5 industrial challenges mobile applications can solve

How can mobile applications support industries to undertake a digital transformation? In supply chain, risk management, or information distribution, mobile applications will make tasks easier for your employees, thus increasing efficiency. Read about 5 industrial challenges that mobile apps can solve.

First of all, it is important to carefully chose between a web and a mobile application. Mobile apps are useful when they use one of the device’s native capabilities (e.g. Bluetooth, GPS, camera, etc.), and when they enhance the experience provided to the user (compared to what a web application could do).

Industrial challenges

The challenges industries face are often very good candidates for mobile apps as they leverage all their potential. Therefore, I have identified five recurring issues that industries are facing nowadays. These pain points can be easily relieved by mobile applications.

Challenge 1: Productivity issues due to technical limitations

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Going Crazy with Caching – HTTP Caching and Logged in Users

HTTP caching is an efficient way to make your application scalable and achieve great response times under heavy load. The basic assumption of HTTP caching is that, at least for some time, the same web request will lead to an identical response. As long as “same” means simply the same domain name and path, you will get many cache hits. When users are logged in, we have the opposite situation, where potentially everybody will see different content. Lets take a closer look to see where we can still find safe uses for HTTP caching even with logged in users.

Controlling the HTTP Cache Behaviour

A HTTP request is not only the URL, but also the headers. Some are only for statistics or not relevant for your application. But for some web applications, there are relevant headers. The Accept-Language header can be used to decide on the content language, or when building an API, the Accept header can be used to choose whether to encode the answer in JSON or XML.

HTTP responses can use the header Vary to declare what headers lead to distinct responses on the same URL. A HTTP cache uses the Vary to keep the variants of the same URL apart. This works well when there are few variants – you will still get frequent cache hits. However, if every request comes with a different header, caching on the server side makes no sense anymore. There is no benefit in storing results in the cache that will rarely be reused. Even worse, this is a waste of resources that should be used for caching relevant data.

For this reason, caching proxies like Varnish will by default not attempt any caching as soon as there is a Authorization or Cookie header present in the request. Cookies are commonly used to track a session in the application, meaning the user might see a personalized page that can not be shared with any other user. If you force caching with cookies and have your application send a Vary: Cookie header, you will have the situation described above, where you get no value out of your cache.

The rest of this article will dig into various aspects of what you can do to still do some HTTP caching:

  • Avoid Session Cookie, remove when no longer needed
  • Delegate to the frontend: “Cheating” with Javascript
  • Different cache rules for different parts
  • User Context: Cache by permission group

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Time for Coffee available on Android

Do you have time to take a coffee before your next public transportation connexion? Time for Coffee is a project initially started by François Terrier among friends in 2015.  We continued the work to make it available on further devices. 

When the Apple Watch came out, a few Liipers had the idea to make an app for it because having the next departures on the wrist was a perfect use case for this kind of device. The app received quite a lot of attentions in Swiss newspapers and received a Silver in the best of swiss apps in the category “Wearables & New Devices”. Since the Android world deserved also our attention, we made the app available for Android and Android Wear watches. The app is downloadable on the Play Store.

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The Data Stack – Download the most complete overview of the data centric landscape.

This blog post offers an overview and PDF download of the data stack, thus all tools that might be needed for data collection, processing, storage, analysis and finally integrated business intelligence solutions.

(Web)-Developers are used to stacks, most prominent among them probably the LAMP Stack or more current the MEAN stack. On the other hand, I have not heard too many data scientists talking about so much about data stacks – may it because we think, that in a lot of cases all you need is some python a CSV, pandas, and scikit-learn to do the job.

But when we sat down recently with our team, I realized that we indeed use a myriad of different tools, frameworks, and SaaS solutions. I thought it would be useful to organize them in a meaningful data stack. I have not only included the tools we are using, but I sat down and started researching. It turned out into an extensive list aka. the data stack PDF. This poster will:

  • provide an overview of solutions available in the 5 layers (Sources, Processing, Storage, Analysis, Visualization)
  • offer you a way to discover new tools and
  • offer orientation in a very densely populated area

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Hello, Rust! — An overview

This is my report of my talk at the TupperRust meetup hold in Lyon (France, February 2017) You find my slides available to download. 

