Your systems don't talk to each other.
I architect the fix.

I'm Sinisa Devcic — a systems architect who designs integration architectures, builds production systems from hardware to cloud, and keeps critical infrastructure running. For companies where downtime means lost revenue. One engineer. Full ownership. Zero agency overhead.

Start a Conversation See Case Studies

130+ systems shipped • 16 industries • 25+ years in production • Based in the Netherlands

Sinisa Devcic — Systems Architect at DynConnect

Sinisa Devcic

Systems Architect & Lead Engineer

130+
Systems Shipped
25+
Years in Production
16
Industries Served
99.9%
Uptime SLA
What I Do

I solve four types of problems

🔌

Connect Your Systems

When your ERP, webshop, and invoicing run in silos, you lose orders, double-enter data, and miss invoices. I architect integrations that eliminate manual work and make your systems operate as one.

  • NetSuite ↔ PrestaShop, WooCommerce, Shopify
  • Peppol e-invoicing & compliance
  • Payment gateway integration
  • Custom API design & real-time data sync
One client's order processing went from 4 hours of manual work to fully automated — after I connected their NetSuite ERP to their e-commerce platform.
📡

Build Your Product

You have a product idea but need someone who can own the entire technical stack — from hardware prototyping to mobile apps to cloud backend. I take products from concept to market, making every architecture decision along the way.

  • Web & mobile apps (React, React Native)
  • IoT devices (BLE, NFC, firmware, PCB design)
  • Real-time video & communication (WebRTC, LiveKit)
  • AI-assisted features & automation
Built a complete IoT product — BLE beacon hardware, firmware, mobile apps, cloud backend — from whiteboard to shipping in under 12 months.
⚙

Run Your Infrastructure

Production infrastructure isn't a commodity. One misconfigured cluster, one missed alert, one unpatched server — and your business stops. I architect, deploy, and maintain infrastructure with 99.9% uptime because I understand what's actually running on it.

  • Docker, Kubernetes, GCP, Linux
  • CI/CD pipelines & zero-downtime deployment
  • Monitoring & alerting (Prometheus, Grafana)
  • Security hardening & ISO 27001 compliance
Managing 80+ servers and Kubernetes clusters for a 200+ employee e-commerce company — continuously, for over a decade.
🔄

Modernize Your Legacy

Your legacy system works — but it's brittle, undocumented, and blocking every new initiative. I migrate systems to modern architectures without disrupting operations, because I've done it enough times to know where the risks hide.

  • Legacy system migration without downtime
  • Desktop-to-web & cloud migration
  • Database optimization & re-architecture
  • Technical debt assessment & reduction
Migrated decade-old desktop applications to cloud platforms — zero downtime, zero data loss, full backward compatibility.
Case Studies

Real problems. Architecture decisions. Measurable outcomes.

Helloprint e-commerce platform — NetSuite PrestaShop integration
Enterprise Integration

E-Commerce Platform — Unifying a 200+ Employee Operation

The Problem

A growing e-commerce company serving multiple European markets had disconnected systems — NetSuite ERP, PrestaShop webshop, and financial processes all running in separate silos. Orders required manual re-entry, invoice reconciliation took days, and the infrastructure of 80+ production servers couldn't scale with the business.

Architecture Decision

Key decision: Chose event-driven architecture over batch syncing — real-time order processing instead of nightly imports. This required idempotent message handling to prevent duplicate transactions, but eliminated the processing lag that was costing the business sales.

Order processing fully automated. Finance reconciliation runs without manual intervention. 80+ production servers managed on GKE with Galera, Ceph, and ProxySQL. AI helpdesk handles IT requests with 100+ tests. 10+ year client relationship, including Head of IT role (2016–2017).
GKEKubernetesNetSuiteSuiteScriptPrestaShopGaleraCephProxySQLPrometheusDockerCI/CDClaude API
ParkAlert IoT BLE parking beacon hardware and mobile app
IoT Product Development

ParkAlert — From Whiteboard to Shipping Hardware Product

The Problem

A startup needed a smart parking solution — BLE beacons that detect vehicle presence and alert drivers via mobile app. They had an idea and funding, but no prototype, no technical team, and no clear path to production.

