Eleazar.

AI automation engineer.

I’m Eleazar. I build AI agents, n8n workflows and Amazon SP-API tools that take the daily checks off your team.

Seller Central knows everything. It doesn’t tell you what to fix first.

What needs doing today, worst first.

  1. Out of stock, still selling. Products with orders and no stock. Always at the top, because they lose sales every day.
  2. Needs shipping to Amazon. What to send and how many days are left to cover the season ahead.
  3. Stock Amazon is not selling. Units Amazon holds but won’t sell, flagged so someone checks Seller Central.
The seller dashboard I built. It opens on today’s problems, worst first: out of stock and still selling, needs shipping to Amazon, stock Amazon is not selling. Brand, products and money figures are blurred for the client.

A seller dashboard I built for a US outdoor brand on Amazon. SP-API, n8n, Supabase and React. Client build, in delivery. The first pre-season purchase order has already gone out through it.

Read the case study

More Amazon systems I’ve built.

Amazon SP-APIorders · returns · financial eventssettlements · inventoryFBA shipments · feesn8n, one workspaceabout 45 workflowsdaily · hourly · gap-fillshared Reports API looprequestpolldownloadparseuntil readyClient inventory systemUS · Canadaemail alerton failure
How the sync engine runs, simplified.

Amazon SP-API Sync Engine

For
An Amazon FBA business selling in the US and Canada.
What it does
Brings orders, returns, financial events, settlements, inventory, FBA shipments and fees into their inventory system, daily and hourly. If a run is missed, it catches up.
Runs on
About 45 n8n workflows in one workspace.
Status
Client build, live. Walmart built and staged on the same pattern.

Every sync emails the moment it fails, so a quiet morning means it ran.

Read the case study
AbeBooksBiblioAlibrislistings scannedabout 2,000each morningbuying rulesabout 700 passpriced under its six-month averagelive check, each survivorprice · condition · seller locationreal browser for bot-protected shopsmargin per bookafter postage and Amazon feesdaily buy list6 to 8 booksinside the budget
How one morning’s run narrows, simplified.

Used-Book FBA Sourcing Engine

For
A used-book Amazon FBA seller.
What it does
Scans about 2,000 listings on AbeBooks, Biblio and Alibris each morning, opens every survivor live for price, condition and seller location, counts postage and Amazon fees, and writes a buy list inside the daily budget.
Runs on
Node.js, and a real browser for the shops behind bot protection.
Status
Client build, in delivery. 230 automated checks guard every change.
Read the case study

I also build AI agents and n8n workflows for lean teams.

AI agents and n8n workflows.

Tap a row to see the real build.

  • n8n canvas of the DeductiveLabs agent flow: a webhook and a chat trigger, a product manager agent, an incident summary agent, and a switch that routes to four specialist agents

    Part of the DeductiveLabs engine. A product manager agent reads the issue, a summary agent condenses it, and a switch hands it to one of four specialist agents, each with its own OpenAI model.

In my clients’ words.

Eleazar brought the vision into reality. I wasn’t sure how the automation was going to work but he showed us that everything was possible. He works really quick.

AI Automation, Image Generation

Jan 2026, 5 stars, verified on Upwork

Reliable, Committed to Quality

He has deep knowledge in workflow automation. His technical background helped the project to be more than I envisioned.

n8n Multi-Agent Framework Design

Dec 2025 to Feb 2026, 5 stars, verified on Upwork

Committed to Quality, Solution Oriented, Detail Oriented

Great experience working with this developer. Responsive, detail-oriented, and delivered high-quality work on time. Excellent communication throughout. Highly recommended.

Workflow Automation (Asana, Zapier, HubSpot)

Oct to Nov 2025, 5 stars, verified on Upwork

Reliable, Collaborative, Clear Communicator, Accountable for Outcomes

Read every review on Upwork (opens in a new tab)

Where I’ve worked.

Windows and Azure systems in enterprise IT from 2012 to 2026. Now building AI automation full time.

  1. Aug 2026 to presentBook-Sourcing EngineFreelance · Used-book Amazon FBA seller (Upwork)Details
    • Building a sourcing engine that scans about 2,000 used-book listings each morning across AbeBooks, Biblio and Alibris, and ends with a daily buy list that fits the client’s budget.
    • Every surviving listing is opened live for its current price, condition and seller location. Postage and real Amazon fees are inside the margin before a book can be recommended.
    • 230 automated checks pin behavior before any change ships; a deliberate gate keeps the scraping engine from being edited casually.
    • Phased, milestone-based engagement. Sourcing failure modes the client caught by hand are now guarded by automated checks.

    Skills: Node.js, Web Scraping, Chrome DevTools Protocol, Amazon FBA

  2. Apr 2026 to presentAI DM Agent (Instagram to GoHighLevel)Freelance · AVA (Tamara)Details
    • Shipped the full agent: 24/7 Instagram DM automation that classifies inbound intent, handles objections and generates context-aware replies with Claude.
    • Implemented two-way Instagram Graph API integration handling verification handshake, inbound message events and outbound automated replies.
    • Routes confirmed bookings into GoHighLevel with contact deduplication, pipeline opportunity creation and team alerts.
    • Runs end to end without human input. It escalates to a human only when the conversation actually needs one.

    Skills: n8n, Claude, Instagram Graph API, GoHighLevel, AI Agents, Webhooks

  3. Nov 2025 to presentAutomation Specialist, Amazon SP-API and SourcingFreelanceDetails
    • Built automations against Amazon’s Selling Partner API: LWA authentication, request throttling, pagination and the asynchronous Reports API.
    • Live sales and inventory dashboards with re-order alerts; inbound-shipment and order-status workflows synced to the inventory system.
    • Two-stage LLM product-sourcing bot: strict brand / UPC / MPN / SKU matching plus SOP rules, with Apify supplier scraping and Keepa pricing. Buy / no-buy verdicts are delivered to Slack with sourced reasoning.
    • Added logging and monitoring so failures are easy to track and debug in production.

    Skills: n8n, Amazon SP-API, Python, OpenAI, Apify, Keepa

  4. Sep to Nov 2025Creative IntelligenceSanlava (e-commerce and social brand)Details
    • Designed a “creative intelligence” workflow that scrapes ads, UGC and reviews from TikTok, Instagram, Facebook and Google.
    • Structured data into Notion databases (Organic Posts, Ads, Reviews, Trends, Hook Bank), a single source of truth for creative ideas.
    • Used OpenAI and Gemini to generate hooks, UGC briefs and static ad prompts based on scraped data and custom scoring rules.
    • Automated weekly runs, scoring and QA so the marketing team gets fresh, ready-to-use creative insights without manual research.

    Skills: n8n, Apify, Notion, OpenAI, Gemini, UGC

  5. 2012 to Jul 2026System Administrator, Windows and Azure CloudEnterprise InfrastructureDetails
    • Managed large fleets of Windows Server environments with strong focus on uptime, security updates and compliance.
    • Automated patching and reporting via PowerShell and Azure Update Manager, keeping systems consistently up to date at scale.
    • Troubleshot complex L3 issues across VMware, networking, storage and backups in production environments.
    • Worked with global teams to plan changes, communicate risks and document runbooks for stable, repeatable operations.

    Skills: Windows Server, Azure, PowerShell, VMware, Patch Management

Tools I use. Automation: n8n, Make, Zapier. AI and agents: Claude, Claude Code, OpenAI, Gemini. Amazon: SP-API, Keepa API. Full stack: Supabase, React, Node.js, Python, Netlify. Data and CRM: Airtable, Notion, HubSpot, GoHighLevel. Scraping and APIs: Apify, custom APIs.

Fixed price, per milestone.

You get a written scope and a fixed price for each milestone. You sign off before I build anything, so there are no surprise invoices.

  • The specialty

    Amazon System Build

    $900 to $2,400 per build

    Covers
    • SP-API sync workflows for orders, inventory, financials and returns
    • Live seller dashboards with re-order alerts
    • Sourcing and buy-decision tools
    • Runs on your accounts, credentials stay yours
    • Handoff doc and recorded walkthrough

  • AI Agent and Workflow Build

    $600 to $1,800 per build

    Covers
    • AI customer agents that know your knowledge base
    • n8n and Make workflows
    • Internal AI assistants that answer with citations
    • Data pipelines
    • API and CRM integrations

  • Maintenance and Growth

    $200 a month

    Covers
    • Up to 5 hours of updates a month
    • Monitoring and small fixes
    • Priority support
    • A monthly summary

Each build is split into fixed-price milestones. Smaller job? Hourly consults and fixes from $15 an hour.

How a build goes.

  1. Day 1

    Call and audit

    A 30-minute call. I look at your current setup, ask where the hours go, and point out what is worth automating first.

  2. Days 2 to 3

    Written scope

    Deliverables, timeline and a fixed price per milestone, in writing. You sign off before I start.

  3. 1 to 3 weeks

    Build

    I work in your tools, so the handoff is clean. You see working pieces every few days, with a weekly check-in.

  4. Final week

    Handoff

    It runs on your accounts, with full documentation and a recorded walkthrough. Yours to keep.

Questions.

Not sure which fits? We’ll work it out on the call.

Book a call (opens in a new tab)

Tell me what you check every morning.

In 30 minutes, I’ll tell you plainly if I can automate it and what it would take. If it’s outside my lane, I’ll say so.

Book a call (opens in a new tab)

I’m taking new projects, and I usually reply within 24 hours.

Fixed price per milestone. Runs on your accounts. Code, credentials and docs stay yours.

© 2026 Eleazar Sebastian Martinez. Built in React, with entirely too much n8n.