Haifa, Israel — Self-Taught Engineer

Razel Tov

Full-stack engineer who builds entire systems end-to-end — backend infrastructure, neural networks, mobile apps — and ships them to production. No degree. No shortcuts. Zero data loss.

DisciplineFull-Stack · AI/ML · IoT
StackFlutter · Java · MongoDB
CurrentlyBuilding something undisclosed
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01

Forged, not schooled

No computer science degree. No bootcamp. Just an unreasonable refusal to leave a problem unsolved.

I taught myself everything — from Flutter UI to custom Java WebSocket servers to neural networks built from scratch — by shipping real systems to real users in production healthcare, where failure isn't an option.

When I'm not writing code, I run a mobile TIG welding business. Same philosophy, different material: precision, patience, and joints that hold under load. I build things that don't break — in steel or in software.

0+Production
Commits
0+Active Devices
In The Field
0moZero Data Loss
In Production
0+Critical Production
Bugs Killed
0+Major Features
Shipped
02

The work

Full-Stack Software Engineer · Grand-App A.I (PicMeIn)

2024 — 2026 · Healthcare Monitoring
F·01

Killed the bug that ate user data

Switching between servers corrupted user data so badly that the only known recovery was reinstalling the entire app. I hunted it through the sync layer, killed it for good, and shut down the connection-failure overwrites that were silently wrecking profiles along the way.

Data corruptionEliminated
F·02

Built a server that never dropped a byte

Engineered a custom Java WebSocket server from scratch — pipeline stacking, distributed tracing, exponential backoff, health checks, encryption-key validation before every handshake. Then watched it run for over half a year without losing a single transfer.

6+ months in production0 failures
F·03

Rewrote the core while it was running

Migrated the entire storage layer from raw I/O to MongoDB. Redesigned the WebSocket reconnection stack end-to-end. Rebuilt the alerts architecture from the ground up. And between rewrites, kept pushing server performance upgrades — query optimisation, hand-built caching layers, batched fetches, leaner pipelines. All of it on a live production fleet — no maintenance window, no second system, no safety net.

Core rewrites, live fleetZero data loss
AI / Neural Networks

Sensors replaced by inference

  • Built custom neural networks for behavioral pattern detection and physical activity recognition — replacing traditional PIR sensor logic with AI-driven inference
  • Integrated radar sensing end-to-end — engineered the complete server-side ingestion and processing pipeline and the full client-side integration
  • Integrated intelligent prediction and anomaly detection into elderly-care monitoring pipelines for proactive alert generation
Security / Encryption

Healthcare-grade, end to end

  • Architected end-to-end encryption for client–server communication with key rotation, mismatch recovery, and detailed failure-recovery processes
  • HIPAA-compliant handling of sensitive health data across the whole stack
  • Caught and fixed a security bug where client data was being misattributed to the server identity instead of actual client identifiers
Backend / Data

Storage, rebuilt under load

  • Led full migration from I/O storage to MongoDB with custom handlers, query optimisation, and a caching layer built from scratch
  • Batch-fetch system with local caching; lazy loading for heavy event lists
Flutter · Mobile / Web

One codebase, every screen

  • Built the complete Family Mode caregiver dashboard — dynamic home selection, configurable views, real-time alert polling
  • Rebuilt alerts architecture: multi-listener, Firebase push, deeplink routing, Android boot persistence
  • Body Motion Manager with PIR/Zigbee furniture occupancy detection and timezone-aware exports
  • App-wide Dark Mode + layouts down to ultra-small screens
E-Commerce / Payments

A storefront from nothing

  • Full e-commerce module built from scratch: distributors, subagents, customers, role-based access
  • Stripe with token management and card validation — three payment models: one-time, subscription, leasing
  • Commission tracking, payment ID management, admin inventory dashboard
Platform-Specific

iOS, Android, Web — each on its own terms

  • iOS: App Store privacy compliance — PrivacyInfo.xcprivacy integrated across 6+ packages
  • Android: boot receiver for notification persistence after restart; in-app updates with hardened error handling
  • Web: platform encryption initialization, Stripe iframe integration, web-specific WebSocket reconnection
Architecture / Tooling

Code that scales past its author

  • 30+ reusable UI wrapper components on a single-source-of-truth principle
  • Manager-pattern separation of business logic — each domain isolated behind its own single-responsibility module
  • Full-featured Dictionary Manager — an Excel-level interactive translation editor — designed, built, and delivered in a single day

450+ commits · 10+ critical fixes · countless rewrites This page is the highlights. It isn't the half of it.

