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Guvanch D.

Backend Developer5+ years of experience

Node.js / TypeScript / Go

Building scalable backend systems, distributed services and AI-powered applications. Experienced in system architecture, database optimization, real-time applications and production infrastructure.

  • Ashgabat, Turkmenistan
  • Open to remote and office roles
  • Full-time / Part-time
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Portrait of Guvanch D.
StatusOpen to new backend roles
years of commercial software development, since 2021
5+
online services on e.gov.tm — I was one of two backend engineers
40+
OAuth 2.1 server that lets Claude and ChatGPT work inside the CRM I architected
MCP
file streaming through the FIFA API at Turkmenportal
2.5 GB

Selected work

Systems I designed, built and ran in production

Four projects that best show how I approach backend engineering — what problem each one solved, how it is structured and why it was built that way.

01Microservices · CRM · AI

aseller — CRM for Amazon Sellers

A CRM and analytics platform for Amazon sellers and their teams — products, suppliers, orders, shipments, freelance requests, chats and AI tools — built as three Node.js services: REST API, background queue and real-time gateway.

Key decisions

  • Long AI jobs as asynchronous tasks with long-polling
  • Access control in layers, not in one place
  • Row locks in a fixed order for shipments
  • Read cursors instead of a row per reader
  • Node.js
  • Fastify
  • BullMQ
  • Socket.IO
  • PostgreSQL
  • Redis
  • OAuth 2.1
  • MCP
Read case study
02GovTech · Integrations

e.gov.tm — Government Services Portal

Turkmenistan's unified portal for government services. I was one of two backend developers on the platform, which grew to more than 40 online services by early 2024.

online services on the platform by early 2024
40+
backend developers on the team, including me
2

Key decisions

  • Each external system behind its own integration module
  • Payment status changes inside database transactions
  • Go for the service layer
  • Go
  • PostgreSQL
Read case study
03AI · Retrieval-augmented generation

RAG Knowledge Base

A multi-tenant knowledge base in launch-tools, Launchist's Go platform. Teams upload documents, which are embedded into PostgreSQL with pgvector, and chat with them through streamed, source-grounded answers.

Key decisions

  • pgvector instead of a separate vector database
  • Namespaces as the unit of isolation and retrieval
  • Ingestion as its own pipeline with bounded concurrency
  • Streaming answers with conversation history
  • Go
  • Echo
  • LangChain (Go)
  • PostgreSQL
  • pgvector
  • Redis
  • WebSocket
Read case study
04Mobile product · AI · Sync

Finlens — Personal Finance App

A personal finance app I designed and built on my own: Flutter app, Fastify backend and AI features on Gemini — voice-to-transaction, a finance assistant chat and a voice copilot for the app's forms.

voice-parsing eval cases per language
~7,000
languages in the AI evaluation suite
5
automated backend tests
254

Key decisions

  • Optimistic concurrency with a global change cursor
  • Never trust model output
  • Resilient AI calls
  • Measure the AI instead of guessing
  • Flutter
  • Node.js
  • Fastify
  • PostgreSQL
  • Redis
  • Gemini API
Read case study

More projects

Other things I've built

ERP analytics, messaging and e-commerce platforms, news monitoring, an AI video SaaS, AI agents and an Android app built on my own.

  • E-commerce · Go backend

    Rowshen — E-commerce Platform

    One Go backend for the Rowshen store — website, admin panel and mobile app: catalog, orders, store locations and content, organized as independent domain modules.

    • Single REST API for website, admin panel and mobile app
    • Catalog organized by categories, collections, seasons and product types
    • Orders and their line items written inside database transactions
    • Go
    • Echo
    • GORM
    • PostgreSQL
    • JWT
    • Swagger

  • SaaS · AI video · Billing

    Yepic AI — Avatar Video Platform

    Backend of Yepic AI, a SaaS for AI video avatars: accounts, a public API, usage-based billing and orchestration of external AI services. Built at Launchist.

