Reddit’s mobile engineers share how they completely rebuilt the iOS and Android app, introducing a new core tech stack, modern architecture, and improved testing strategies at massive scale.
So now we have data points on how Reddit works, today - and how they went on a hiring spree for native mobile engineers since 2021, 10x'ing their iOS and Android team.
And we know a single dev built a good third-party Reddit app before, using an API that has since been retired, as the platform is moving to centralized client development instead of third party.
But have we not seen something similar before? Both on how APIs that encourage third-party client development can built impressive apps with tiny teams (see: Twitter 3rd party clients in the early 2010s) and also that platforms often shut APIs down as they commercialize (then: Twitter and X, now: Reddit)
This episode focused more on the engineering parts, and I was interested in this because Reddit is one of the very few companies left that has a large enough mobile team to warrant a mobile platform team.
I am not sure I want to go down the path of arguing that every company hiring more than one engineer building a product is doing it wrong... instead, wand to understand how different teams operate.
Also worth noting: what are things that a large dev team can do (and does do!) that a tiny team of 1 dev might not? What business logic does Reddit run on mobile that could not be done on backend, and why the massive investment in cost to move a lot more business logic onto the client side?
Behind every seamless tap, every instant load, there’s a quiet war of tradeoffs. Speed vs. stability. Innovation vs. infrastructure. The invisible labor of engineers who build the scaffolding of our digital lives and rarely get the mic.
What this post reveals isn’t just architecture—it’s ethos. A blueprint of choices made under pressure, guided by clarity, not ego. It’s not just how Reddit scaled. It’s how intention scales.
What patterns do we miss when we only celebrate the outcome?
and yet 99% of the third-party apps were better, and yet 99% of the third-party apps were made by a single developer. I am not trashing the reddit developers, this is to point that the company still is clueless what the community wants. It is Conway's law in living proof.
Wow, 200 mobile native engineers !
Apollo was way way better than the official reddit app while being developed by one person
So now we have data points on how Reddit works, today - and how they went on a hiring spree for native mobile engineers since 2021, 10x'ing their iOS and Android team.
And we know a single dev built a good third-party Reddit app before, using an API that has since been retired, as the platform is moving to centralized client development instead of third party.
But have we not seen something similar before? Both on how APIs that encourage third-party client development can built impressive apps with tiny teams (see: Twitter 3rd party clients in the early 2010s) and also that platforms often shut APIs down as they commercialize (then: Twitter and X, now: Reddit)
This episode focused more on the engineering parts, and I was interested in this because Reddit is one of the very few companies left that has a large enough mobile team to warrant a mobile platform team.
I am not sure I want to go down the path of arguing that every company hiring more than one engineer building a product is doing it wrong... instead, wand to understand how different teams operate.
Also worth noting: what are things that a large dev team can do (and does do!) that a tiny team of 1 dev might not? What business logic does Reddit run on mobile that could not be done on backend, and why the massive investment in cost to move a lot more business logic onto the client side?
"(30:55) The impact of migrating from Rust to GraphQL"
I believed there is a typo here, we are actually talking about REST and not Rust, right?
Same for the topic "Mentions during the episode" that references the Rust language webpage.
But overall, this was a really great episode!
Ahh AI is being used, that explains why the app keeps breaking
AI is actually not used, if you paid attention.
It’s easy to forget—
Behind every seamless tap, every instant load, there’s a quiet war of tradeoffs. Speed vs. stability. Innovation vs. infrastructure. The invisible labor of engineers who build the scaffolding of our digital lives and rarely get the mic.
What this post reveals isn’t just architecture—it’s ethos. A blueprint of choices made under pressure, guided by clarity, not ego. It’s not just how Reddit scaled. It’s how intention scales.
What patterns do we miss when we only celebrate the outcome?
Still becoming, with you ♾️
You dropped one of the only kind comments on this thread.
The others are just bitter for some reason.
Maybe they wanted to work @ Reddit, but we're never accepted or entertained
Learnt a thing or 2 here.
Didn't know Reddit had 200+ engineers working on a "simple" chat-forum app
and yet 99% of the third-party apps were better, and yet 99% of the third-party apps were made by a single developer. I am not trashing the reddit developers, this is to point that the company still is clueless what the community wants. It is Conway's law in living proof.
I hate to be disparaging but it’s 2025 and still markedly worse than Apollo was