The February 2nd 2017, I have presented a talk entitled Hello, Rust! — An overview about the Rust language. This language describes itself as safe, concurrent, and practical. The goal of this presentation was to give an overview of several features brought by the language, such as its strong safety guarantees, or speed and memory performances.

The slides are available online

First slide from the Hello, Rust! talk

This talk has been presented during the first TupperRust meetup event in Lyon (France). This is a serie of meetups focusing on Rust. The interaction was exceptional: The audience has been a great actor of this talk, and we even had a live-coding session on projects made by someones in the room. It was a great moment to talk about concrete problem, memory safety, performance etc.

It was also an opportunity to present a project that I have started here at Liip, called Tagua VM, which is an experimental PHP Virtual Machine that guarantees safety and quality by removing large classes of vulnerabilities thanks to the Rust language and the LLVM Compiler Infrastructure.

If you have any question, feel free to ask anything!

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Fresh inputs from Confoo Vancouver 2016

I was invited to present at Confoo in Vancouver, Canada. I gave my talk “HTTP caching with Varnish” and a Symfony introduction. After having been invited to Confoo Montreal early this year, it was great to see how Confoo got an even broader range of technologies and languages covered. Many talks where on concepts first, rather than specific languages: HTTP, in-application caching, databases and so on. Other talks actively invited to learn new languages, like “Python for non-Python developers”.

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Swift Alps Conference – experimentation and collaboration

The Swift Alps Conference has a special format focused on experimentation and collaboration. This is my report of the conference and the workshop Kilian and I held. The slides are available below.

Last month my colleague Kilian and I were pleased to attend the Swift Alps Conference, an experimental conference about Swift taking place in the Swiss Alps. This conference had a different format from what one can expect from a typical software development conference. In this case the format was more focused in experimenting and collaborating with other attendees with the goal of learning something new.

Experimenting with strangers

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Why bother with User Testing? Part 2 : Answer 5 common objections

User Testing is essential, just like I explained it in my last blog post. But your client / boss refuses to pay for this option. No, sorry, this is not an option. At all. They will argue that there is no money , that there is no time left, that the product is super simple, they already know the users…

1. Why bother with user testing? We perform well!

Client: no need for this, our product is great, we’re not leaders for nothing.


Designer: Oh really? If you never test it with users, how can you be sure that they don’t struggle regularly on your product?

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Accessibility: make your website barrier-free with a11ym!

Accessibility is not only about people with disabilities but also about making your website accessible to search engines robots. This blog post shares our experience with making the website of a famous luxury watchmaker more accessible, an important e-commerce application. We have built a custom tool, called The A11y Machine to help us crawl and test each URL against accessibility and HTML conformances. Less than 100 hours were required to fix a thousand of strict errors.

Issues with unaccessible application

Accessibility is not just a matter of helping people with disabilities. Of course, it is very important that an application can be used by everyone. But, have you ever considered that robots are visitors with numerous disabilities? What kind of robots you may ask, well: Search engine robots for instance, like Google, Bing, DuckDuckGo, Baidu… They are totally blind, they don’t have a mouse, they don’t have a keyboard, they must understand your content only with the source code.

Whilst it is easy to consider a man or a woman with a pushchair having a bad time in public transport, someone color-blind, a widespread disability, could also have issues browsing the web.

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User Testing Part 1/2 : Why you should perform them – The risks you avoid

If the team working on a project is competent, why should it be bothered with user testing? Because user testing does not mean that anyone is not competent enough. User testing is about avoiding risks and improving a product.

Great teams sometimes deliver wrong products

Yes, why?  We perform WELL, we are talented designers, Product owners, Product designers, we know our business, we are good enough so that we don’t design unusable stuff… Therefore, our clients can rely on us for delivering simple, intuitive and cutting the edge experiences through great products…

However, there are terrible websites online. There are terrible products on the shelves, there are garments that just don’t fit what they are supposed to, there are tools supposed to simplify our lives, but they are just bringing more complexity to our lives.

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