iOS · Android · React Native
Julian Astrada
10+ years building scalable, user-centric, and maintainable mobile apps trusted by global companies and startups alike — from concept to launch.
Swift Kotlin TypeScript
10+ years shipping
15+ collaborations with clients & companies
50+ technical interviews led
5,000+ hours of freelancing
About me
Since I started my career in 2013, I have had the opportunity to work with a wide range of clients and teams, which has diversified the technologies, methodologies, and development patterns in my portfolio. I have worked both inside big companies and with clients on my own, rewriting code or building applications from scratch.
Nowadays, I work as a freelancer or contractor. I get clients on Upwork, where I achieved a 100% client satisfaction rate, or through referrals from previous happy clients.
I consider myself proactive, creative, and a fast learning person. I have the ambition to grow professionally, applying the engineering knowledge gained from the university. I am interested in mobile development, the use of the latest technologies, and supporting different devices.
Languages
- Swift
- Objective-C
- Kotlin
- Java
- TypeScript
- JavaScript
Platforms
- iOS
- watchOS
- Android
- Widgets
Practices
- Agile
- Leadership
- Mentoring
- Battery Optimization
- Multithreading
- Accessibility
- A/B Testing
Tools
- GitHub Actions
- Bitrise
- DataDog
- MixPanel
- Firebase
- AI
- Jira
- Notion
- Stripe
- GoogleMaps
- Lottie
- Statsig
Education
- Software Engineer Universidad Nacional del Centro de la Provincia de Buenos Aires (UNICEN)
- Systems Analyst Universidad Nacional del Centro de la Provincia de Buenos Aires (UNICEN)
Selected work
A few of the apps I've led or shipped — real products in Bluetooth tracking, career services and smart-home hardware.
What I do
End-to-end mobile — across native iOS, Android and React Native, from architecture and hands-on code to leading the team that ships it.
01.
Mobile development
Native iOS (Swift, SwiftUI) and Android (Kotlin), plus cross-platform React Native. One engineer across every major mobile stack.
02.
Team leadership & mentoring
Led mobile teams, hired and mentored engineers, and moved apps from outsourced to fully in-house.
03.
Architecture & scalability
Scalable architectures and modernizations across native and React Native — from legacy rewrites to shared cross-platform foundations.
04.
Ship & grow
From concept to store: releases on the App Store and Google Play, analytics, subscriptions, and the quality work that lifts ratings.
Frequently asked questions
A little more about how I work and what I bring to a team.
What platforms do you build for?
Native iOS (Swift, SwiftUI, UIKit), native Android (Kotlin, Java), and cross-platform React Native (TypeScript). I pick the stack that fits the product, team and budget.
Native or React Native — which should I choose?
It depends. Native shines for performance-critical, deeply platform-integrated apps; React Native is great for shipping one codebase to iOS and Android quickly. I help you weigh the trade-offs, and often combine both.
Do you prefer to manage teams or write code?
Both — I am a very hands-on leader. I set technical direction, mentor and grow engineers, and make the architectural calls, but I stay in the code every day. I genuinely enjoy writing code, and leading by example in the codebase keeps me close to both the product and the team.
What tools do you use to optimize development?
CI/CD is central: I run pipelines on Bitrise and GitHub Actions that trigger unit tests on every pull request, so regressions are caught before merge. I work in Agile/Scrum with short iterations, code reviews and clear definitions of done, and lean on automation — linting, formatting and reproducible builds — to keep the team fast and the codebase healthy.
How do you monitor the app after shipping?
Shipping is the start, not the finish. I wire up Crashlytics for crash and stability reporting, Datadog for logs, performance and alerting, and Mixpanel for product analytics. From there I watch metrics like crash-free rate, ANRs, cold-start time, retention, funnel conversion and feature adoption — turning real usage into the next round of fixes and improvements.
How do you use feature flags?
Feature flags let me ship safely and learn fast. I structure rollouts with layers and gates, and run treatment vs. control experiments to measure impact before a full release. Lately I have been using Statsig — for gradual rollouts, kill switches, and A/B tests that tie each feature change to real metrics.
What people say
A few words from people I've worked with.
I had the privilege to work with Julian. He is a pro developer, with great skills and fast execution. Julian is a team player, adjusts quickly and, more important, a great guy!
Rehired Julian on another project. As usual he delivered on time, and was very communicative throughout the project with consistent status updates. He also supported us with some issues after the project was done, proving to be a reliable contractor. A pleasure to work with.
We worked with Julian to develop a B2B iPhone and Apple Watch application. We were looking for a developer but also someone to guide us. Julian did both perfectly — a great developer who provided great suggestions.
Julian was good at looking for solutions, good at communication, good at having an "I will figure a way" mentality, and globally a pleasure to work with. I will work with Julian again.
Julian was a contractor on an iPhone & Apple Watch app. Not only is he a great software engineer, he is a dependable and communicative contractor, providing consistent updates and demos throughout the project.
Awesome experience! Julian is very communicative — he provided constant updates and showed demos of his progress, so we never had to worry about the status of the project. He was on time and gave us exactly what we wanted. Already have a second project for him.
We were inexperienced in the iOS world and came to Julian with unclear requirements, but he managed to be creative and came up with a lot of great suggestions. The project involved the Apple Watch and he was very knowledgeable on that part too. The app he developed is now released and available on the App Store. We look forward to keep working with him!