Senior Mobile Engineer | Flutter | Offline-first systems

Senith Umesha

I build mobile systems that stay fast, reliable, and useful in the real world.

With 3+ years of experience in Flutter and Android, I build production-grade apps and multi-platform systems across digital payments, POS, scheduling, analytics, and operational tooling.

Explore Projects Download CV

Production impact

These figures come from shipped systems I contributed to, including HowToPay Wallet, HowToPay POS, and SchedulerDesk.

Years building production mobile systems

10K+

HowToPay wallet users supported in production

100+

HowToPay POS clients supported

10+

SchedulerDesk active clients

LinkedIn GitHub

Professional Summary

Senior Mobile Engineer

Currently building cross-platform mobile systems at Interflext (PVT) Ltd with a focus on reliability, sync, performance, and real-world usability.

Location

Galle, Sri Lanka

Focus

Flutter, offline-first systems, fintech, POS, analytics apps, and scalable SaaS workflows.

Core Toolkit

FlutterRiverpodGetXMobXAndroid (Java / Kotlin)Clean ArchitectureOffline-first systemsSync engine designState management patternsFirebase

About

Engineering mobile systems that survive real-world complexity.

I am a senior mobile engineer who enjoys solving difficult operational problems, not just shipping screens. My work spans fintech, POS, offline-first SaaS tools, analytics apps, and the backend or admin systems needed to support them.

Over the last few years, I have built and scaled production mobile systems used by real customers, businesses, and internal teams. That includes digital wallets, order-management platforms, communication tools, and research-driven AI experiences.

The strongest part of my work is in the areas where mobile systems get hard: sync reliability, performance bottlenecks, complex state, operational workflows, and end-to-end ownership from mobile app to backend or admin tooling.

Offline-first architecturesPerformance optimization in complex appsBackend and admin systems that strengthen mobile appsAI integrations in mobile apps

Mobile Development

FlutterRiverpodGetXMobXAndroid (Java / Kotlin)

Architecture and Systems

Clean ArchitectureOffline-first systemsSync engine designState management patterns

Backend and Services

FirebaseFirebase Admin SDKNode.js / ExpressCloudflare WorkersREST APIs

Delivery and Tooling

CI/CDCrashlytics and AnalyticsPerformance optimizationDebugging complex systems

Offline-first systems

Designing sync engines, queued updates, local-first persistence, and conflict-safe flows that remain dependable under unstable connectivity.

Performance and stability

Profiling and fixing memory lag, long-loading screens, frozen UI states, and rendering or state inconsistencies in data-heavy mobile apps.

Mobile architecture leadership

Turning messy operational requirements into maintainable mobile architecture, stable releases, and engineering decisions that hold up in production.

End-to-end delivery

Shipping not only mobile apps, but also backend APIs, admin dashboards, payment flows, and the operational systems around them.

Experience & Education

Mobile engineering shaped by systems thinking, delivery pressure, and real operational use.

The through-line is consistent: build software that stays dependable under complexity, performs well at scale, and gets better with every release.

Work Experience

Career

Sep 2022 - Present

Mobile Application Developer

Interflext (PVT) Ltd, Sri Lanka

Core contributor on HowToPay POS, engineering offline and online sync flows, fixing scheduled-order queue race conditions, and implementing operational automation such as cash-shift auto-close at midnight.
Resolved deep performance issues across POS workflows, including memory lag, frozen screens, long loading indicators, and slow floor-plan or existing-order flows in high-data scenarios.
Contributed to Flutter delivery on HowToPay, a digital wallet serving 10K+ users, with secure payment flows, real-time transaction updates, and migration from a legacy Android codebase.
Built ScheduleDesk across 2 mobile apps and 3 web portals for service businesses, supporting appointment systems, role-aware flows, and real-time operations for 10+ active clients.
Shipped production work across ChatHTP and Julee while collaborating closely with backend, design, and business teams to deliver features under real production constraints.