    • FastAPI backend on PostgreSQL (SQLAlchemy, Alembic) and MongoDB (Beanie)
    • Usage-based billing with Lago and Stripe, webhooks for invoices, wallets and subscriptions
    • Public API with keys gated by subscription plan
    • Python
    • FastAPI
    • PostgreSQL
    • MongoDB
    • Redis
    • Lago
    • Stripe
    • Vertex AI

  • ERP analytics · Algorithms

    Fund-Flow Analytics for Logo Tiger ERP

    An analytics service on top of a company's Logo Tiger ERP database that reconstructs where money came from and which projects it funded — across cash, bank, current-account and stock movements.

    • Reads Logo Tiger movement tables and custom SQL views in MSSQL
    • Four linking strategies: transfers (virman), parent reference, source reference and FIFO allocation
    • Graph traversal that attributes amounts along money-flow chains by their bottleneck
    • Go
    • Echo
    • GORM
    • MSSQL
    • Logo Tiger
    • WebSocket

  • SaaS · Messaging

    WhatsApp Campaign Platform

    A multi-tenant B2B platform for WhatsApp Business campaigns through Twilio: organizations, contacts and lists, message templates with WhatsApp approval, and bulk sending.

    • Organizations, users, contacts, contact lists and message templates
    • Template creation and WhatsApp approval requests through the Twilio Content API
    • Bulk sending through a pool of 10 goroutines with job and result channels
    • Go
    • Echo
    • PostgreSQL
    • Supabase Auth
    • Twilio
    • GCP Secret Manager

  • Data ingestion · Media monitoring

    News Monitoring Platform

    A national news aggregation and monitoring platform: collects articles from registered news sites in Turkmen, Russian and English, filters them by keywords and reports coverage.

    • Scheduled RSS ingestion from registered sites with keyword filtering
    • Language detection for Turkmen, Russian and English content
    • Source discovery through Google News (Serper API) with a moderation queue for new sites
    • Go
    • Echo
    • GORM
    • PostgreSQL
    • RSS
    • Serper API

  • E-commerce · ERP integration

    ERP-Backed E-commerce

    One e-commerce backend running two clothing stores — Ojuk Bujuk and Alfinur — directly on top of each client's ERP database in MSSQL, with Nuxt admin panels.

    • AdonisJS (TypeScript) API reading products, prices and discounts straight from ERP tables in MSSQL
    • Phone sign-up with one-time codes; SMS sent by a phone gateway connected over Socket.IO
    • JWT access and refresh tokens with separate guards for customers and admins
    • AdonisJS
    • TypeScript
    • MSSQL
    • Socket.IO
    • Nuxt
    • PM2

  • Retail · ERP integration

    POS System for Logo Tiger ERP

    A point-of-sale backend integrated with Logo Tiger ERP, keeping products and prices synchronized in real time.

    • Integration with Logo Tiger ERP through the Logo Objects REST API
    • Real-time product and price synchronization
    • Sales processing
    • Node.js
    • Sequelize
    • PostgreSQL
    • Redis
    • Logo Objects REST API

  • AI · Agent orchestration

    Multi-Agent AI Platform

    A backend for defining AI agents, assigning them tasks and running them together as crews through an API.

    • Agent management
    • Task management
    • Crew orchestration with CrewAI
    • Python
    • Django
    • CrewAI

  • Mobile product · AI · Learning

    AI Dictionary for Android

    A native Android app for learning English words, built on my own: capture a word from any app, get an AI-written article with translations, then learn it with spaced repetition and AI-generated exams.

    • Capture words from anywhere: text-selection menu in any app, shared images with crop and AI OCR, and a screenshot watcher with a floating bubble
    • AI word articles — explanation, Russian and Turkmen translations, examples — with text-to-speech
    • Two AI providers behind one interface: Anthropic and Gemini, with the user's own encrypted API key
    • Kotlin
    • Jetpack Compose
    • Hilt
    • Room
    • Ktor
    • WorkManager
    • Anthropic API
    • Gemini API

