Available for iOS, AI & consulting roles

Jacob Relkin

Senior iOS Engineer & Technical Advisor

From iPhone OS 3 to visionOS. 15 years, four acquisitions, apps used by millions.

new york · (845) 475-8517 · jacobrelkin@gmail.com

About

15+ years building iOS products that ship to millions.

Founding engineer at Breathometer — built the platform behind a $1M Shark Tank deal with all five Sharks.

Acquired into Square via Pins, promoted to the Square Register Foundation team powering the flagship POS app. Flagship iOS release at Doximity to 100K+ physicians.

163K+ Stack Overflow reputation — top 0.01%, ~22M people reached.

Craft & Depth
From Bluetooth protocols to polished UI. Low-level systems to performance-critical pipelines.
Ownership & Leadership
Leading teams, mentoring engineers, owning products from architecture through launch.
Systems Thinking
Platform tooling, offline-first architectures, and compliance frameworks built for scale.

Notable Projects

Experience

Independent Practice — Principal iOS Engineer & Technical Advisor
2013 – Present
Embedded engagements across fintech, healthcare, social, IoT, and AI
  • Embedded as senior engineer with 15+ clients shipping production iOS across fintech, healthcare, social, IoT, and AI
  • Currently serving as technical advisor to a venture-backed stealth startup (AGI + payments + vertical SaaS)
  • Delivered production systems spanning real-time chat, payment processing, HIPAA-compliant healthcare, Bluetooth hardware, and on-device ML
15+ clientsConsulting PracticeAdvisor
Bottleshake — Engineering Lead
2016 – 2017
B2B networking platform connecting brands with influencers
  • Hired by CEO as engineering lead—built and managed 5-person cross-functional team owning the full product stack (iOS, web, backend API)
  • Engineered Login with LinkedIn integration that significantly increased new user signups
  • Spearheaded UI/UX redesign and matching algorithm overhaul that meaningfully reduced churn and increased weekly engagement
Full-stack lead5-person team
Square (now Block) — iOS Platform Engineer, