I will build or fix n8n workflows and API integrations

N
nikolarados
N
nikolarados
Nikola R
build or fix n8n workflows and API integrations
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build or fix n8n workflows and API integrations
Full Screen
Full Screen
build or fix n8n workflows and API integrationsbuild or fix n8n workflows and API integrationsbuild or fix n8n workflows and API integrations

About this gig

I'm a backend developer, so I build n8n workflows the way I'd build any integration that touches real data: every run is logged, failed steps retry, and a webhook that arrives twice won't create a second order or invoice.


Typical jobs:

  • connect forms, CRM, email, Google Sheets, Stripe or Shopify through webhooks and APIs
  • call APIs that have no n8n node, with OAuth2 or API keys
  • write code nodes in JavaScript when the built-in nodes aren't enough
  • add an AI step (OpenAI or Claude) to sort, summarize or draft replies
  • fix workflows that fail, time out or create duplicates
  • set up self-hosted n8n with Docker and Postgres

I keep three of my own n8n systems on GitHub: a PDF request for quote turned into a priced Excel quote, a booking backend for Vapi and Retell voice agents, and payment webhooks pushed to a POS. Together they have 31 automated tests that run on every change.


Message me first with what should happen and which tools are involved. I'll reply with a short plan and the package that fits.

  • AI Model Frameworks & Tools

    • Retell AI
    • Vapi AI
    • n8n
    • OpenAI ChatGPT
    • Anthropic Claude

  • Platform

    • Custom
    • n8n

  • Type

    • Data syncing
    • Email automation
    • CRM workflows
    • E-commerce order
    • Voice & Calling

  • Automation Integration Points

    • Website
    • Google Sheets
    • Slack
    • Email
    • Shopify

  • Programming Language

    • C#
    • JavaScript
    • TypeScript

Get to know Nikola R

Nikola R

Senior backend developer, APIs and n8n automation

  • FromSerbia
  • Member sinceOct 2026

  • Languages

    English, Serbian
I've been writing C# for over six years, mostly on the backend. Right now I work on a smart-metering platform: .NET 10 services that talk over Kafka, with SQL Server and Cassandra behind them. Before that I built Azure backend services for a tax platform, and spent four years on a logistics company's TMS, ERP and CRM (ASP.NET Core, Angular, SQL Server). I started in 2018 in application support. On Fiverr I take on API work, bug fixes in existing .NET apps, integrations and n8n automations. I find the cause before I change code, and I explain what I changed in plain words.

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