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SwiftLee 2019 in review: Top Swift Development blog posts

You know it’s been a great year if you have the feeling that it went really fast. After looking back on 2018 last year it’s now time to do the same for 2019 and look ahead at what 2020 will bring.

I’m amazed by the support throughout the year. I’ve met a lot of you at conferences, through Twitter or simply by email and I can’t wait to see what next year will bring. But first, let’s look back at 2019.

2019: The stats

Every day and every month I’m checking in with my stats. However, I’m not often checking my yearly stats and I’m always surprised to see the growth of one year:

20182019% Growth
Twitter Followers11006100+554%
Newsletter Subscribers0973+973%
Website Users41K371K+905%
Website Sessions49K462K+943%

Altogether, it’s great to see that hard work pays off but most of all, it’s great to be able to reach more of you to teach you something new

These are crazy results which I’m so happy with! 2019 has been the first year in which I wrote a blog post every week as I started writing weekly in May 2018. I’ve also doubled down on social media and I started my newsletter in January this year. Altogether, it’s great to see that hard work pays off but most of all, it’s great to be able to reach more of you to teach you something new!

A weekly newsletter

My year started with getting up to speed with Mailchimp for delivering a weekly newsletter. Slowly but shortly I’ve started gaining more and more subscribers with reaching almost the 1K by the end of this year. The newsletter improved over the months and even got nominated in the Swift Community Awards this year!


2019 has also been the year of podcasts for me. I did my first podcast recording together with John Sundell in which we looked forward to WWDC 2019. After that, several recordings followed with the Dutch company iCulture, Contravariance, SwiftCraft and Swift by Sundell.

I’m not yet at a point at which I will start my own podcast but it definitely got my interest. Let’s see what 2020 will bring!


Although I ended 2018 with quite a few talks on conferences I did not plan to do a lot of that in 2019. Looking back, I’m still happy to have attended and spoken at quite a few great conferences and meetups.

I did two talks at the Dutch CocoaHeads but decided to go for a workshop throughout the rest of the year. Swift Island invited me over to do a workshop on a WWDC 2019 topic which turned out to be Combine. I was very happy to give the same workshop at FrenchKit and Mobiconf later.

Open-source projects

Open-source projects were once again a big focus in 2019. Both personal projects and projects at WeTransfer are available as an open-source project.

It’s great to see projects like the App Store Connect SDK getting more and more attention. Our newest project WeTransfer Diagnostics is getting a lot of attention and is already released in a few apps. The greatest thing of this all is to see contributors helping our products improve. This is one of the biggest reasons for us to keep on open-sourcing our framework whenever we can.


In August this year, I decided to turn SwiftLee into an official company. This allowed me to reach out for sponsors and take the next step in growing forward. Bitrise reached out and decided to sponsor me directly for 3 months (!!). I’m still amazed by their support which helps me to grow even further.

Other community initiatives

Besides common things like Twitter and Podcasts, I’ve also been part of several community initiatives.

It started with an interview by Paul Hudson on iOS and Swift Job Interviews. Paul is added a ton of value to the community with all his work. He did another personal interview with me later in 2019 and also invited me to work as part of 20 authors on a book for charity. This project was called Swift for Good and resulted in a book that you can still order.

Newsletters are also very important for a blog to reach out to new users. Several newsletters covered my posts throughout the year in which iOS Goodies, iOS Dev Weekly, and Swift Developments stood out in the stats.

The most popular SwiftLee blog posts of 2019

Of course, we can’t look back at 2019 without listing the most popular blog posts of 2019. With a lot more visitors this year it’s been a lot more interesting to look at the most popular posts. Although you might have an idea already with the weekly popular posts tweet I’m sending out, it’s still quite a surprise.

1. Getting started with the Combine framework in Swift

WWDC 2019 brought a lot of new features and frameworks. Combine was definitely one of the bigger announcements and it’s not a surprise that this turned out to be the most popular SwiftLee blog post. Together with my Combine Playground it’s been a great resource for the ones starting with Combine.

2. Alamofire vs URLSession: a comparison for networking in Swift

It’s one of those often asked questions: should I use URLSession or should I go with the popular Alamofire framework? With Alamofire 5 coming soon this post will likely get more attraction in the near future. Either way, what is your opinion?

3. Weak self and unowned self explained in Swift

Swift makes a lot of things easier and nicer but there’s definitely a few things that keep coming back as hard to understand. For me personally this has been the concept of using weak or unowned self in Swift code. It turns out that I’m not the only one!

4. How to use for loop, for each, while, and repeat in Swift (in-depth)

My blog posts cover advanced topics as well as basics. One of those is my blog post on loops in Swift. As a more experienced Swift developer, you might find this one not so interesting but if you are just getting started, this is definitely a great resource covering loop in Swift.

5. Dark Mode: Adding support to your app in Swift

It’s quite impressive to see this post reaching the top 5 as it’s only been published on the 5th of November. Dark Mode support can be added since iOS 13 and has been announced at WWDC 2019. Of course, you need a blog post with detailed information for this!

Looking forward to 2020

After looking back at such a year it’s time to look ahead and see what 2020 will bring. It’s hard to predict the exact outcome but it’s easy to at least list what I think is going to happen.

I want to start with my hobby project RocketSim. Although I had hoped to release it this year, it did not happen. I’m planning to pick this up early next year to have at least a first version released.

Apart from Swift related projects, I’ll be busy building my own house. The planning is to finish it around July 2020 but with such projects, it’s really hard to say if that is realistic or not. Either way, it will definitely take time and stops me from doing a lot of on-the-side things.

I’ll definitely continue writing a blog post every week but I might not do a lot of other things. I’m going to explore what I can do with podcasting and I want to do at least 2 or 3 conference talks. This is already quite optimistic with the house being built but I’m sure I’ll do my best. The first meetup talk is already planned for Swift Paris on the 30th of January and I’ve also got my first conference talk scheduled for AppDevCon 2020.

There’s a lot more to come but I’d like to keep that for myself. Surprises are also fun, right? 😉

I’d like to end this post with a big thank you towards all my visitors, subscribers, and Twitter followers. 2019 has been a great year and I can’t wait to see what I’ll write in next year’s looking back blog post.



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