A step-by-step guide to scoping an iOS feature for Devin, letting it work autonomously, and turning its pull request into a shipped Swift change.
The goal of this guide is to get a real iOS feature written by Devin and merged into your Swift codebase. Devin will do the authoring; you will do the building, testing, and shipping.
Devin runs asynchronously in the cloud, so you delegate a task and review a pull request later. It is not attached to your Mac or your Xcode instance.
That means the final build, code signing, on-device verification, and any App Store submission are yours to perform in Xcode. Devin does not replace those steps.
Keep that division in mind throughout: Devin proposes code changes as a PR, and a human validates them on real Apple tooling before anything ships.
If you internalize only one thing from this guide, make it this split. Almost every frustration teams report with Devin traces back to expecting it to cross that authoring-to-shipping line that it structurally cannot cross.
Autonomous agents thrive on clear boundaries and struggle with vague, open-ended asks. Choose a feature you could describe to a competent junior engineer in a short paragraph.
Good candidates: adding a pull-to-refresh to a list, wiring a new REST endpoint into an existing networking layer, adding a caching layer, or implementing a settings screen backed by existing patterns.
Avoid, for a first task, sprawling work that depends heavily on visual polish or subjective UX judgment — those need constant on-device human evaluation that Devin can't perform.
Write down the acceptance criteria before you touch Devin. Knowing exactly what 'done' looks like will make both the prompt and the eventual review far easier.
A useful test: if you cannot state in one sentence how you will verify the feature is correct, the task is probably too vague or too large to hand off cleanly yet. Sharpen it until the verification is obvious.
Devin works against your source control, so it needs access to the repo. In practice that means granting Devin access to the GitHub repository holding your iOS project, following the setup steps in Devin's documentation.
Give Devin a repo that has a clean, buildable main branch and, ideally, existing tests. The more context and convention it can infer, the better its output.
If your project has a README, contribution guidelines, or a documented architecture, make sure they're present. Devin reads the repo to learn your patterns, so good documentation directly improves results.
Confirm branch protections and PR rules are in place. You want Devin's work to land as a branch and PR, never a direct push to a protected main.
Grant the least access that lets Devin do its job — the specific repository rather than your whole organization. That keeps the blast radius small while you are still learning how the agent behaves on your code.
Treat the prompt like a well-written ticket, not a wish. State the feature, the files or modules involved if you know them, the acceptance criteria, and any constraints.
For example: 'In the Feed module, add pull-to-refresh to FeedView. Call the existing FeedService.reload() method. Show the system refresh spinner. Add or update unit tests for the view model. Follow the existing MVVM pattern used in ProfileView.'
Spell out non-negotiables: coding style, no new third-party dependencies, keep public APIs stable, match existing naming. Devin honors constraints better when they're explicit.
If the task touches areas that can't be verified in a Linux sandbox (UIKit/SwiftUI rendering, device APIs), say so, and ask Devin to focus on logic and tests it can actually validate.
Include your minimum deployment target and any framework constraints in the prompt as well. Telling Devin up front that you support, say, an older iOS version prevents it from reaching for APIs that will not compile against your target.
Once you kick off the task, Devin plans and executes autonomously. Because it runs asynchronously, you don't need to babysit it — but you can and should watch the session.
Inspect its plan early. If Devin is heading toward the wrong files or misreading a requirement, that's the cheapest moment to correct course with a follow-up message.
Watch how it handles building and testing. For pure Swift logic and Swift Package targets, a lot can be exercised in its environment; UIKit/SwiftUI-heavy code may only be partially verifiable there.
Don't expect perfection on the first pass. Iterating with feedback — 'you missed the empty-state case,' 'add a test for the error path' — is a normal and effective part of the workflow.
The early plan review is the highest-leverage moment in the whole process. A ten-second correction to the plan can save you from reviewing a large, well-written diff that solves the wrong problem entirely.
When Devin opens its PR, review it exactly as you would a contribution from a new hire. Read every diff; do not merge on faith.
Check correctness, adherence to your acceptance criteria, style consistency, and whether any tests were added or weakened. Autonomous agents can produce plausible code that's subtly wrong.
Pay special attention to anything Devin couldn't verify itself — SwiftUI view code, device-specific behavior, concurrency, and edge cases. Those are where you'll find the most issues.
If something's off, request changes in the PR or send Devin another instruction. Keep iterating until the diff genuinely meets your bar.
Watch specifically for scope creep, where Devin touches files beyond what the task required. Unexpected edits to unrelated modules, build configuration, or signing settings deserve extra scrutiny and are often worth reverting outright.
This is the step Devin cannot do for you. Pull the branch onto your Mac, open the project in Xcode, and build it.
Run the app in the simulator and, critically, on a real device. On-device testing catches signing issues, performance problems, and UI behavior that no cloud agent can observe.
If the feature is ready for release, follow Apple's normal path: archive in Xcode, sign with your provisioning profile, and upload to App Store Connect for TestFlight or review. This requires an Apple Developer Program membership.
Only after this human-driven verification should the feature be considered shipped. Devin got you a reviewed PR faster; you still own the last, Apple-specific mile.
Expect that a clean build in Devin's Linux sandbox does not guarantee a clean build in Xcode. Treat the Xcode build as the authoritative verdict, and be ready to either fix small issues yourself or hand the exact compiler errors back to Devin.
Keep tasks small and independent. Several tightly scoped tickets beat one giant vague one, and they let you exploit Devin's asynchronous parallelism.
Invest in your repo's testability. The more Devin can run and verify in its own environment, the fewer surprises surface later in Xcode.
Maintain a written record of your conventions — architecture notes, style rules, dependency policy. Devin reads these, and they measurably improve output quality.
Finally, never let velocity erode review discipline. The whole model depends on humans vetting every PR and doing the real Apple-side build and submission. That's the guardrail that makes delegating to Devin safe.
Over time, feed the lessons from each review back into your prompts and docs. When Devin repeatedly makes the same wrong assumption, that is a signal your conventions were not discoverable in the repo, and fixing them once pays off on every future task.
It shouldn't. Devin's intended workflow is to open a pull request from a branch, which humans review and merge. Keep branch protection enabled on main so all of Devin's work lands as reviewable PRs rather than direct pushes.
Only partially. Devin can compile and test logic in its environment, but it cannot see a running app on an iPhone or judge visual and interaction quality. You must build and test UI changes on a device in Xcode before shipping.
Treat it like a well-written ticket: state the feature, relevant modules, acceptance criteria, style constraints, and any patterns to follow. The more precise the scope, the better and more reviewable Devin's pull request will be.
Merging is only the code step. To ship, you still open the project in Xcode, build, sign, test on device, and submit through App Store Connect with an Apple Developer Program membership. Devin does not perform any of those Apple-specific steps.