Also built

  • Wakant — jobs portalBackend and admin panel with admin and agency roles, resumes, chat, FCM push notifications and PDF export.Express · Sequelize · PostgreSQL · Nuxt
  • Consular registration portalGovernment portal for citizens abroad: document uploads, passwordless email-OTP login, JWT refresh and an admin review workflow.Go · Echo · PostgreSQL
  • ERP mobile dashboardsBackends for mobile apps showing company cash, bank and account balances from an ERP database, with scheduled checks, FCM push and a WebSocket feed.Go · MSSQL · gocron · FCM
  • Abraýly Mebel — furniture store APICategory tree, product attributes, search in three languages and CI/CD to a systemd service.Go · Echo · PostgreSQL · GitHub Actions
  • Identity service (in progress)Foundation of a unified identity service: access and refresh tokens with rotation, revocation and row-level locking.NestJS · Sequelize · PostgreSQL
  • Menzil — maps admin panelAdmin panel for a maps and routes app: points and routes on the map, weather, user suggestions, Turkmen and Russian UI.Nuxt · Vuetify · MapLibre

About

How I work

I'm a backend developer with 5+ years of commercial experience (since 2021), specializing in Node.js, TypeScript and Go. I build REST APIs, microservices, distributed and real-time systems, and AI-powered products.

I contributed to e.gov.tm, Turkmenistan's unified government services portal. My strongest area is data: SQL, query optimization, transactions, locking and concurrency. I deploy and operate what I build — Docker, Linux servers and production environments.

  • System architecture

    Splitting systems by load profile and failure domain — APIs, workers, real-time gateways and scheduled jobs.

  • Data & performance

    Schema design, indexing, transactions and locking in PostgreSQL. Queries shaped around the hot paths.

  • Production infrastructure

    Docker, Linux, nginx, HTTPS, PM2 and systemd. From first commit to a running, backed-up server.

  • Review & mentoring

    Code review, mentoring junior developers and owning projects end to end.

Experience

Where I've worked

5+ years of commercial experience: started on the frontend in 2021, then moved to backend.

  1. Turkmenportal · Backend Developer

    Jan 2025 — Present

    Backend APIs and the production infrastructure they run on.

    Node.js · Fastify · nginx · PM2 · systemd

    • FIFA API with streaming delivery of files up to 2.5 GB
    • Designed and configured the production infrastructure
    • Backend API for a multilingual media library
    • Set up nginx, HTTPS, PM2 and systemd

  2. Launchist · Backend Developer

    Jan 2024 — Dec 2024

    Software studio building backends for client SaaS and AI products, in Go and Python.

    Go · Echo · Python · FastAPI · PostgreSQL · Supabase · MongoDB · Redis · Cloud Run

  3. e.gov.tm · Backend Developer

    Jun 2022 — Dec 2023

    Turkmenistan's unified government services portal.

    Go · PostgreSQL

  4. Nesip Etsin · Frontend Developer

    Sep 2021 — May 2022

    Frontend platform development with Vue and Nuxt.

    Vue 2 · Nuxt 2

Stack

Tools I use in production

Grouped by what they're for. No percentages — the projects above show how each one is used.

  • Backend development

    • Node.js
    • TypeScript
    • Go
    • Python
    • NestJS
    • Fastify
    • Express
    • Echo
    • Gin
    • Django

  • Databases & storage

    • PostgreSQL
    • MySQL
    • MS SQL
    • MongoDB
    • Redis
    • SQLite
    • pgvector

  • Infrastructure & DevOps

    • Linux
    • Docker
    • Docker Compose
    • nginx
    • CI/CD
    • PM2
    • AWS EC2
    • Sentry

  • Architecture & engineering

    • Microservices
    • REST API
    • Distributed Systems
    • Clean Architecture
    • Dependency Injection
    • Concurrency
    • Database Optimization
    • Transactions & Locking
    • Real-time Systems

  • AI & integrations

    • RAG
    • LangChain
    • CrewAI
    • Anthropic API
    • Gemini API
    • Vector Search

  • Additional technologies

    • Vue
    • Nuxt
    • Flutter
    • Kotlin
    • WebSocket
    • Socket.IO
    • ffmpeg
    • HLS

Contact

Let's build something together

Open to remote and office roles, interesting engineering challenges and freelance collaborations.

Send Email
Email
guvanch.d.1999@gmail.com
Telegram
@guvanchd
GitHub
github.com/guvanch999
Location
Ashgabat, Turkmenistan