GDPR and Security in Mobile Development

A Few Things to Know Before You Start
Privacy compliance doesn’t spark joy, does it?
Nobody’s ever stood up in a sprint planning and said: «I can’t wait to work on data retention policies this week». But, speaking with metaphors – ignoring GDPR, CCPA, or basic security principles is the mobile equivalent of building a house and forgetting the locks.
There are many ways to complicate your product. One of the most risky? Forgetting that data privacy isn’t optional. It’s tempting to treat it as something you’ll «sort out later». After all, we are busy building core features, right?
But here’s this thing about privacy: it doesn’t wait politely in the backlog. It quietly spreads into everything and once your app goes live, it gets harder (and pricier) to fix.
Not All Privacy Laws Are Created Equal (But All Are Serious)
Let’s start with the legal landscape.
The EU’s GDPR is strict and comprehensive. It requires consent to be explicit, data to be minimised, and users to have full access to (and control over) their personal information. And yes, fines are enforced.
The California Consumer Privacy Act (CCPA) takes a different approach with its own distinct requirements. It focuses more on transparency and opt-outs, though there are important nuances in how it applies compared to GDPR. Its successor, CPRA, introduces additional protections, signaling the evolving nature of U.S. data law.
You can’t design a great app and then slap a privacy on top. Because it affects what app collects and stores, what happens when a user deletes their account. It is architecture-level stuff: permissions, databases, retention logic.
Collect Less
Just because it is easy to collect everything, it doesn’t mean the app should.
In the world of mobile apps, excessive data-collection is common: crash reports that grab personal info, third-party SDKs silently logging user behavior, permissions that overreach. But when GDPR enters the chat, «data minimisation» isn’t a suggestion – it’s the law.
If it has nothing to do with core functionality, don’t ask for it.
And if it does? Better explain why, using plain English 🙂
If the app asks for location, camera, contacts, and calendar access before the user even finishes registration – it looks a bit clingy, isn’t it? Excess data increases liability. And once it is stored, app owners are responsible for it. The rule is simple: the less user data app stores, the less business would have to protect.
CCPA is more forgiving here: users can opt out instead of opting in, but the direction is clear: transparency wins. Readable language, and a real «no thanks» option should be the default.
Consent flows are UX now, so we have to treat them like UX. No dark patterns. No legal walls of text that is extremely difficult to read and understand. Just informed, respectful choices.
Security as a Habit.
GDPR tells what to protect. Security is how you do it. And when you do it – do it well. If your app is storing personal data, even basic stuff like emails or names, encryption shouldn’t be an extra. And if a mobile app touches health info, financial records, or anything remotely sensitive, every decision matters. Where one stores, how data is encrypted, what the backend logs, what the app does in background mode. All of it.
And no, it’s not just about the code. It is also the SDKs you embed, the cloud services you trust. In mobile, that means:
- Encrypting sensitive data (on-device and in-transit);
- Storing Data according to the latest security standards;
- Avoiding overly permissive app behavior or insecure third-party SDKs.
Oh, and speaking of third parties!
A few words about IDFA – the identifier that powered mobile advertising for years. With iOS 14.5, Apple made tracking opt-in, and many users opted out. Suddenly, the entire mobile ecosystem had to reckon with changing user privacy expectations.
It wasn’t just a marketing issue. Developers were forced to rethink how apps work without constant tracking. Designers had to make privacy screens that people would actually read. Product teams had to ask: what happens when a user says «no»?
That question still matters. Whether it’s IDFA, cookies, or crash reporting, app developers should now assume users will opt out, and thus make sure the app accommodates that and still delivers the desired user experience.
It taught us this: when given a clear choice, many users will limit data sharing. So your product better be ready to function well, even when tracking is off and data is limited.
Why Should We Be Cautious With Every SDK
Your app might be squeaky clean. Your SDKs? Worth a careful look.
Mobile products depend on third-party libraries for analytics, payments, maps, ads. But every integration is a potential data handling concern, and it’s the app owner’s name on the app, right?
Just because a vendor says they’re GDPR-compliant doesn’t make it true. Review what they collect. Understand how data flows. Look for EU-hosted options. And if you are building for global users, consider local laws (like China’s CSL or Brazil’s LGPD) while you’re at it.
One of the easiest ways to break GDPR, or any other data protection law, is to integrate a third-party SDK without understanding its data practices.
Bonus risk: unreliable SDKs can get you kicked out of the App Store. Apple and Google are watching us all.
Implementing the Right to Erasure
The most overlooked part of compliance? The end of the data lifecycle.
Users have the right to be completely forgotten. That doesn’t just mean deleting a row from the user table. It means logs, backups, analytics, caches, and anywhere else their data might have wandered in.
If an app doesn’t have a clean way to erase a user and all their data, unfortunately, it’s not compliant enough. Design your data flows like you’ll have to remove them completely. Because eventually, you will. If you build it well, a single action can wipe everything gracefully. If you don’t, deletion becomes a manual, error-prone nightmare.
One last thing
There is no need to be a privacy lawyer.
There is no need to encrypt every pixel or predict every regulation that might exist five years from now. But some situations will benefit from legal expertise – especially for apps with complex data processing.
Security and privacy aren’t blockers. They are part of what makes your product stable, trusted, and built to last. They protect your users, your business, and your future self from unpleasant conversations with legal teams (or app store reviewers). And the good news? None of this has to be scary, if you think about it early.
We build with that in mind. Because we have seen and heard in the news what happens when teams treat privacy and security as someone else’s job.