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I’m Matías Seijas, a senior iOS software engineer who enjoys building reliable, user-focused mobile experiences—from core product workflows to cross-platform collaboration. I’ve led iOS initiatives ranging from invoicing and appointments to Mobile Check Deposit, partnering closely with engineering, product, design, and banking teams to ship stable, well-designed features across platforms. Earlier in my career I worked at The Browser Company building browser features on macOS and Windows with Swift and modern Apple frameworks. I’ve also played major leadership roles, including spearheading Flutter adoption at Betterment and mentoring engineers, helping teams move faster while improving developer productivity through shared mobile platform abstractions and a cohesive design system.…I’m Matías Seijas, a senior iOS software engineer who enjoys building reliable, user-focused mobile experiences—from core product workflows to cross-platform collaboration. I’ve led iOS initiatives ranging from invoicing and appointments to Mobile Check Deposit, partnering closely with engineering, product, design, and banking teams to ship stable, well-designed features across platforms. Earlier in my career I worked at The Browser Company building browser features on macOS and Windows with Swift and modern Apple frameworks. I’ve also played major leadership roles, including spearheading Flutter adoption at Betterment and mentoring engineers, helping teams move faster while improving developer productivity through shared mobile platform abstractions and a cohesive design system.

Matías Seijas

Software Engineer, Developer, Product Designer, +2

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I’m Matías Seijas, a senior iOS software engineer who enjoys building reliable, user-focused mobile experiences—from core product workflows to cross-platform collaboration. I’ve led iOS initiatives ranging from invoicing and appointments to Mobile Check Deposit, partnering closely with engineering, product, design, and banking teams to ship stable, well-designed features across platforms. Earlier in my career I worked at The Browser Company building browser features on macOS and Windows with Swift and modern Apple frameworks. I’ve also played major leadership roles, including spearheading Flutter adoption at Betterment and mentoring engineers, helping teams move faster while improving developer productivity through shared mobile platform abstractions and a cohesive design system.…I’m Matías Seijas, a senior iOS software engineer who enjoys building reliable, user-focused mobile experiences—from core product workflows to cross-platform collaboration. I’ve led iOS initiatives ranging from invoicing and appointments to Mobile Check Deposit, partnering closely with engineering, product, design, and banking teams to ship stable, well-designed features across platforms. Earlier in my career I worked at The Browser Company building browser features on macOS and Windows with Swift and modern Apple frameworks. I’ve also played major leadership roles, including spearheading Flutter adoption at Betterment and mentoring engineers, helping teams move faster while improving developer productivity through shared mobile platform abstractions and a cohesive design system.

Available to hire

I’m Matías Seijas, a senior iOS software engineer who enjoys building reliable, user-focused mobile experiences—from core product workflows to cross-platform collaboration. I’ve led iOS initiatives ranging from invoicing and appointments to Mobile Check Deposit, partnering closely with engineering, product, design, and banking teams to ship stable, well-designed features across platforms.

Earlier in my career I worked at The Browser Company building browser features on macOS and Windows with Swift and modern Apple frameworks. I’ve also played major leadership roles, including spearheading Flutter adoption at Betterment and mentoring engineers, helping teams move faster while improving developer productivity through shared mobile platform abstractions and a cohesive design system.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Work Experience

Senior iOS Engineer (Local Services team) at Square

May 20, 2024 - February 1, 2026

Senior iOS engineer focused on Invoices and Appointments apps. Built and maintained core invoicing workflows to ensure reliability and a high-quality seller experience. Owned the iOS implementation of Mobile Check Deposit in partnership with the Square Banking team. Partnered cross-functionally with Android, Server, Banking, Risk, Product, and Design to align on API design, shape user-facing features, coordinate phased rollouts, and ensure production stability across platforms.

Senior Software Engineer at The Browser Company

March 1, 2023 - March 1, 2024

Built key browser features across platforms on macOS and Windows using Swift. Leveraged AppKit, SwiftUI, The Composable Architecture, Swift Concurrency, and Combine. Collaborated with design teams to improve onboarding and core product interactions. Adapted quickly to changing priorities by shifting resources to meet evolving timelines.

Senior iOS Engineer (Mobile Payment Experience team) at Square

June 1, 2021 - March 1, 2023

iOS lead for the Mobile Payment Experience team. Built internal and third-party developer SDKs to interact with Square’s various product offerings. Devised the team’s roadmap, deliverables, technical blockers, and timelines to ensure successful execution and collaboration across teams. Mentored engineers and supported their growth through the development process.

Staff Engineer at Betterment

October 1, 2020 - June 1, 2021

Spearheaded company-wide adoption of Flutter, creating and delivering a 2-week training program for iOS and Android engineers. Embedded with mobile product squads to provide ongoing support during the transition. Helped create a Mobile Platform team responsible for frameworks, tools, and abstractions that increased engineer productivity. Established strong design-engineering collaboration practices to align decisions and deliver cohesive outcomes across teams.

Lead Mobile Engineer at Betterment

May 1, 2019 - October 1, 2020

Co-led mobile development efforts for the new Checking product launch. Mentored peers through code review, pair programming, and project sponsorship. Collaborated on designing and implementing a new mobile release and testing strategy.

Founder, Creator at Tailor

January 1, 2016 - June 1, 2018

Researched, designed, and built a smart closet ecosystem that learns from user interactions with clothing items. Used miniature low-energy sensors to collect real-time data and supported passive, human-centered interaction styles. Developed a heuristics-based clothing recommendation engine combining user sentiment and usage patterns with temperature and weather to generate outfit suggestions.

iOS Team Lead at Tanooki Labs

October 1, 2015 - May 1, 2019

Led iOS development and helped deliver prototypes and working applications from loose design requirements. Established development best practices and preferred architecture patterns. Piloted multi-platform mobile technologies using React Native and TypeScript. Worked with clients including WearWorks, obé Fitness, Hylonome, Quartz, Dow Jones, Market Touch, and Furenexo.

iOS Developer, UX Designer at Tech Kids Unlimited: LOLA

May 1, 2015 - November 1, 2018

Architected and built the LOLA iOS app, a digital tool to help children on the autism spectrum master social and daily living skills through funny, animated reminders. Designed and implemented the UI and app logic using Objective-C, iOS SDK, and Parse SDK. Handled frontend client work, data modeling, and backend API integration.