A guide to hiring a HealthKit developer
HealthKit is Apple’s framework for health and fitness data. It lets an app read and save things like steps, workouts and sleep in the Apple Health app, as long as the person agrees. Fitness, wellness, coaching and care apps use it to show people their progress without asking them to type in numbers. This guide explains what a HealthKit developer does, how to check a candidate and how to plan the work. It is for founders and product leads who want Apple Health in their iPhone or Apple Watch app.
What HealthKit does
Think of Apple Health as a shared notebook on the phone. Many apps and devices write to it, and with permission other apps can read from it. HealthKit is how your app joins in. It has many data types, from step counts to workouts and sleep. The app asks for each type it wants, and the person decides yes or no. The app never gets data the person did not allow.
Where a HealthKit developer fits
Our iOS developers build whole iPhone apps in Swift and SwiftUI, and many have touched HealthKit. A HealthKit developer is the person you want when Apple Health is central to the product, for example a workout tracker or a sleep app, or when it is the part that keeps breaking. For apps on several platforms, our mobile app developers can plan how the iPhone and Android parts fit together.
The jobs people hire for
The first job is reading data, such as showing a week of steps or a list of workouts. The second is writing data, such as saving a run or a meal from your app so it shows in Apple Health. The third is the Apple Watch, where workouts and readings start. The fourth is repair: numbers that look wrong, data that appears twice or an update that stopped working after an iOS release.
When a HealthKit developer makes sense
- You are building a fitness, wellness or coaching app for iPhone.
- You want your app to show data that people already have in Apple Health.
- Your Apple Watch app needs to share workouts with the phone.
- The health numbers in your app do not match what Apple Health shows.
- You need to sync chosen data to your own server.
If you only need basic step counts once, a general iOS developer may be enough. A specialist pays off when the data is a main part of the product.
Handle health data with care
Health data is personal. Ask only for the data types your app needs, explain the reason in plain words and let people say no without losing the whole app. Decide early what you store, where and for how long, and write it down so your whole team follows the same plan. Rules about this differ by country and by product, so check your own case with a qualified adviser. Please do not rely on a developer alone for that part.
Reading a HealthKit developer’s background
Ask for apps in the store that use Apple Health, and for a specific problem the person solved. Good answers talk about duplicates, units, time zones or permissions, because those are the real difficulties. Be careful with a background that lists the framework but gives no example of messy data.
Interview questions to try
- How do you handle the same steps reported by a phone and a watch?
- What does your app do when the person denies access to a data type?
- How do you keep data fresh when the app is closed?
- How do you test with realistic data before release?
- What would you store on our server, and what would you leave in Apple Health?
Listen for practical answers with examples. Doubt anyone who treats health data as simple numbers.
Try a paid mini project
Give each finalist a small task from your own app. Good examples are showing the last seven days of one data type with a permission screen, saving a simple workout, or finding why a total looks wrong. Pay for the time. Look at the care taken with edge cases and how clearly the person explains the work.
Plan the Apple side early
Apple asks apps to explain why they want health data, and it reviews apps before release. Allow time for questions from the review team and keep the Apple developer account and certificates in your company name. Remove access when the work ends.
Mistakes to avoid
- Asking for every data type just in case.
- Testing only on a simulator and never on a real phone with real history.
- Ignoring time zones when adding up daily totals.
- Storing more health data on your server than the feature needs.
Planning the whole app? See our iOS developers for iPhone work, or our mobile app developers for several platforms.