Eli Benhaim
Senior Full Stack Developer · TypeScript, Node.js, SvelteKit / React · AI Products on the Cloudflare Edge
Zichron Yaakov, Israel · Israeli citizen · Remote or hybrid · eli@leads-mania.com · linkedin.com/in/eli-benhaim · smartcogai.com · Code samples on request
Summary
Full-stack developer, nine years. Builds web products from the architecture down to the tests and the docs. The last three years have been AI products on Cloudflare Workers: a multi-agent platform for group therapy, a multi-tenant chat-assistant platform with paying clients, and a live booking system for a hotel. Writes the architecture rules down, works from checked plans, and hands clients source code they own.
Seeking a full-time senior engineering role on an AI product team.
Skills
- Full stack: TypeScript, Node.js, Express, Hono, REST, WebSockets, server-side rendering, SvelteKit / Svelte 5, React / Next.js, Tailwind, shadcn, Astro, Web Components (Shadow DOM), Vite library builds
- Cloudflare and edge: Workers, Durable Objects (WebSocket Hibernation, alarms, SQLite), D1, KV, R2, Containers, service bindings and RPC, AI Search, Workers AI, Realtime
- AI and agents: multi-agent orchestration, tool calling, structured output, RAG (pgvector, Cloudflare AI Search), prompt design, Vercel AI SDK, multi-provider LLMs (Anthropic, OpenAI, Google, Mistral, Groq, Workers AI), speech-to-text (Deepgram)
- Data: PostgreSQL, Prisma, Drizzle, SQLite (FTS5), Zod, append-only ledgers and approval workflows, event-driven side effects
- Security, auth and privacy: HMAC, AES (Web Crypto), JWT, replay protection, magic-link login, Better Auth, two-factor, prompt-injection prevention, PII detection, HIPAA-aware design
- Internationalisation: Hebrew-first and RTL layouts, 13-language UI, staff-editable translations
- Integrations and tooling: Stripe, Cal.com v2, Tranzila, CardCom, Payload CMS, headless WordPress, RezStream, Sentry, Puppeteer, Wrangler
- SEO and lead generation: technical and programmatic SEO, directory sites, WordPress (custom themes and tables), custom CMS, PHP
Experience
Product Engineer — Independent (full-stack, TypeScript / Node)
Designs and builds complete products end to end, on client engagements and independent projects.
GroupClimate — real-time multi-agent platform for group therapy (groupclimate.app)
Platform for clinician-led group sessions in chat, video and in person, built on Cloudflare.
- Six services: four Cloudflare Workers and two SvelteKit dashboards, connected only by service bindings. Nothing internal is reachable from the public internet.
- Multi-agent layer on Durable Objects and the Vercel AI SDK. Models, prompts and tools are rows in D1, so behaviour changes without a deploy.
- Real-time session backend over WebSockets (Hibernation, alarms, DO SQLite). Chat and live-transcribed voice share one pipeline, with a safety check before anything is shown. Audio is never stored.
- Personal identifiers never reach the server. PII detection in English, Hebrew and Russian runs in Cloudflare Containers before anything is saved.
- Deterministic end-to-end tests cover every service-to-service call.
- Written architecture rules, a dated build ledger and generated code snapshots keep the docs matched to the code.
SmartCog AI — multi-tenant AI assistant platform (smartcogai.com)
Custom AI chat assistants that install on any website with one script tag. Seven services (backend, edge-auth Worker, D1 mirror, widget, CDN component library, nudge framework, tool service), all built and run solo. Two paying clients and six live demos across music, retail, health products, hospitality and tax.
- Multi-tenant backend in Express, Prisma and PostgreSQL with pgvector. Eight LLM providers behind one factory, each tenant on its own API key. Tools are defined in the database and compiled from JSON schema to Zod when a request comes in.
- Three-layer auth for the widget: HMAC and AES on the client, signature checks in a Cloudflare Worker, double-HMAC with replay protection and one-minute JWTs on the backend.