Feb 2022 - Aug 2022

Intern Software Engineer

Shield Technologies (PVT) Ltd, Sri Lanka

Built a telemedicine mobile application connecting doctors and patients through scheduling and remote consultation flows.
Implemented authentication, notifications, and real-time synchronization with Firebase.
Integrated secure payment flows and improved code quality through refactoring and complexity reduction.
Strengthened hands-on experience in Flutter and Kotlin while shipping real user-facing features.

Education

Study

Sep 2023 - Aug 2024

BSc (Hons) Computer Science and Software Engineering

University of Bedfordshire, UK

Graduated with First Class Honors. Specialized in comparative integrated systems, research methodologies, emerging technologies, and project management. Final project: TaleCraft, a research-driven storytelling app focused on user engagement.

Jan 2021 - Feb 2022

Higher Diploma in Software Engineering

National Institute of Business Management, Sri Lanka

Graduated with a GPA of 3.5.

Oct 2019 - Dec 2020

Diploma in Software Engineering

National Institute of Business Management, Sri Lanka

Graduated with a GPA of 3.6.

Selected Work

A curated set of mobile systems across fintech, POS, SaaS, and analytics.

These case studies highlight the work I enjoy most: offline-first architecture, sync reliability, performance optimization, and shipping software people depend on every day.

9 curated case studies

ProfessionalProduction

100+ clients supported

HowToPay POS

Interflext (PVT) Ltd - 2025

A multi-platform POS platform for restaurants, retail stores, and business operations, built to support real daily store workflows across Android, Windows, and Apple devices.

FlutterSync workflowsPerformance profilingOperational automation

View Case Study Website

IndependentClosed Test

Stable closed test with 20+ releases

BetterTrade

Independent Build - 2026 - Present

A trade journal and analytics platform that turns raw trade logs into structured review loops, behavioral insights, and decision-grade reporting.

FlutterRiverpodFirebaseCloudflare Workers

View Case Study Website

IndependentClosed Test

Offline-first SaaS for small businesses

Orderly

Independent Build - 2026 - Present

An offline-first business management app for small businesses taking orders through WhatsApp and social channels, backed by sync, licensing, analytics, and admin tooling.

FlutterDrift / SQLiteFirebaseFirebase Admin SDK

View Case Study Website

ProfessionalProduction

10K+ users

HowToPay

Interflext (PVT) Ltd - 2023 - Present

A production digital wallet built for secure online payments, real-time transaction visibility, and cross-platform delivery.

FlutterFirebaseMobXREST APIs

View Case Study Google Play

ProfessionalProduction

10+ clients supported

SchedulerDesk

Interflext (PVT) Ltd - 2023

A scheduling platform for salon businesses spanning 2 mobile apps and 3 web portals, focused on bookings, coordination, and daily operations.

FlutterGetXFirebaseREST APIs

View Case Study Website

ProfessionalProduction

Messaging, voice, and media sharing

ChatHTP

Interflext (PVT) Ltd - 2025

A communication app focused on messaging, voice, media sharing, and staying connected through a simple mobile experience.

FlutterGetXFCMREST APIs

View Case Study Google Play

ProfessionalProduction

Wallet rebrand and relaunch

Julee

Interflext (PVT) Ltd - 2023

A wallet experience refreshed through rebranding, interface updates, and a cleaner production release.

FlutterMobXFirebaseREST APIs

View Case Study Google Play

Research

First Class Honors final-year project

TaleCraft

University of Bedfordshire - 2024

An interactive storytelling app that rethinks how users consume stories by combining AI, voice, and gesture-based interactions.

FlutterMediaPipeOpenAIFirebase

View Case Study GitHub

ProfessionalProduction

Restaurant ordering experience

DinersPOS

Interflext (PVT) Ltd - 2023

A dining and ordering system focused on menu browsing, order placement, and smoother restaurant interactions.

FlutterGetXFirebaseREST APIs

View Case Study

Contact

Open to senior mobile engineering work with teams that care about reliability, scale, and thoughtful execution.

Whether it is a fintech workflow, a POS system, or an offline-first SaaS app, I care about building mobile software that earns trust in real use and holds up under production pressure.

Email Me Download CV

umesha.pms@gmail.com

Phone

+94 71 199 7144

Base

Galle, Sri Lanka

Profiles

LinkedIn and GitHub