Bump
Bump is a fun, real-time location sharing app - built to let you see who’s around, what friends are up to, and meet up effortlessly. Created by amo (the same people behind Zenly), it’s packed with playful features like live ETAs, music sharing, and the ability to bump your phones to tell friends when you’re hanging out.
Get to know Bump
Who’s behind Bump?
Hi, I’m Antoine - I was the co-founder and CEO of Zenly, the original location-sharing app that was acquired by Snap and went on to become the biggest social app built in Europe with 50 million active users worldwide. I started building Zenly with my friend and co-founder Alex while we were still at college, and ended up working on it for a decade.
After Zenly got shut down by Snap, myself and some other members of the core team took a much-needed vacation before getting together again to build something new, and even more ambitious. The social apps we were using to keep in touch with friends were pushing us to watch content from strangers, all the while becoming more and more complex. These apps feel more like watching TV than a place to go to be with friends.
At amo, we’re building a suite of apps that bring you closer to your friends. With Bump, our location-sharing app, we didn’t even set out to create a Zenly replacement, but ended up being forced into it after all the copycat apps failed to fill the gap left by Zenly. It’s everything we wanted Zenly to be that it couldn’t, complete with all of today’s best tech.
What’s Bump and what’s so cool about it?
Bump is a social app that centers around a map instead of a feed or a camera, like we’ve gotten used to in other social apps. When you open the app, you’re immediately centered on the map at a zoom level that shows you at-a-glance where your friends are right now in relation to you. Everything in the app is reachable with your thumb and optimized for using on the go. Our intention isn’t to keep you doom scrolling for hours in our products - it’s to give you the info you need or the means to quickly check in with a friend, then to get off your phone and go spend time together IRL.
There have been multiple iterations on the feature set, the UX, the UI – we’re always evolving. But already, Bump has become a mature product, especially considering how short a time it’s been live and how small the team is. That’s really a result of the maturity of the team and the decade of experience myself and my co-founders have had thinking about a map as a canvas, day in and day out.
At amo, everyone who joins the team shares a deep respect for craft. The attention to detail is baked into everything we do. We push to build AAA mobile experiences – the kind of apps that feel rich, immersive, and smooth. That shows up in everything from the map interactions, how we organize information on the map, to the tiniest animations. The Android and iOS apps are built separately, so they can be fully optimized for each platform. We’re pushing the hardware to its limits, making sure everything runs beautifully without draining your battery – even while sharing location 24/7.
What makes it all work is that everyone on the team is aligned behind that vision. We’re all here because we want to build products used by the world that genuinely bring you closer to your friends, and make you feel good while using them.
Bump's Tool Stack
What’s under Bump’s hood? Which technologies were used and why did you chose them?
What really defines how we build Bump is how we work day to day. Our Android and iOS apps have separate code bases, so we can fully optimize for each platform. We ship to production three times a week. Our feedback loop is tight. We’re power users of Amplitude for analytics, and we’re constantly talking with users through DMs, App Store reviews, social media, and in-person user tests. That mix of speed, care, and listening lets us build something that feels effortless on the surface, but is the result of extreme attention to detail and thoughtfulness at every step of the development process.
Under the hood, everything at amo runs in a single monorepo, built with Bazel. That setup gives us fast, reproducible builds and makes it easy to share code across projects. On iOS, Bump is built in Swift using UIKit, with some components written in SwiftUI and Metal where needed. On Android, we use Jetpack Compose with Kotlin, and lean on a modular architecture to keep things scalable and fast.
One of the more unique parts of our setup is that core app infrastructure – networking, authentication, data sync, and more – is written in Rust and shared across both platforms. Thanks to our monorepo, this shared layer is just another module, and the interfaces to Swift and Kotlin are auto-generated. It hides all the complexity behind the scenes and lets us maintain consistency between platforms.
The backend is also built in Rust and runs on Google Cloud Platform, with Pulumi used for infrastructure. For storage, we rely on ScyllaDB, PostgreSQL, and Redpanda for data streaming.
For data and infrastructure, we use ScyllaDB for high-throughput performance - we’ve been using it for years and are still convinced by it, and PostgreSQL when strong consistency is needed, with Redpanda handling fast, Kafka-compatible data streaming. Our data platform is built to support both analytics and product features, using Protocol Buffers, Apache Beam, and BigQuery to process and query large volumes of structured data efficiently. We store everything in Parquet format on Google Cloud Storage for long-term access. CI and deployment are built on Bazel, GitHub Actions, and BuildBuddy – a setup that helps us move quickly, keep builds reproducible, and ship with confidence.
Everything in our stack is there to support one goal: delivering a mobile experience that feels light, fast, and personal – while handling a surprising amount of complexity in the background.
Do you use any other tools to run the business?
We use Slack for communication. Of course, everything on the design side runs through Figma – in fact, every single person who works at amo knows how to use Figma. So no matter what your role is in the team, you’ll feel comfortable articulating ideas or suggesting feature improvements with visuals, whether you’re a designer or not.
We’re also really big Arc users at amo. Josh, CEO of The Browser Company, the company that makes Arc, used to work out of our office here in Paris. So we’re a little biased – but honestly, even without the personal connection, we’d still use Arc because it’s just such a beautiful product that genuinely improves our productivity.
Shipping to production three times per week also means being open to getting things wrong and constantly monitoring the impact of our changes (both visible and invisible) on our userbase. On the quantitative side, we’re power users of Amplitude, actually one of their biggest users in the world.
On the qualitative side, we’re in constant conversation with our users. Everything from the disgruntled, to the confused, to the superfan who digs into every pixel – it’s all valuable. We take in feedback from wherever we can find people talking about the app.
In order to process and synthesize all of this feedback, we use a powerful combination of Intercom, Dust, Zapier, and Slack. On Intercom, we process all of our direct inbound from users, shared via our Care channels. We use Dust, a fantastic AI tool built by a super talented team here in Paris, combined with Zapier, in order to help synthesize the feedback from users and share it in Slack for the rest of our team to learn from on-the-go.
We use Linear as our roadmap and QA tool. And we’re big Notion users. That’s our internal doc system and knowledge base.
For our product videos, our motion designer uses After Effects and Cinema 4D. For videos across our Distribution channels, we are power users of Captions and are always first in line to try their new features that enable us to scale content creation with generative AI.
And when I asked the team if I forgot anything, someone said (fully seriously) Nespresso. Since we work in person, we go through a lot of coffee pods as a group.
What’s your personal stack? Which apps do you and your team love?
Arc is a big one for me - it’s part of my core productivity stack, along with Notion.
I use Workflow AI a lot — it helps with product development, but also with some of our internal processes. A few other tools I rely on: M1, which logs, transcribes, and sums up my calls so I can share them easily with the team. Superhuman is my go-to for email, and I use ProtoPie when I want to prototype an idea quickly.
Anything else you’d like to share?
Go download Bump — and get everyone in your favorite group chat on there. No more spamming everyone with “Are you on the way?”, “Where are you?”, “Are you with X right now?”
And if you download it and you like it — you should probably come work here. Check out our open jobs, especially if you want to work on products that are full of craft and delight, and that really push the boundaries of what’s possible in a mobile experience.
Now, discover Bump for yourself
Huge thanks to Antoine for sharing the story behind Bump and the details on the building blocks that make it such a special app. Now go try it out and enjoy it with your closest friends.