- Found that UI components could send free text to the model from the browser. Replaced that with server-owned action templates, payload allow-lists and per-component URL checks.
- RAG from ingest to citation. Cited items become typed UI cards through structured generation against per-category schemas.
- Embeddable widget as a Shadow DOM Web Component, 13 languages with full RTL. A conversation orchestrator sequences typed text and card mounts, and 13 versioned UI components load at runtime from a CDN.
- Engagement framework where each site declares its nudges as data (triggers, conditions, priorities, memory across visits for abandoned-cart recovery), with an arbiter so the assistant never talks over itself or the user.
- Seven-phase client implementation playbook. New clients go live in about a week.
- Six live demos: a band's ticket and merch assistant, an earphones shop with cart and checkout in the chat, a hotel room-booking assistant, an Israeli employment-tax advisor with 20+ tools,, a medical-cosmetics shop, and a supplement brand's assistant that explains the product line and sells it in the chat. Links on the home page.
Hotel Beit Maimon — online booking system (Zichron Ya'akov)
Hebrew-first, right-to-left booking for a boutique hotel. Delivered under a written agreement with 195 itemised deliverables, full source handover and a two-year warranty.
- Booking page and staff dashboard in SvelteKit on Cloudflare Workers, D1 with Drizzle, KV sessions. Runs on the free plan.
- Custom theme for the hotel's booking engine (RezStream): about 1,200 lines of CSS over the vendor's own class names, so the engine runs inside an iframe and looks like part of the page while keeping multi-room stays, extras, registration and payment.
- Built a full availability engine against the RezStream API first (unit-level availability, rate coverage, arrival and departure rules, reservation matching on a cron), then cut the app down to what only it could do, in eight planned and checked steps.
- Staff edit text in every language, booking rules (same-day cutoff in the hotel's timezone), the embed button and access, all from a dashboard behind magic-link login. The one-tag embed button follows the host site's language switch.
Selected client work
- Architected a rule-extraction system that turns Israeli legislation into deterministic eligibility calculators, with AI-assisted extraction, expert review and citation tracking.
- Designed an AI subscription and content-discovery solution for a publication with 250K+ readers.
- Produced B2B portal architecture proposals comparing three stacks with pricing and recommendations.
FindRecoveryCenter.com — directory of substance-abuse recovery centers
Year-long project built with one other developer to generate leads for a US client.
- Co-built a national directory of 26,000 US drug and alcohol treatment facilities, with listings collected from public web sources and structured into pages that convert visitors by phone or form.
- Built it on custom WordPress themes with a purpose-designed database table for the listing data. The site reached 2,000–3,000 visitors a month and is still live.
Lead-generation directory sites
Built and ran directory and lead-generation sites as sole developer.
- Built and operate SureWindows.com (replacement windows) on a programmatic location-page approach. It still draws 4,000+ visitors a month.
- Moved to data-driven directory sites when search-engine rules changed, covering the full cycle: data collection, build, content structure, search optimization and lead capture.
Web Developer — content and lead-generation studios, Kyiv, Ukraine
Developer at content studios building traffic and lead-generation sites for home-services and retail niches.
- Built, as part of the development team, a programmatic SEO platform in PHP (Yii and Kohana) that generated a page for every US city, county and state from content templates, producing sites of over a million pages.
- Sourced and assembled the US locations database behind the platform, and generated the SEO URLs and sitemaps from it.
- Built and maintained sites on the platform and on WordPress for locksmith, roofing, replacement-window and POS-system markets. A POS-systems site reached about 26,000 visitors a month and locksmith sites generated up to about 7,000 calls a month.
- Worked with the business side to find contractors to buy the leads, tying the engineering work directly to revenue.
Education
Bachelor's degree, Computer Science — National Technical University of Ukraine "Kyiv Polytechnic Institute" (NTUU KPI), Faculty of Informatics and Computer Engineering · 2013 – 2017
Languages
English (native) · Hebrew (conversational) · Russian (basic)