Jun 19, 2019

Poyan, Wolt’s Courier app developer: “What drew me in is the emphasis the company puts on tech”

Poyan blog

Did you know that Wolt’s tech stack is a lot broader than a single mobile app? We build all our tech in-house and wanted to write a bit more about what we do, and who actually does the developing here. In this blog series, we’re interviewing our engineers to give you a glimpse into the dev life at Wolt.

Today we’re featuring Poyan Nabati, who is an app developer for the courier side. The courier product development team strives towards the perfect experience for our hard working courier partners. The team is responsible for the app that our couriers use in their everyday work, but they also build multiple internal tools for courier lifecycle management. Wolt has over 10 000 courier partners.

What do you do here?

I am an app developer for the courier-side of things. We have three apps: courier, customer, restaurant. What I appreciate the most about the courier app, is that as a dev, you have really engaged users, and you quickly get feedback.

How long have you been at Wolt?

I’ve worked here for 6 months now.

Why did you choose to work here?

I think what drew me in was that there’s an emphasis on tech here. People have time to think about difficult things. Also I really liked all the people that I met. I was interviewing with companies in Germany as well, but I really enjoyed the relaxed and casual Nordic working culture and moved to Helsinki. Apart from the dark winter, it’s a great place.

“We have time to think about difficult things here. Also, I really like the people.”

What’s the most interesting technological challenge you’re currently working on?

The most interesting thing I’m doing right now is basically migrating our codebase that’s mostly been written in plain ol’ JavaScript to TypeScript, and using io-ts at the boundaries to ensure that all the data we are handling in the app is fully typed. We’re doing that to ensure that as we scale, and the size of projects and number of team members grows, we can keep up the quality and prevent unnecessary bugs to reaching our precious courier partners.  

What’s the most difficult technical problem you’ve encountered during your time at Wolt?

We once had a critical bug that was almost impossible to find. It appeared randomly and would hide tasks from some of the courier partners, and only sometimes. After a lot of head scratching, it turned out, one of the libraries we were using was silently swallowing an error that prevented the task to be shown, and the error itself was due to a flaw in the version of JavaScriptCore that was packaged with react-native. We ended up finding it after one of our team members diligently went through all of our dependencies and finally struck gold.

“One of the libraries was silently swallowing an error that prevented the task to be shown, and the error was due to a flaw in the version of JavaScriptCore.”

What technologies do you use?

React, react native, TypeScript, io-ts, redux, redux/redux-saga, styled-components, Storybook, CodePush

Favorite programming language and why?  

I’m biased because I’ve been working with JavaScript for so long, but for me, building quality stuff that people actually use has always been at the core of what excites me, and JavaScript generally lets you do that really quickly. Of course, I love statically typed languages as much as the next guy or girl, but I also do find some nerdy pleasure in the art of attentively manoeuvring through the JavaScript jungle with all of it’s quirks and kinks.

How can developers develop themselves at Wolt?

Generally, I think that the more senior you become, the less other people will be able to teach you directly and you have to reach out to that next level on your own. What I like about Wolt is that people generally don’t stress you to rush to a conclusion, and honestly, at this stage, I think learning for me is more about getting the time for doing deep work rather than getting “taught” by other people. With that said, I’m really appreciative of the fact that I have quite competent colleagues and just having them as mental sparring partners is a great way to challenge your thinking.

Want to join our team to build Wolt together? We’re hiring! Check out our open roles at 🚀

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