Available to hire
I’m Demian Turner, a product-focused tech leader and entrepreneur who’s built and scaled engineering teams, launched profitable ventures, and delivered high-impact iOS/macOS apps used worldwide. I’ve grown mobile teams from scratch to 20+ developers, cut compile times by 65%, boosted test coverage to 80%, and consistently shipped polished Apple platform apps for global clients.
Alongside leading startups—bringing dozens of apps to market, including several App Store #1s—while running lean, profitable operations. I remain deeply hands-on as a senior iOS engineer, writing production Swift daily and architecting both front-end and back-end systems. Recently, I’ve been shipping AI-powered apps using models from OpenAI, Anthropic, Google DeepMind, Microsoft, and Perplexity AI.
Skills
Experience Level
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Beginner
Language
English
Fluent
Work Experience
Mobile Team Lead at Lloyds Banking Group
March 1, 2021 - October 10, 2025Scaled the mobile team from 1 to 20 engineers in 18 months, accelerating iOS delivery and technical maturity; delivered greenfield compliance-archived search app using Swift, TC A, and SP M; designed a modular architecture that improved coder readability by 80% and halved integration time; achieved 82% test coverage and automated CI/CD; partnered with stakeholders to shape product direction and roadmap.
iOS Architect at Lloyds Banking Group
March 1, 2021 - October 10, 2025Led iOS architecture decisions for large-scale banking apps, reducing build times and stabilizing banking data flows; implemented SMS2FA workflows and fixed session timeout issues; contributed to platform-wide iOS strategy and tooling.
Senior iOS Developer at Sun Life Financial
August 1, 2018 - October 10, 2025Full-time Montreal, Canada; oversaw a team of 25 iOS developers on a client app for a 5-user configuration; reduced crashes and compile time; introduced MVVM and coached team in independent dependency injection; contributed to platform stability and performance improvements.
Co-Founder / Mac Developer at Doris Productivity App
January 1, 2018 - October 10, 2025Co-founded a productivity app startup; built MacOS and iOS clients alongside a REST backend; grew user base and established initial product-market fit while maintaining lean operations.
Founder / CTO / Team Lead at Sea Gull Systems
January 1, 2017 - October 10, 2025Founded an iOS agency delivering 50+ apps to the App Store between 2008–2014; built award-winning apps for EDF Energy, HarperCollins, Dolce & Gabbana, Chanel; 4 apps reached #1 in their category; delivered 25 major projects over 6 years with consistent profitability.
Founder / PHP Developer at Sea Gull Framework
January 1, 2012 - October 10, 2025Freelancer remote; created an open-source PHP framework with 1M+ downloads and 2K active developers; maintained for 10 years with 4K commits and 25K mailing list messages.
CTO / Co-Founder at Kin Do Network
March 1, 2008 - October 10, 2025Co-founded and led technology efforts for a London-based startup; responsible for product direction and technical decisions during early-stage growth.
Freelancer / Remote at Various
January 1, 2014 - October 10, 2025Provided freelance development services including iOS/macOS client work and backend integrations; contributed to multiple projects across timelines.
Founder / PHP Developer at Sea Gull Framework
January 1, 2012 - October 10, 2025Freelance remote; created open-source PHP framework; 1M+ downloads, 2K active developers; 10-year maintenance with 4K commits and 25K mailing list messages.
Founder / CTO / Team Lead at Sea Gull Systems
January 1, 2014 - October 10, 2025Founded iOS agency delivering 50+ apps to App Store between 2008–2014; built award-winning apps for major brands; led multiple projects to #1 in category and sustained growth.
MyHeritage Senior Mac Dev / Tech Lead at MyHeritage
January 1, 2015 - October 10, 2025Led MacOS development across EU/Israel teams; delivered polished Mac apps for family tree and genealogy; integrated Obj-C, Obj-C++, and C++ layers with Sea Gull Framework Sea Gull Framework.
Mobile Team Lead at Global Relay
April 1, 2025 - October 10, 2025Scaled the mobile team from 1 to 20 engineers in 18 months, accelerating iOS delivery and technical maturity. Delivered a greenfield compliance architecture search app using Swift, TCA, and SPM. Designed a modular architecture that improved coder usability by 80% and halved integration time. Achieved 82% test coverage and automated CI/CD workflows with Jenkins. Partnered with stakeholders to shape product direction and refine road map priorities.
iOS Architect at Lloyds Banking Group
March 1, 2021 - October 10, 2025Reduced compile times from 23 minutes to 8 minutes. Implemented SMS 2FA flows and fixed session timeout issues. Maintained large-scale iOS banking codebase in Swift 5.