Architecture Decision

Key decision: Selected BLE over WiFi and cellular for the beacons. Lower power consumption and lower unit cost, with sufficient range for parking scenarios. Traded off range for 2+ year battery life per beacon — critical for a product that needs to work maintenance-free outdoors.

Full product shipped in under 12 months. Apps on both stores. Product evolved into a family of 4 IoT products (ParkAlert, ZippAlert, BellAlert, DoorLink). Patent filed (WO2025089955). Business case discussions with major Dutch retailer. Hardware manufactured in Hong Kong.
BLEFirmwareSwiftJavaReact NativeFirebaseYellowbrick APIFlowbird API
ZippLabs smart video doorbell WebRTC NFC access platform
Real-Time Platform

ZippLabs — Smart Video Doorbell & Access Control

The Problem

A hardware company needed a complete smart access platform — video doorbell with real-time calling, NFC-based access control, and a management dashboard. Required sub-second video latency and reliable unlock in all weather conditions.

Architecture Decision

Key decision: Chose LiveKit over raw WebRTC — reduced time-to-market by months while maintaining sub-200ms video latency. Selected NFC over QR codes because NFC works reliably in rain, direct sunlight, and with gloved hands — real conditions for an outdoor product.

Working smart access platform with video intercom at doorlink.io. Sub-second call connection. Reliable NFC unlock across weather conditions. Patent filed (WO2025089955). Hardware manufacturing pipeline established with Hong Kong supplier. Business case discussions with major Dutch retailer (Intergamma).
WebRTCLiveKitNTAG 424 DNAReact NativeExpoNode.jsPostgreSQLDocker
Blackware print production automation pdfToolbox prepress
Industrial Automation

Blackware — Print Production Automation at Global Scale

The Problem

Print and packaging companies worldwide need automated PDF preflight, correction, and production tracking. Manual prepress checks are slow, error-prone, and don't scale. The industry requires strict compliance with PDF/X and PDF/A standards.

Architecture Decision

Key decision: Invested in understanding PDF specification internals rather than treating pdfToolbox as a black box. This allowed building custom preflight profiles that catch industry-specific issues other systems miss — preventing costly reprints.

Running across 900+ installations worldwide. Years of reliable operation. Prepress automation eliminated the majority of manual checking.
pdfToolboxPDF/APDF/XBarcode SystemsTrack & Trace
Blndr interactive green screen photo booth platform
Interactive Experiences

Blndr — Real-Time Green Screen & Interactive Photo Platforms

The Problem

An innovative photo marketing company (Mr. GreenScreen, later Blndr) needed a complete interactive photo booth platform that could do real-time green screen compositing, body tracking via Kinect, and deploy branded experiences at events and permanent installations. Clients included ING Bank, Fox Sport, and Blijdorp Zoo — each requiring custom builds with tight deadlines.

Architecture Decision

Key decision: Invested in Kinect v2 depth sensing for gesture-based interaction (swipe, take photo, approve/reject) and green screen keying without traditional chroma key — enabling setups without physical green screens. Chose CEF Sharp for WebGL rendering, allowing rich 3D effects within the C# application framework. Built auto-update system so deployed boxes could receive software updates remotely.

Delivered 6+ major projects including ING Bank (2 versions), Fox Sport, Yumble (€33k contract), Blijdorp Zoo POS system. Two generations of BlndrBox shipped. Multiple permanent installations and event deployments. Platform ran from 2013 to 2017.
C#Kinect v2WebGLOpenGLCEF SharpPOS IntegrationSUB2R Camera
More Projects

A selection from 130+ delivered projects

Altavia creative production — IT architecture, ISO 27001, 8-service integration

Creative Production House

ISO 27001 • 8 service integrations (Google Workspace, Azure AD, CrowdStrike, JumpCloud, Snipe-IT) • WMS logistics API • 12+ years

