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Custom development

Our partners and clients consist of Fortune 500 companies, SMEs, the Dutch government, and non-profit organizations, leveraging us as an end-to-end production partner.

  • We build websites and web apps.
  • We build native, hybrid, and progressive apps.
  • We build software applications.
  • We build E-commerce stores and applications.
  • We simply blow your mind, and ehmm, we design.
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Flatline Agency Amsterdam HQ basement vibes

Supporting the migration of the data for one of the worlds largest companies in the world, together with one of the AWS lead architects.

Creating an AI dashboard in React for internal and operational use.

Their restaurants and loyal customers were connected by our hyper-personalised custom development

Building and designing a Python based dealer platform for all EU car dealers.

Consulting on a strategy to parallel real-life marketing in the virtual environment and elaborated on creating a virtual reality store

Why build it custom

Building custom means building it exactly the way you want. Making it lean, fast, UX or UI focussed, and therefore creating the perfect fit for your target group(s). Simply put, you just imagine and we build the perfect fit. Our ‘unique selling point’ is that we begin where every other agency stops.


We deliver high-quality work, fast – while leveraging the newest and best techniques available. All our products are breathtaking, responsive, and focused on the mobile-first generation – The perfect starting point for SMEs and the necessary creative push for the brands and larger corporations.

Mystic jeep cruising through the plains

Our Cases


As a production partner, we do not only help you with just building an application. We go beyond this minimal perspective and help you to set your future goals and create success as a service.

  • 01Web
  • 02App
  • 03Software
  • 04E-commerce


What development language and architecture should I choose?

It depends

There are many development languages out there, of which, a few are dominating the market: Python, PHP, NodeJS, React, React Native, and Flutter.

  • Python
  • PHP
  • NodeJS
  • React / React Native
  • Flutter

All of them have strong pros and cons and are created with different goals in mind. Choosing the ‘wrong’ language can result in delays, higher costs, impossibilities, a complete rebuild, or even have the project failing as a whole. Therefore, it is essential to not only think of the current state of your company but also elaborate on your future plans/vision. If an agency always sticks to ‘one favorite language’, it is highly likely they don’t operate in your best interest. Whenever the agency goes a bit deeper, elaborate on the characteristics, and let you ultimately decide – you can confidently say this will be the best.

Wait, the architecture

Besides simply choosing the ‘right’ language, it is also important to think about the architecture. The architecture states if it can scale, how stability will be assured, and many other relevant variables. Within every project, one should first draw out a proper architecture and be able to thoroughly elaborate on this. This is simply because this will be the core principle of potential success (or failure). Simply put, there are more roads to digital Rome.

Is custom development the right fit?

Want something unique?

While there are many low-code, no-code, and SAAS providers available, custom development is not always the perfect fit. This is because it may already exist and therefore is cheaper to use the available tooling. However, as soon as you want something that doesn’t exist 1-on-1 or really wants something unique, custom development becomes your next search on Google.

This not only gives you the freedom to style and design the digital product in an exact manner your target group would love to see it but also the possibility to create custom functions, making your product unique.

How would the process work and is it important?

Want something unique?

Not only is the built-in process important, but it is even essential for every development & design project. While the deliverables are ‘free of form’ – the process assures certain milestones, check-ups, and actually creates a necessary safety net for the client. For example, if dissatisfaction, miscommunication, or a mistake is detected early on, the impact will be minimal. However, at the end of a process, it can be horrific and very costly/time-consuming for both parties. Therefore, the process should always be able to match the size of the project and should be ‘agile’ (yes, I said Agile).

Therefore, only trust the agencies that are able to set up a strong yet flexible process. The high-level custom development & design process consists of (minimal) the following steps:

  1. Kick-off meeting
  2. Digital strategy session
  3. Empathy mapping
  4. Personas
  5. User stories set-up
  6. UX mock-up
  7. Design mock-up
  8. Technical documentation
  9. Development
  10. Testing and bug hunt
  11. Soft launch
  12. Public launch & Optimization.

Can I design it exactly how we like it?

Yes, you can!

We can be brief about this one. Yes, you can! Either deliver the design of your dreams or let us blow your mind and design the perfect application.

How are we able to scale?

Horizontal or vertical?

Scaling can be done in multiple ways and this can either be horizontally or vertically. When scaling vertically this for example means growing in the number of users. However, for example, sometimes a company decides to scale horizontally by scaling to 20 other languages and countries.

We build for semi-scale as the standard and know exactly how to scale from 2 to 120 million users. A few usefull examples are building a Headless application, a progressive web app, strong Devops, Headless CMS, the ‘right’ combination of development languages/frameworks, and much more.

Andy and Dylan sitting at the Future of Commerce event

Let’s grab a coffee?