How to avoid card programme woes: unlock innovation with a world-class developer experience

In addition to supporting partner ambitions, much of my work at Marqeta is driven by the expectations of today’s increasingly savvy consumers. They not only demand that their technology delivers a seamless payment experience but also want to see ongoing innovation from card providers. In my opinion, the only way to quench this thirst for better functionality is through open access APIs, which have the ability to truly democratise the payments sector. 

Thanks to APIs, startups are challenging established players. Leading the way with landscape-shifting new card concepts are chief technology officers and development teams. But all too often I see these innovators hit against obstacles when it comes to payment processing. This is because not all processors offer the same level of technological possibility. Sadly for many card programme owners, this isn’t obvious until it’s too late, with access to the developer sandbox only permitted after procurement. So how do we overcome this problem? 

Access to a sandbox before you buy will help you source the right tech partner

When I make an important purchase as a consumer I tend to evaluate and research the product beforehand. The more expensive the item, the more time spent considering options and understanding its functionality, quality, and after-sales support. Think of a laptop. It’s something you’re going to use for several years and it plays an essential role in your home and work life.

Most stores will display a range of laptops, allowing you to physically engage with them, with a spec written up on a placard next to the machine. Whilst useful this has its limitations. Contrast this with Apple’s approach. Their Genius Bar – a tech station located inside Apple’s retail stores, embodies the try before you buy ethos. They provide a concierge-style support with employees specifically trained and certified to work at the Genius Bar. They demo the products to customers – walking them through step by step and spending as much time as required with each individual. Their role is to ensure that customers get the most out of Apple products and to choose the right product suite, both hardware and software, that matches current and future needs.    

This is exactly the approach I think companies should take to procuring payment platforms. After all, before you part with any cash or make long term commitments it’s vital to know that your processing technology is going to be up to the job both now and in future years as your requirements change. 

The moral of the story is to always try before you buy. You don’t want to be in the position of discovering the limits of a prospective partner’s technology after you’ve signed a three to five year contract. Sandbox transparency is key. In my opinion, there shouldn’t be a compromise on a platform’s ability to meet your growth and innovation plans. For that very reason, Marqeta allows developers to access our instant-issue sandbox before any commercial agreement is put in place. 

Helping developers understand Marqeta’s possibilities  

At Marqeta we know how frustrating it can be to come up against limiting technology. It’s why we built our own processing platform. Having started out as launching our own card programmes we struggled to find a processor who was able to deliver against our vision, we realised it was the only option. We want to help others avoid our growing pains. 

Marqeta’s technology has been made available to payment innovators through an instant-issuance  private sandbox, accessible via a simple signup process that takes a matter of minutes. Once in, I’m confident any developer will agree that our API offering and supporting documentation are nothing short of world-class. We want developers to realise their potential and that’s why our focus is on providing a platform that allows users to quickly build, test, and launch card products on their terms. 

Marqeta’s APIs are consistently world-class

Whilst API might be on its way to becoming a household term, it’s essential to know that there are huge inconsistencies in quality. Poorly documented APIs can make for a challenging developer experience. Marqeta is an API-first company and we offer endpoints to build, test, launch, and iterate a card programme. Our API endpoints are consistent, intuitive, fully documented, reliable, have functional coverage, work in real time, and use modern technology. Let’s take a look at these qualities one by one.


Our APIs are thoughtfully designed and follow common standards. For example, we use primary API endpoints (e.g. /cards, /users, / card transitions) to denote the major objects on our platform. The child endpoints (e.g. /cards/{token}) use the same JSON model as the parent.


We want developers to quickly understand how to interact with our platform. We ensure consistency and common standards because we know that developers engage with dozens of APIs. This approach saves considerable time in building out a new card programme.


A common problem, poor documentation makes it difficult for developers to understand how to interact with the API and get it to do what they want. For this reason, we’ve built out a whole developer portal dedicated to API resources.

Functional coverage

What is the API capable of? If it’s an issuer-processor API that doesn’t allow you to create cards, that’s not so useful. The richer the functionality the better.


If APIs don’t perform, the entire proposition falls. Our API call response times of sub 1,000ms at a 99.99% threshold ensure an excellent customer experience in the rapid exchange of required information and data. With so much card functionality in real time, unreliable APIs seriously affect the customer experience. 

Real-time actions

Customers want their balance updated instantaneously and need to be able to block a lost or stolen card from being used without delay. Many of the legacy issuer-processors offer APIs that don’t work in real time, but rather queue them up for later. This presents challenges to the customer experience.

Modern technologies

We use modern JSON and REST, developer-friendly technologies, and provide SDKs in either Python or Ruby. It’s a world away from XML, which has been a popular for decades and remains common amongst older issuer-processors.

A good developer can blame their tools if they’re not up to scratch

If you’ve invested in top developer talent, then I think it makes sense to equip them with the right tools to do the job. Getting this combination right will give you the best possible chance of delivering a world-class card programme with the ability to challenge existing players and push boundaries. It’ll also ensure you have the agility to move with the market and stay ahead of competitors. No matter how good a developer, if the tools aren’t up to the job your vision will face serious obstacles.

The other critical point I’d like card programme owners to remember when engaging a processor is that it’s usually a multi-year commitment. Only choose a partner who’ll let you try the technology before you sign a contract. That’s what we allow at Marqeta because we want our customers to be sure that our offering is the right fit for their proposition. 

It certainly is for Swiss challenger bank YAPEAL, whose Co-founder/CPO Daniel Capraro had this to say about Marqeta: “It took only 4 hours to do a full implementation – defining our card product, issuing first cards through to first transaction – this all working within 4 hours.” 

The same goes for Twisto, the Czech-based buy now, pay later pioneer. Its Chief Growth Officer Renata Salata says this about working with us: “Marqeta has been a great fit for Twisto – we share a similar mindset around looking for solutions aimed at bringing challenger products to market as quickly as possible. We see our partnership strengthening over time as our mutual technical offerings expand to provide a better payment experience for customers throughout Europe.” 

If you like the sound of our approach, why not sign up to the sandbox? It takes just a few seconds and you’ll soon begin to realise the endless possibilities with the platform.