Tech Lead’s Checklist: What Makes a Kotlin Developer Stand Out in 2025

When it comes to Android development in 2025, Kotlin has taken center stage. Officially supported by Google, widely adopted by startups and enterprises, and favored by developers for its clean syntax and modern features—Kotlin is no longer the "new kid" on the block. For tech leads and engineering managers, hiring the right Kotlin developer has become mission-critical.

But in a market saturated with resumes and portfolios, how do you distinguish a standout Kotlin developer from someone who just knows the basics? How can you identify a Kotlin developer with the right mix of ability, experience, and attitude?

Let’s dive into the ultimate tech lead’s checklist—a blend of practical hiring insight and 2025 development trends—to help you build your next mobile success story.

1. Strong Command of Core Kotlin Features

A standout Kotlin developer should do more than write functional code. They must leverage Kotlin’s strengths to create performant, maintainable, and scalable apps. This includes deep familiarity with:

• Null safety: One of Kotlin’s hallmark features, eliminating the infamous NullPointerException.
• Extension functions: Writing cleaner, reusable code without touching existing classes.
• Coroutines: For running non-blocking operations that allow the UI to stay fast and uninterrupted.
• Sealed classes & data classes: For representing states, models, and sealed hierarchies efficiently.

Understanding and applying these features isn’t just good practice—it’s what separates competent developers from exceptional ones.

2. Experience with Android Jetpack Components

In 2025, modern Android architecture is inseparable from Jetpack libraries. A top Kotlin Android developer should be adept at:

• ViewModel and LiveData for lifecycle-aware data handling.
• Navigation Component for seamless and type-safe screen transitions.
• For handling local data persistence with an updated, developer-friendly layer on top of SQLite.
• WorkManager for handling background tasks under system constraints.

Mastery of Jetpack components ensures your Kotlin developer isn’t just writing apps, but building robust, future-proof systems.

3. Understanding of Clean Architecture and Design Patterns

Architecture has become non-negotiable in modern mobile development. Developers should understand and apply Clean Architecture, MVVM, or MVI patterns to create decoupled, testable codebases.

Why does this matter in 2025?

Because modern apps aren't simple—they handle API calls, state management, caching, push notifications, user sessions, and more. Clean separation of concerns allows for flexibility, ease of debugging, and team scalability.

4. Familiarity with DevOps and CI/CD Tools

In today's fast-moving tech teams, developers aren’t isolated from deployment pipelines. Your ideal Kotlin developer should have:

• Familiarity with GitHub Actions, Jenkins, or Bitrise for automated builds and testing.
• Understanding of version control branching strategies (e.g., Git Flow).
• Knowledge of mobile DevOps principles, like crash reporting, performance monitoring, and staged rollouts.

Mobile DevOps is no longer a bonus skill—it’s a necessity for faster release cycles and consistent user experience.

5. Cross-Platform Capability with Kotlin Multiplatform

Kotlin Multiplatform (KMP) represents one of the most significant advancements in Kotlin’s evolution. In 2025, many mobile-first companies are turning to KMP to reduce redundant code across Android, iOS, and web apps.

If you're building apps that span multiple platforms, you want someone who:

• Understands shared business logic via KMP.
• Has experience integrating KMP modules into native Android/iOS apps.
• Can troubleshoot serialization, platform-specific APIs, and dependency management.

Even if your current app is Android-only, hiring with Multiplatform in mind future-proofs your development team.

6. Proficiency in Testing and Debugging

Modern Kotlin developers must write unit tests, UI tests, and integration tests. Tools like JUnit, Espresso, and MockK should be part of their toolkit.

Testing isn’t just about coverage percentages—it’s about confidence in code changes. Look for developers who:

• Write testable code with clean separation.
• Use dependency injection frameworks (like Hilt or Koin).
• Can debug efficiently using Android Studio, log analyzers, and memory profilers.

Remember: scalable teams don't rely on just fixing bugs—they prevent them from happening.

7. Strong Communication and Code Review Skills

Even the most skilled Kotlin developer can slow a team down if they lack communication or collaboration abilities.

In 2025, remote and hybrid teams dominate the tech landscape. The best developers are those who:

• Explain technical decisions clearly in written and verbal forms.
• Engage in code reviews by providing thoughtful and actionable suggestions.
• Write clean, self-documenting code that others can understand easily.

These soft skills reduce friction, especially when scaling teams or onboarding new engineers.

8. Knowledge of Modern Tooling and APIs

Top Kotlin developers stay current. In addition to Android and Kotlin fundamentals, a standout candidate should be familiar with:

• Firebase (authentication, cloud functions, analytics)
• GraphQL and RESTful APIs integration
• Jetpack Compose for declarative UI development
• Gradle Kotlin DSL for optimized build scripts

The rapid pace of change in development demands flexibility in adopting new technologies.

9. Portfolio That Reflects Real-World Problem-Solving

Don’t just ask for GitHub links—ask what problems the developer solved, how they architected the solution, and how they handled challenges like performance, offline usage, or security.

You can read the solution in the code, but understanding the strategy gives you the complete perspective.

10. Understanding Industry Use Cases and Trends

A great Kotlin developer doesn’t work in a silo. They understand business context, especially in areas like:

• Fintech security and compliance
• Healthcare app privacy standards
• E-commerce performance optimization
• User retention and in-app analytics

Someone who can connect technical decisions to product outcomes adds immense value to your engineering team.

Final Thoughts

Whether you're scaling a startup or building an enterprise mobile app, your choice of developers makes or breaks product success. Kotlin’s capabilities go far beyond syntax—they enable cleaner codebases, safer runtime behavior, and more scalable mobile architectures.

If you're looking to hire Kotlin developer talent that truly stands out, it’s not enough to just filter resumes by years of experience. Look for developers who embody technical depth, architectural maturity, collaborative spirit, and curiosity about where Kotlin is heading.

The mobile development world is evolving fast. Make sure your team is too. Whether you're building your first app or refactoring legacy code, now is the time to hire Kotlin developer profiles that align with future-ready tech stacks, modern workflows, and long-term scalability.