 Rabobank digital magazine — PDF generation and distribution

Banking Digital Magazine

PDF generation • Postcode routing • Multi-edition publishing

 Kenosha manufacturing diagnostics website

Manufacturing & Diagnostics

Corporate website • Product catalog • Webshop

 Ideja multi-language security hardware webshop

Security Hardware E-Shop

WooCommerce • 9 languages • WPML • Multi-currency

 Pantarij chauffeur fleet management platform

Chauffeur Services Platform

Fleet planning • Driver management • Invoicing • Booking

 Flyerzone online print shop with PDF preflight

Online Print Shop

Print e-commerce • pdfToolbox • PDF preflight • Automation

 Drukland print e-commerce platform

Print E-Commerce

Online printing • Order management • PDF processing

 Beveiligd Nederland security systems platform

Security Systems Platform

Alarm systems • Helpdesk • E-commerce • Lead generation
In the Field

Physical infrastructure & field deployments

Diergaarde Blijdorp — Rotterdam Zoo

Technical infrastructure deployment at Rotterdam's iconic zoo. Systems designed for high-availability public environments with thousands of daily visitors.

New Park Development

End-to-end technology infrastructure for a new park development — from network architecture to visitor-facing systems.

Engineering in the AI Era

I use AI to build faster. Not to think less.

AI tools like Claude and ChatGPT are part of my daily workflow. But AI doesn't architect systems. It doesn't understand your business constraints. It doesn't know that the NetSuite API rate limit will break your integration if you don't design around it.

⚡

Acceleration, Not Replacement

AI helps me write boilerplate, generate test cases, and prototype faster. It does not make architecture decisions. The result is faster delivery without cutting corners on reliability.

🔍

Every Output Is Validated

I review AI-generated code the same way I'd review a junior developer's pull request — checking for edge cases, security vulnerabilities, and whether it actually fits the system architecture.

🧠

25 Years of Knowing What to Build

AI is a force multiplier for experienced engineers. I know what to build, what trade-offs to accept, and what will break at scale. AI helps me build it faster. That combination is what you're hiring.

What Clients Say

Trusted by companies across Europe

★★★★★
"Sinisa didn't just connect our systems — he architected the entire integration between NetSuite and PrestaShop, built our finance core from scratch, and manages 60+ servers and our Kubernetes clusters. Our order processing went from manual data entry to fully automated. He understands the business side, not just the technology."
Head of ITE-Commerce • 200+ employees • Netherlands
★★★★★
"We had an idea and a whiteboard. Sinisa turned it into a shipping product — he designed the BLE beacon hardware, wrote the firmware, built the iOS and Android apps, and deployed the backend. One engineer who owned the entire stack. Idea to market in under a year."
CEOIoT Startup • Netherlands
★★★★★
"We needed deep technical expertise in PDF processing and prepress automation. Sinisa built our pdfToolbox integration and production tracking systems, and they've been running reliably across 900+ installations worldwide for years. When we have a complex problem, he's the first call."
Operations DirectorPrint & Packaging • 900+ installations worldwide
Partners

Companies I partner with

IT-Mannetje — web design and IT consulting partner

IT-Mannetje

Web design • IT consulting • Infrastructure • Project management

 IBOcare — IT hardware and e-commerce partner

IBOcare

IT hardware • Workstations • Repairs • E-commerce

 ThinkStore — Apple specialist and e-commerce partner

ThinkStore

Apple specialist • IT hardware • E-commerce • Web design
Technology Stack

Technologies I use — grouped by what I use them for

Integration & ERP
NetSuiteSuiteScriptPeppolPrestaShop WooCommerceShopifyAdyenWordPress
Frontend & Mobile
ReactNext.jsReact NativeExpo TypeScriptVue.jsSwiftKotlin
Backend & APIs
Node.jsPythonFastAPI PHPJavaC# / .NET
Infrastructure & DevOps
DockerKubernetesGCPHelm LinuxNginxCaddyCI/CD PrometheusGrafanaGaleraCeph
Data & Storage
PostgreSQLMySQLRedisMongoDB SupabaseFirebaseNeo4j
IoT & Real-Time
BLENFCIoT WebRTCLiveKitFreeSWITCH
Print & Prepress
pdfToolboxPDF/APDF/X
How I Work

No surprises. No middlemen. No account managers.

