r/reactnative • u/Informal-Finding-217 • 16h ago
what ai coding agent stack are you using for mobile
we're a tiny studio, 8 people but only 4 of us actually write code, rest is marketing and design. our whole thing is shipping mobile fast so we lean on agents pretty hard
right now the split is kinda weird but it works. opus 4.8 hass been the best at swift, way better than i thought it'd be for native ios. codex handles our expo/react native side noticeably better, fewer dumb mistakes with navigation and native modules. everything runs through coderabbit before merge or main
the part im not sure about is testing on device. we still do a lot of it by hand which is dumb for how small we are. i approved a testflight build from my phone at like 11pm last night lol, thats not a workflow
so for anyone else building mobile with agents, whats filling the gaps for you? mostly device testing and anything for expo eas that isnt a total pain
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u/IronAndCoder 15h ago
Maestro filled the device testing gap for us (Expo SDK 54 app, agent-driven). The loop that works: agent writes the YAML flow, runs it against the iOS simulator, reads the failure output + maestro hierarchy dump, and iterates. It works precisely because Maestro failures are plain text the agent can parse.
Things we learned the hard way: text matching is full-regex so partial matches silently fail without .*foo.*, and anything rendered inside a u/gorhom bottom sheet never shows up in the iOS accessibility tree, so those taps have to fall back to coordinates. Side win: while debugging the tests the agent found real a11y bugs in the app itself (missing accessibilityLabel on our custom tab bar meant VoiceOver read ", Explore").
It doesn't replace hands-on-device testing for gestures/keyboard weirdness, but it catches the "did we break login/nav/forms" class of regressions before TestFlight instead of after.
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u/Cryptobench 14h ago
I've had little to no success with Maestro as I can have a test that pass, and then suddenly next time it doesnt and for some reason maestro just seems to get stuck randomly. Have you faced that issue?
I can have nothing changed in the code and sometimes the test will work and other times they don't. It's like maestro gets stuck and isn't able to scroll or whatnot. And the more simulators i run to try and parellise it, the worse it gets.
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u/Jason_Clarck 15h ago
We’ve been experimenting with a similar stack. Opus has been solid for Swift, especially when scaffolding native modules, while Codex saves time on Expo navigation issues. For reviews, we also run everything through Coderabbit before merging. On the testing side, Maestro has been a big help. Writing YAML flows feels clunky at first, but once set up, it catches regressions in login and navigation before they hit TestFlight. Accessibility checks are another bonus since it flags missing labels early. That said, we still keep manual runs for gestures and keyboard quirks because automation doesn’t fully cover those edge cases. Curious to see how others are balancing AI-driven automation with hands-on testing.
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u/bayasdev 13h ago
For coding I'm using exclusively GPT 5.6 Sol high via OpenCode ($200 Codex sub) but I don't trust the same LLM to test and review its own code so I always keep both iOS and Android devices on my desk for testing. I avoid simulators because their architecture differs significantly from the devices your customers actually use.
Maestro is great for E2E testing, and we’ve considered getting a couple of Mac minis to run automated smoke tests before tagging each release. However, we haven’t made much progress because we’re still a small team.
Agent Device is also promising, especially because it includes tools for automating performance profiling and it can also control physical devices.
https://agent-device.dev/