Hey, there

Portrait of Nikita Sergeev

// go developer

{ go, kafka, postgres, redis }

$ whoami

→ nikita sergeev — go backend engineer

open to offers

Hire me
based in
Belgrade, Serbia · remote
status
open to remote work
↓ scroll
(01) about who's behind the code
hi, i'm nikita_

I'm a Go developer who builds backends from scratch — from an EdTech platform to a B2B product of 6 microservices that 15 companies switched to. I care about modular architecture, async communication via Kafka and APIs the frontend never has to ask about.

Download CV github.com/n1x9s
3.5+
years in Go backend
15
companies on a product I built
1000
RPS at peak
(02) stack go · data · infra

Tools I ship with

~/n1x9s — zsh stack.go 
$ cat stack.go
package main

var stack = map[string][]string{
    "lang":  {"go", "gin", "gorm"},
    "api":   {"rest", "websocket", "openapi"},
    "data":  {"postgres", "redis", "kafka"},
    "infra": {"docker", "linux", "gitlab-ci"},
}

func main() { ship(stack) } 
// → 200 OK
toolbox 12
  • Go
  • Gin
  • GORM
  • PostgreSQL
  • Redis
  • Kafka
  • REST · OpenAPI
  • WebSocket
  • JWT · OAuth 2.0
  • Docker
  • GitLab CI/CD
  • Claude API

> now learning Kubernetes

(03) works 2023 — 2026

Selected works

  • 01

    Kontinental · 2025 — now

    Center — B2B platform

    In-house B2B product of 6 Go microservices — CRM, projects, knowledge base, helpdesk, staff and HR. 15 client companies replaced their scattered tools with it.

    • Async communication via Kafka — up to 10,000 events a day with idempotent processing
    • Deploys cut from 30 to 2 minutes with GitLab CI/CD, releases ~3× more often
    • Redis cache for hot queries: p95 response time 400 → 50 ms
    • 50+ REST endpoints with Swagger docs, JWT-based RBAC and OAuth 2.0
    • Go
    • Gin
    • Kafka
    • PostgreSQL
    • Redis
  • 02

    ViewTrain · 2023 — 2025

    ViewTrain

    EdTech platform for AI-powered tech interview prep. I built the whole Go backend solo: 8 domains, ~1,000 users, up to ~150 concurrent sessions.

    • Real-time interview over WebSocket: 4 stages from picking a track to the final score
    • AI answer review via Claude API with streaming — first feedback in ~3 s
    • 82 REST endpoints, ~15 PostgreSQL tables, passwordless login with passkeys
    • Go
    • WebSocket
    • PostgreSQL
    • Claude API
  • 03

    ViewTrain · Pro

    Code Runner Sandbox

    Algorithm task checker: user code runs in isolated Docker containers and gets a verdict for every test. ~500 solutions checked.

    • Per-test verdicts instead of a single pass / fail
    • The same engine powers the refactoring mode of the paid Pro plan — ~300 subscribers
    • Go
    • Docker
    • PostgreSQL
  • 04

    Kontinental · Center

    Employee Onboarding

    A new hire's portal account, email, GitLab and Telegram access are set up automatically — ~40 minutes of manual HR and IT work per person gone.

    • 10+ hires a month → 6+ hours of HR and IT time saved every month
    • OAuth 2.0 integrations with Yandex 360 and GitLab
    • Go
    • OAuth 2.0
    • Yandex 360
    • GitLab
(04) contact replies within 24h

available for work

Let's build
something.

Say hi
  • email sernekit77@gmail.com
  • telegram @nikitabackdev
    open
  • github github.com/n1x9s
    open
  • linkedin in/n1x9s
    open