AI Product Engineer · Remote · Serbia

I build software that
businesses actually run on.

Eight years of shipping web products, e-commerce systems and business apps. For the last years I have built and operated my own AI SaaS products end to end: architecture, integrations, billing, testing, releases and support.

Available for remote roles and contracts · English C1 · TypeScript, Next.js, Supabase, Cloudflare, Stripe, Claude and OpenAI APIs

GitHub LinkedIn Email me

1,284paying customers of MasterBot in 2025

10,000+Google Play downloads of Psaltir

8,000+students taught to build software

200+websites and online stores since 2018

Selected work

Products I own and systems I built for clients. Client names are shown only where the client agreed.

Technical lead · contract · 2026–2027

Vivatra: single-tenant platform to multi-tenant SaaS

Vivatra (Belgrade) develops food formulations with its Product Design Engine, built on Django, Next.js, PostgreSQL and AI agents. I lead the transition of the platform into a multi-tenant SaaS while their in-house engineer writes the code.

Technical audit and transition plan, tenant isolation with row-level security, per-tenant encryption, audit log and AI cost accounting per tenant
Stripe subscriptions, onboarding funnel and admin, CI, staging, observability and runbook
Mentoring the engineering team twice a week, landing pages and technical SEO

DjangoNext.jsPostgreSQLStripeCI/CD

Own product · live SaaS · founder and builder

Moonya AI: social media on autopilot

Generates, reviews, schedules and publishes brand content on nine networks. The user only approves.

Structured AI generation with quality review, task-specific model selection and provider fallback
Queued media processing with retries, recovery and duplicate prevention
Auth, subscriptions, credits, analytics and multi-network publishing

TypeScriptCloudflare WorkersQueues · R2SupabaseStripeClaude · OpenAI

moonya.ai Case study

Client system · 2026 · designed and built solo

Order-to-courier automation for a Shopify retailer

Takes orders from two Shopify stores and ships them cash-on-delivery through couriers in Bosnia and Montenegro, with fiscal receipts for Serbia in progress.

Webhooks with HMAC verification and dedupe, phone and address normalization, duplicate order detection with an explanation
Courier adapters: API, automated portal and Excel import; shipment status machine; AI address assistant with a daily cost cap
Over 1,000 automated tests, Playwright end-to-end, separate test database, CI

Next.jsSupabase · RLSShopify APIClaudeVitest · Playwright

Kovin Humano SrceLinija podrške · anonymous chat, AI first contact, volunteers

Client system · 2026 · designed and built solo

24/7 support line for a humanitarian association

Anonymous chat for people in distress, built for Kovin Humano Srce. AI handles first contact, volunteers take over.

Crisis check before and after every AI reply, emergency numbers always visible, quick exit
Request goes to all volunteers, the first to accept takes the conversation; PWA panel with push and email
Admin for the coordinator, monthly report, AI answer evaluation before launch

Next.jsSupabaseAnthropic APIPWA

VajbAgentAI coding agent · browser IDE · VS Code extension

Own product · agentic coding · built 2026, currently paused

VibeAgent: AI coding agent with IDE and VS Code extension

I built an agent backend, a browser-based IDE and a VS Code and Cursor extension, and ran it with my students before pausing the product.

Streaming agent loops with tool calling: files, search, diffs, web access, command execution
Configurable human approval for edits and commands
Sessions, usage accounting, billing, OAuth integrations and object storage

TypeScriptVS Code APICloudflareClaude · OpenAI

Own product · live SaaS since 2024

MasterBot: AI marketing assistant

Content, design and automation tools for small businesses in the Balkans. 1,284 paying customers in 2025.

AI workflows for text, images and video, credits and usage accounting
Stripe billing, integrations and product analytics

ReactTypeScriptSupabaseStripe

master-bot.ai

Own product · mobile · shipped

Psaltir: React Native app with 10,000+ downloads

Orthodox prayer book for Android with media, reminders, notifications, favorites and monetization.

React Native and Expo, release builds and store listing managed end to end
Ads and app-ads.txt, privacy and terms pages, crash-free updates

React NativeExpoGoogle Play

Google Play

How I work

I use AI coding tools every day. What makes the result production-grade is everything around them.

Scope before code

I turn a business need into requirements, data model and a plan with milestones, and I say what is out of scope.

Tests that run

Unit, database and end-to-end tests on every change, a test database separate from the working one, CI green before release.

Releases in stages

Local, staging, production. Secrets never in the repo. Cutover plans for live systems with real orders.

I own it after launch

Monitoring, error reports and user feedback drive the next change. I answer when something breaks.

Stack

What I ship with, in production, today.

TypeScriptNext.js · ReactReact Native · ExpoNode.jsSupabase · PostgreSQL · RLSCloudflare Workers · Queues · R2Vercel · NetlifyStripeShopify Admin APIAnthropic · OpenAI APIsAgents and tool useVitest · PlaywrightDjango · Python (leading)WordPress · WooCommerce

Teaching

No Code Balkan, co-founder and mentor

Since 2023 I have taught more than 8,000 students to build apps and automations. Many shipped their first product to the App Store or Google Play. Udemy “Highest Rated” instructor.

Background

YourSalesWorld, founder since 2018

More than 200 websites and online stores on WordPress and Shopify, plus custom CRM and booking systems, for clients in Serbia and abroad. Faculty of Economics, Novi Sad, Business Information Systems.

Let's talk

Open to remote engineering roles and contracts where one person needs to own a product from scope to release.

nemanja.lakic1@gmail.com LinkedIn GitHub Download CV (PDF)