Shopify opened for business in 2006 and since then Resistor Software has worked on hundreds of Shopify stores and produced hundreds of Apps and customizations.

We understand that every business is unique. We've helped merchants book many more millions in sales that would otherwise have been difficult to achieve.

If you have a functional or logistical need for your store please do inquire about a fix using our expert talent. The solution is waiting for you.


Custom App Development

When you cannot find the perfect app to help you run your business with the shopify platform, Resistor Software can build it for you.

Apps that securely plug right into your store to provide the exact functionality and operations you need.

Custom fulfillments, custom shipping rates, custom shopping cart behaviours along with custom product builders or customizations.


The Value of Expertise

Resistor Software provides expert coding for shopify theme adjustments and highly reliable apps to greatly increase sales.

Whether you need custom javascript for your shop, some general advice on how to use shopify, or a complex app, we provide those services at a very reasonable cost to you.


Projects and Case Studies

Resistor Software Shopify Apps

App Spotlight

Resistor Software Apps Work as Hard as You Do


A sophisticated Cost of Goods Sold App supporting all Shopify sales channels

Managing cost prices is crucial to helping you monitor your shop profit and for knowing important values like how much your unsold inventory is worth at any given moment in time.

For speed and rapid processing of shop orders all cost prices for your inventory are stored in the Profiteer App itself. When you accept a subscription to the App all your sales history is downloaded to the App and all your inventory is setup in the App, with zero as a cost price for each variant.

Therefore the first task for any merchant installing the App is to set cost prices for all your variants. Once that is completed, you can rewrite the downloaded sales so that each variant with a zero recorded will have an actual cost price assigned instead. At that point, basic shop profit from sales is visible.

    • Track profit and margins for all sales
    • View Cost Price in Shopify Order Reports
    • Replace Free Sale items with accurate prices
    • Record sales with automatic currency conversion
    • Calculate COGS for any day of the year


We engaged Resistor Software to add real-time freight rates from our freight carrier ABF to our wholesale store. He created a private app to our specs that works great. He delivered the app ahead of time and under our budget. Dave is clearly a master of all things Shopify and the related technologies that make it so extendable. If you want it done right, you can count on Resistor Software.

– Standout Designs Reseller Store

We asked David from Resistor Software to solve a very complicated problem for us . We are based in Germany and shipping with UPS but, there are some islands in the North Sea where the shipping is much higher. David built a shipping app with a lot of logic and we are very happy with his work. Great and fast work, far beyond our expectations.

– Maître Philippe & Filles

Really incredible work on a custom app necessary for some business functions in my shop. I’ve never worked with somebody who is more knowledgable about Shopify and how Shopify works before. They took my vision and made it something real.

– Setup The Upset

Anyone looking for help with tricking out their Shopify store should definitely give Resistor Software a call. We simply couldn't do half the business we do without the tools he's built for us. 100% satisfied with his work and he's a great guy to boot!

– Fruit My Cube from Farmer's Market

I’ve contacted a few other “Experts” before, but Dave is what I call a “Real Expert”. I needed a square feet calculator for my store with minimum quantity etc..., Dave delivered in style - Go no further, Dave is your guy.

– pa2go

Dave Lazar at Resistor provided a simple solution to our need to collect personalized data from our customers. Every step of the way he guided us through the changes he had to make to the back end of Shopify and left us more knowledgable than when we began.



Posts & Tweets


Shipping Is Easy Right?

The Shopify forums and chat channels are chock-a-block full of merchants that subscribe to the theory that shipping is easy. Some common complaints include: Why can’t I have free shipping for a single product? Why can’t I ship free to a small list of local zip codes? What if I have one thing in a weird tube and everything else in a box?  MORE

Average Cost of Inventory

For accounting purposes there are a couple of ways of dealing with selling and purchasing of inventory and the changes in the cost of purchasing inventory over time. It is rare that a merchant will purchase items to sell in their Shopify store for the exact same price over time. It can be important to use an average cost price that takes into account these purchasing price changes over time. MORE

Shopify and Currency Exchange

The Profiteer App is meant to expose profit or margins on a sale by subtracting the cost price of goods sold from the selling price of the goods sold. A common business issue faced by many merchants is the effect currency exchange rates may have on their sales. A shop located in Canada may sell products to Canadians in Canadian currency, but the products sold may have been purchased and imported from the United States. MORE

A Word to the Wise

Had a real laugher/shocker at the same time. I develop so much App code where the data processing is a flow and not a stop:persist:process:continue action that sometimes you get burned by that. Everything was working fine as “hey download all that shop’s orders, parse them, deal with the contents, and move on”. Everything as working fine on MY itty, bitty, little dev shop. MORE