Custom software development
Web applications, APIs, back-office tools and automation built on .NET, designed around how your operation actually runs.
Learn moreSoftware & engineering services
Software that keeps warehouses, marketplaces and carriers talking to each other
We design, build and run the systems behind e-commerce fulfilment: custom software, integrations, a managed 3PL warehouse management system and security testing. Active today for clients in the United States, Canada, Japan and Türkiye.
Fixed monthly fees for managed services. Scoped quotes for projects. No long-term lock-in.
4Countries with active clients
2Offices: USA and Türkiye
40+Marketplace & carrier connectors
24/7System monitoring
What we do
Four services, one engineering team
Every engagement is run by the people who write the code. No hand-offs, no account layers, no surprises.
Integration & support services
Marketplace, carrier and e-commerce platform integrations, plus the monitoring and support that keeps them running.
Learn more3PL WMS provider
A warehouse management system for third-party logistics, delivered as a managed service with a fixed monthly fee.
Learn moreCybersecurity testing
Authorised penetration tests and vulnerability assessments for web applications, APIs and cloud setups, with clear remediation guidance.
Learn moreWhere we work
Active in four countries, delivered from two offices
GuneSys Corp was founded in 2023 in New Jersey. In 2026 we opened an engineering office in Ankara, Türkiye. Services are rendered remotely from Türkiye and the US to warehouses and online sellers that operate across borders, so time zones and languages are part of the job, not an obstacle.
United StatesHeadquarters in New Jersey; 3PL and e-commerce clients
CanadaWMS and integration services for fulfilment operations
Japan3PL WMS provisioning and marketplace integrations
TürkiyeEngineering office in Ankara; services for export-oriented businesses
3PL WMS as a service
A warehouse management system you don't have to run yourself
- Provisioning, configuration and maintenance of the 3PL WMS environment
- Warehouse operation parameters tuned to your workflows
- Marketplace integrations (Amazon, eBay, Walmart, Etsy, Shopify and more)
- Carrier integrations and shipping label purchase
- E-commerce platform integrations for your clients' stores
- System monitoring, maintenance and version updates
- Defect resolution and corrective development
- Technical support and user account management
How the service is billed
A fixed monthly service fee in USD covers the full scope above. New modules, new integrations, custom reports and data migrations are quoted separately before any work starts.
- Monthly invoice, 7-day payment terms
- Written scope for every add-on
- Cancel with 30 days' notice
How we work
From first call to a running system
A short, predictable path. Most WMS clients are live within weeks, not quarters.
Discovery call
We map your flows, volumes, channels and carriers, and tell you honestly what fits and what does not.
Written scope
You receive a scope, a timeline and a price in writing. Managed services come with a fixed monthly fee.
Build & configure
We set up the system, connect the integrations and test with your real orders and products.
Run & improve
Monitoring, updates and support are part of the service. Improvements are planned together, quarter by quarter.
Technologies and platforms we work with daily
.NET / C#ASP.NET CoreSQL ServerPostgreSQLDocker & LinuxREST, webhooks & EDIAmazon SP-APIeBay APIWalmart MarketplaceEtsyShopifyUPS · FedEx · USPS · DHLPlaywrightOWASP testing.NET / C#ASP.NET CoreSQL ServerPostgreSQLDocker & LinuxREST, webhooks & EDIAmazon SP-APIeBay APIWalmart MarketplaceEtsyShopifyUPS · FedEx · USPS · DHLPlaywrightOWASP testing
Why GuneSys
Small team, senior engineers, long-term relationships
Built by operators
Our team has run e-commerce and warehouse operations, so we know where orders get stuck and why stock goes wrong.
Clear commercial terms
Fixed monthly fees for managed services, scoped quotes for projects, invoices in USD, and nothing hidden in the fine print.
Two time zones covered
With engineers in the US and Türkiye we cover your working day in North America, Europe and Asia.
Blog
Latest from the blog
Choosing a WMS for your 3PL: seven questions to ask before you sign
Seven practical questions to ask a WMS vendor before your 3PL signs: integrations, billing, pricing, data ownership, support.
Have a project, an integration or a warehouse to run?
Tell us what you are building. We reply within one business day with a clear next step.