Lucas BuchallaSesti

Senior Mobile Developer

Flutter • Swift • Kotlin • Architecture • TDD • Design Systems

Based in Valencia, Spain • Building performant mobile apps for 20,000+ users

Download CV
7+
Years Experience
20K+
Users Served
80%+
Test Coverage

About Me

👨‍💻

Performance-driven Senior Mobile Developer with 6+ years of experience in creating high-performing and scalable apps. Expertise in Flutter, Swift, Kotlin, and Angular with a focus on architecture, test-driven development, and design systems.

I specialize in building efficient, maintainable solutions that prioritize user experience and code quality. Passionate about mentoring junior developers and establishing best practices across teams.

Promoted from intern to Senior Developer within 5 years by virtue of persistent technical brilliance
Expert in Flutter, Swift, Kotlin, and Angular across mobile and web platforms
Design systems & component libraries architecture reducing development time by 40%
Test-driven development champion: expanded unit test coverage to 80%+
Mentor to 3+ junior engineers; led one from intern to mid-level engineer
Multi-platform scalable architectures supporting 20,000+ users with 97% crash-free sessions

Experience

Senior Mobile Developer

Lejour

02/2019 - Present
Full-time Remote (Brazil HQ) | Working from Spain
  • Progressively promoted from intern to Senior Developer in 5 years by virtue of persistent technical brilliance
  • Flutter adoption champion: reduced codebase by 25% and builds by 60%
  • Scaled mobile apps to 20,000+ customers with 97% crash-free sessions
  • Established design system and component library: reduced development time by 40%
  • Led TDD initiatives and expanded test coverage from 20% to 80%+
  • Mentored 3 junior engineers; led one from intern to mid-level engineer
  • Maintained consistent commit conventions with Commitizen across 7+ developer team
  • Built internal dashboards with Angular using best practices and latest versions
  • Collaborated closely with product and UX teams on user-centered features
FlutterDartFirebaseSwiftKotlinAngularTypeScript

Mobile Developer

Mude Health

02/2025 - 07/2025
Part-time Remote (Portugal HQ) | Working from Spain
  • Established and maintained multi-platform mobile features for wellness experiences
  • Led white-label app development with customization for multiple brands
  • Maintained shared codebase across different brand deployments
  • Organized cohesive Flutter library to ease UI elements and asset reusability
  • Achieved consistency and code reusability through effective modularity
FlutterDartMulti-platform ArchitectureComponent Library

Skills

Mobile

FlutterSwiftKotlinDartiOSAndroid

Frontend

ReactAngularJavaScriptHTMLCSSTypeScript

Backend

Node.jsNestJSAPI Integration & Testing

Database

PostgreSQLMySQLFirebase

Cloud & DevOps

AWSGitHubFirebase

Practices & Methodologies

TDDUnit TestingDesign SystemsAgileSoftware EngineeringState ManagementCode Optimizations

Projects

Lejour App

Wedding planning platform supporting 20,000+ customers with high-performance, scalable mobile experience.

Key Highlights:

  • 20,000+ customers with 97% crash-free sessions
  • Established design system reducing development time by 40%
  • Expanded test coverage from 20% to 80%+ with TDD
  • Modular architecture for scalability
  • Performance-optimized across iOS and Android
FlutterDartFirebaseSwiftKotlinDesign System

Mude Health

Multi-brand wellness application supporting rapid deployment across different health organizations while maintaining a shared codebase.

Key Highlights:

  • Led white-label development for multiple brands
  • Maintained shared codebase with brand customization
  • Organized cohesive Flutter library for reusable components
  • Achieved consistency through effective modularity
  • Scalable feature delivery across deployments
FlutterDartModular ArchitectureComponent LibraryAsset Management

Onboardly

Open-source Flutter package for building beautiful onboarding flows with spotlight effects and interactive tooltips. Zero external dependencies.

Key Highlights:

  • Published on pub.dev with 160 pub points and 197 weekly downloads
  • Spotlight effect for highlighting UI elements with customizable overlays
  • Interactive tooltips with flexible positioning
  • State management agnostic — works with any solution
  • Cross-platform: Android, iOS, Linux, macOS, Windows
FlutterDartpub.devOpen Sourcepub.dev

Languages & Certifications

Languages

PortugueseNative
EnglishFluent (C2)
SpanishIntermediate (B2)
ArabicBeginner (A1)
ChineseBeginner (A1)
GermanBeginner (A1)

Certifications

Basic 2 Arabic Certified

Centro da Língua Árabe

08/2023 - 11/2023

Chinese Certified

Fluency Academy

10/2021 - 08/2023

Get in Touch

I'm always interested in hearing about new projects and opportunities.

© 2026 Lucas Buchalla Sesti. All rights reserved.

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