PostgreSQL
- ✓Production experience: real users, real money, real uptime requirements
- ✓Available immediately for entry-level engineering roles in Miami
Prefer email? isaac@cohenwebsolutions.com
Based in Miami Beach — open to roles across Miami and remote.