Senior iOS Developer at Sunlife Financial
August 1, 2018 - October 10, 2025Full-time Montreal, Canada. Oversaw team of 25 iOS developers on a 5 million user app. Reduced crashes and compile times from 15 minutes to 4 minutes. Introduced MVVM and coached team in dependency injection.
Co-Founder / Mac Developer at Doris Productivity
January 1, 2018 - October 10, 2025Part-time London, UK. Co-founded productivity startup and achieved 20k signups in 12 months. Developed macOS and iOS clients alongside a custom REST backend built from the ground up.
Founder / CTO / Tech Lead at Sea Gull Systems
January 1, 2017 - October 10, 2025Freelancer London, UK. Founded iOS agency delivering 50+ apps to App Store between 2008-2014. Built award-winning apps for EDF Energy, HarperCollins, Dolce & Gabbana, Chanel. 4 apps reached #1 in category, 3 featured by Apple. Delivered 25 major projects over 6 years, driving consistent profitability through strategic project management and resource allocation.
Senior Mac Developer / Tech Lead at MyHeritage
January 1, 2015 - October 10, 2025Full-time London, UK / Israel. Assembled and led distributed team across UK, Russia, Israel. Delivered polished Mac app for family tree and genealogy. Integrated Obj-C, Obj-C++, and C++ layers with Sea Gull Framework.
CTO / Co-Founder at Kind Network
March 1, 2008 - October 10, 2025Full-time London, UK. Built a team of 10 developers, created social genealogy web app. Acquired by MyHeritage within 18 months. Delivered scalable MVC-based PHP genealogy platform in 17 languages.
Founder / PHP Developer at Sea Gull Framework
January 1, 2012 - October 10, 2025Freelancer Remote. Created open-source PHP framework, 1M+ downloads, 2k active devs, 4k commits, 25k ML messages.
Mobile Team Lead at Global Relay
April 20, 2025 - October 10, 2025Scaled the mobile team from 1 to 20 engineers in 18 months, accelerating iOS delivery and technical maturity. Delivered a greenfield compliant search app using Swift, TCA, and SPM. Designed modular architecture that improved coder usability by 80% and halved integration time. Achieved 82% test coverage and automated CI/CD with Jenkins. Partnered with stakeholders to shape product direction and road map priorities.
iOS Architect at Lloyds Banking Group
March 20, 2021 - October 10, 2025Reduced compile times from 23 minutes to 8 minutes. Implemented SMS 2FA flows and fixed session timeout issues. Maintained a large-scale iOS banking codebase in Swift 5. Migrated codebase to MVVM and introduced extensive unit test coverage.
Senior iOS Developer at Sun Life Financial
August 20, 2018 - October 10, 2025Oversaw a team of iOS developers on a major user-facing app. Migrated architecture to MVVM and enhanced test coverage; led backend/frontend integration work.
Co-Founder / Mac Developer at Doris Productivity
January 2, 2018 - October 10, 2025Co-founded Doris Productivity app. Developed macOS and iOS clients with a REST backend; led product decisions and architectural direction; built an open-source framework and contributed to multiple apps across platforms.
Founder / PHP Developer at Sea Gull Systems
January 20, 2012 - October 10, 2025Founded Sea Gull Systems, delivering PHP-based solutions and open-source PHP framework; built and maintained web/mobile backends and client apps; grew team and project portfolio.
CTO / Co-Founder at Kindo Network
March 1, 2008 - October 10, 2025Co-founded Kindo Network, built a social genealogy app; assembled a team of 10 developers; delivered scalable MVC-based PHP platform in 17 languages; led product and engineering.
Senior Mac Dev / Tech Lead at MyHeritage
January 1, 2015 - October 10, 2025Led Mac development for major projects; contributed across UK/Israel teams; delivered polished Mac apps and led shipping.
Education
Bachelor of Fine Arts (BFA) at Concordia University Montreal, Canada
September 1, 1990 - July 1, 1994BFA at Concordia University Montreal, Canada
September 1, 1990 - July 1, 1994BFA at Concordia University
September 1, 1990 - July 1, 1994Qualifications
Industry Experience
Software & Internet, Media & Entertainment, Professional Services, Other
Skills
Experience Level
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Beginner
Hire a App Developer
We have the best app developer experts on Twine. Hire a app developer in London today.