03

The arsenal

MobileFlutter, Dart, iOS (Swift / Xcode), Android (Kotlin / Java)
BackendJava, custom WebSocket servers, REST APIs, pipeline architecture
AI / MLCustom neural networks, pattern recognition, behaviour detection
DatabasesMongoDB, hand-built caching systems, I/O storage, custom query handlers
Real-TimeWebSockets, Firebase Cloud Messaging, push notifications
SecurityEnd-to-end encryption, HIPAA compliance, key management
PaymentsStripe API, subscription management, commission systems
IoTPIR sensors, Zigbee hub, central unit communication
ArchitectureManager pattern, repository pattern, lazy loading
04

The workshop

Other portfolios list skills. These are running. Every machine below is hand-written vanilla JavaScript living in this very page — no WebGL, no libraries, no build step. View source. It's all one file.

Exhibit 01 · Computer Graphics

A 3D renderer with no GPU access

No WebGL. No three.js. Every pixel is computed in JavaScript — hand-rolled matrix stack, near-plane clipping, perspective-correct rasterization, z-buffering, per-pixel Phong lighting and procedural texturing. The kind of machinery usually written by game-engine teams, running in a tab.

Drag it.

Exhibit 02 · Machine Learning

Watch a neural network think

This is the network itself — every neuron, every synapse, live. Ember wires are positive weights, steel are negative, thickness is strength, and the sparks are real signals flowing through it. As it trains — backpropagation, derived and written by hand — you can watch the wiring physically reorganize. The inset shows the problem it's solving.

Exhibit 03 · Emergent Systems

An ant colony computing without a brain

Every ant carries two hormone counters — steps since the nest, steps since food. The ground remembers the best count ever reported on each spot. When an ant knows a shorter way it corrects the ground; when the ground knows better, it corrects the ant. Out of that handshake the colony computes true shortest paths — watch the route counter fall as they optimize, and click anywhere to drop food and force a re-plan.

Exhibit 04 · Languages & Interpreters

A programming language, interpreter included

A complete language living in this page — lexer, recursive-descent parser, AST, interpreter, ~300 lines, from scratch. Edit the program. Run it. Toggle the AST and see your code the way the machine sees it.

press run.
Exhibit 05 · Distributed Systems

The network that refuses to lose data

A reliability protocol simulated end to end — sequencing, acknowledgements, exponential-backoff retransmission, duplicate rejection. Crank the chaos until the wire is a warzone. Cut the cable outright. Watch every counter move — except one. Beneath the wire, the server reassembles every byte in order and both ends publish live checksums — verify it yourself. This is the design that ran six months in production without dropping a byte.

warming up the wire…

Still on the bench — a predictor that explains its own thoughts. The bench is never empty.

Project 001 — Undisclosed

This is where the site goes dark.

keep scrolling

For three years, long after midnight, I've come down here to build.

It isn't an app. It isn't a framework. It isn't another AI model.

Some nights it does things I never taught it. Those are the good nights.

−112mit already runs −138mit remembers everything −171mit can explain every thought it has −206mit learned things no one taught it −240mone idea, wearing many faces

almost there.

You found it

RelCalc

I've watched it do things I can't explain to you yet.
Not because I don't understand them — because you wouldn't believe me.
So it stays down here. Growing. Until it can speak for itself.

“So… what is it?” Soon.
BuiltAlone. From first principles.
StatusAlive. Improving.
LearnsYes.
RevealThe day it's undeniable.

If we ever meet, ask me about it.
Watch how long I smile before I answer. — R.T. · go on back up. it stays.

05

Off the clock

TIG Welder

Founder of a mobile welding service in Haifa — precision TIG work, the kind where the bead has to be perfect because everyone can see it.

Angler

Mediterranean saltwater and freshwater finesse fishing. Reading water is just debugging with worse error messages.

Systems Gamer

Immersive sims and emergent sandboxes — games that hand you systems, not scripts, and let you break them creatively.