Ronan O Ciosoig

Expert in iOS architectures and application development. iOS initiatives include encryption in Core Data, animations with physics, voice recognition for language learning, video calling, eLearning, ePub processing, designing and building frameworks and libraries, and complete API designs.

• Programming: Swift, Objective-C, Kotlin, VueJS, Java, C, Perl, Ruby, Go, GraphQL
• Frameworks: Combine, SwiftUI, Core Data
• Collaboration tools: JIRA, Asana, Trello, Slack
• Languages: Bilingual English/Gaelic. Fluent Spanish, working knowledge of French and German.

Experience

iOS Architect — eDreams, Barcelona

July 2022 – present

Defined and own the architectural vision for the iOS domain, and built the tooling that let developers switch to a micro-apps model.

• Drove the evolution of the iOS technical stack. 12 teams switched to the micro-apps approach, cutting feature development time, speeding up testing, reducing technical debt and modernising the platform.
• Replaced Objective-C code with Swift.
• Restructured the network stack for modern concurrency.
• Cut build time by 90% by introducing binary caching, locally and on CI.
• Refactored GraphQL requests so they are fully encapsulated within feature modules.
• Cut automated testing time by 70% with selective testing: CI runs tests for changed code only, bringing CI time under 10 minutes.
• Collaborate with architects on cross-domain initiatives so engineering roadmaps align with business goals.
• Chief coach and evangelist to senior developers; lead training sessions on advanced Swift.
• Developed promotion criteria for senior developer roles; conduct technical reviews and assessments of promotion candidates.
• Regularly host and present technical talks, inside eDreams and externally (a monthly meetup for developers and architects across Barcelona).

Engineering Manager / Team Lead — eDreams, Barcelona

September 2021 – July 2022

Led a cross-functional team of 7 developers: iOS, Android and Java backend.

• Extended the eDreams mobile app with features for baggage, seats and pricing structures.
• Redefined the structure of the iOS project, which the development teams then implemented.
• Worked closely with development teams, designers and product managers on cross-platform delivery, removing bottlenecks and pulling in timelines.
• Supervised code reviews to make sure test coverage didn’t miss corner cases.
• Replaced an error-prone manual system for modules with an automated one that generates code built directly into the apps, significantly reducing time to market for new features.
• Updated the interview process with a guide of suggested, graded answers for a standard question set.

Lead iOS Developer — Wefox GmbH, Barcelona

May 2019 – September 2021

An app for users in Germany, Austria and Switzerland to buy home, car and liability insurance, review contracts and make claims.

• Led a team of 5 developers on feature refinement and design for the iOS app.
• Took a buggy, poorly received product to bug-free with high user satisfaction in 2 months.
• Extended an existing Clean Swift app with new features.
• Developed and rolled out a new version with a 100% SwiftUI user interface, Combine for logic and networking, and GitHub Actions for CI.
• Adopted a micro-modular approach on MVVM, with Tuist to support modularity and optimise build times.
• Enforced alignment across platforms on naming, code reviews and automated testing.

Developer / Engineering Manager — Stanwood GmbH, Berlin

April 2017 – October 2018

A fully remote mobile development agency.

• Defined a common core architecture for all mobile apps across the iOS and Android teams.
• Led development of open-source frameworks used across all platforms.
• Held regular reviews with the CEO on project outcomes, team performance and design recommendations.
• Joined weekly sprint planning and retrospectives for more than 30 running projects, guiding design and delivery.
• Owned continuous integration, deployment and delivery for the mobile apps.
• Managed code reviews and debugged live apps with large consumer bases.
• Ran weekly internal master classes, streamed live on YouTube.
• Turned around problem projects, lifting them above 4.5 stars in user ratings.
• Researched code-quality tools and drove their adoption across the company.
• Worked with the web team, coding in VueJS.

Developer / Tech Lead — Shootr S.L., Barcelona

May 2016 – March 2017

A startup building a consumer chat app for the TV market.

• Managed a cross-platform team of 7 developers, standardising processes and methodologies.
• Worked directly with the managing director on product vision and feature planning.
• Advised on a highly scalable architecture for future growth.
• Introduced Swift to the iOS team, Slack for collaboration, test automation and Agile practices.
• Ran deep-dive code reviews with external advisors to plan future improvements.
• Refactored the code base for scalability and flexibility.

Mobile Development Consultant — Sonomos Software S.L., Barcelona

July 2009 – May 2016

Mobile design and development, plus product management: requirements analysis, journey mapping, feature integration planning, roadmaps and technical specifications for clients across Europe and the US. Delivered more than 25 mobile and web apps, on projects from 2 months to 2.5 years, some of them white-label with multiple rebranded versions. Clients were in Barcelona, Berlin, Dublin, London, San Francisco, New York and Boston.

• Stanwood GmbH, Berlin (2015–2016): built a #1 App Store consumer app for Condé Nast (Glamour), with dynamic content, custom transitions and a feed that adapts to usage.
• Mobile Jazz & City of Barcelona (2014–2015): system architect and lead iOS developer for Vincles BCN, a social network for older people to help prevent loneliness. The proposal won the grand prize in the Bloomberg Mayors Challenge. Wrote the iOS and Android technical specification, including the database and API design.

Teaching

• Barcelona Activa (2010–2013): wrote and taught a monthly mobile-app course for company directors, three years running.
• La Salle University, Barcelona (2010): wrote the curriculum for and taught a 50-hour iOS development course for graduate students.

Education

• Universitat Politècnica de Catalunya — Postgraduate in Mobile Application Development
• University College Dublin — B.Eng. in Electronics
• ARM Holdings — ARM Technical Training
• Synopsys — Chip Synthesis

Certifications

• European Scrum Master Certified
• Professional Scrum Master I (PSM I), scrum.org