01

We Talk

Free, no-obligation call. You explain the problem, I tell you if and how I can solve it — and whether I'm the right fit.

02

I Architect

Technical design, clear scope, fixed quote or hourly estimate. You see the plan before any code is written.

03

I Build

Weekly demos, direct communication via WhatsApp or call. You talk to the person writing the code, not a project manager.

04

I Support

Launch, monitoring, maintenance. Most clients stay for years because the systems keep working. 24/7 support available.

About

The value isn't the code. It's the decisions.

I'm Sinisa Devcic. In nearly three decades of shipping production systems, I've learned that most projects don't fail because of bad code — they fail because of bad architecture decisions made early, when the cost of fixing them was still low.

That's what I actually sell: the judgment to know which database to choose, how to structure an integration so it doesn't collapse at scale, when to build custom and when to use off-the-shelf, and how to migrate a running system without taking it down.

When you hire DynConnect, you work directly with me — the person who designs the architecture, writes the code, manages the servers, and picks up the phone at 2 AM when something breaks. I also lead teams, coordinate releases, and keep complex multi-stakeholder projects on track.

My rate is €125/hour. You're not paying for lines of code — you're paying for decisions that save you from six-figure mistakes.

FAQ

Common questions

What kind of projects do you take on?

Projects where systems need to connect, scale, or become reliable under pressure. Integrations between ERP and e-commerce platforms. IoT products that need to go from idea to market. Infrastructure that needs to handle real traffic without going down. If your business depends on software working correctly in production — that's where I operate.

How do you use AI in your work?

AI tools like Claude and ChatGPT are part of my daily workflow — they help me write boilerplate faster, generate test cases, and prototype quickly. But every output gets reviewed against the system architecture, tested for edge cases, and validated for security. AI accelerates my work; it doesn't replace the engineering judgment that comes from 25+ years of shipping production systems.

Do you work with existing systems or only new builds?

Both — but most of my work involves improving and connecting existing systems. Integrating NetSuite with your webshop, implementing Peppol e-invoicing, stabilizing a legacy platform, or migrating to cloud infrastructure. I also build new systems from scratch when there's no solid foundation to work with.

What kind of clients do you typically work with?

Companies that rely on their systems daily and need them to work without surprises. Growing businesses that have outgrown patchwork solutions. Teams that need senior-level technical leadership without the cost of a full-time hire. Typically 50 to 500+ employees across e-commerce, manufacturing, IoT, print, and financial services.

How fast can you start?

Usually within a week. For urgent issues — downtime, broken integrations, infrastructure emergencies — I can often step in the same day. Send a message and I'll confirm availability.

Fixed price or hourly?

Both. Fixed pricing for projects with clearly defined scope. €125/hour for ongoing work, advisory, or situations where flexibility is needed. Everything is discussed upfront — no hidden costs, no scope surprises.

Do you provide support after launch?

Yes — and most clients stay long-term. I handle monitoring, server management, updates, security patches, and emergency support. If something breaks at 2 AM, you can reach me directly.

Can you work with our existing team?

Yes. I regularly work alongside internal developers, external agencies, and cross-functional teams. I typically fill the gap between business requirements and technical execution — ensuring the architecture is sound and the implementation actually works in production.

What makes you different from an agency or dev shop?

When you hire an agency, you get a project manager, rotating junior developers, and overhead you're paying for. When you hire me, you get one senior engineer who owns the problem end-to-end — architecture, code, infrastructure, and production support. No handoffs, no communication layers, no learning on your budget.

How do we get started?

Send me a short message describing your situation or problem. I'll review it personally and respond within 24 hours with whether I'm a good fit and what the next step looks like. No sales pitch.

Let's Talk

Tell me what you need.
I'll tell you if I can help.

No sales pitch. No forms that disappear into the void. I personally read every message and reply within 24 hours.

Zeewolde, Flevoland — The Netherlands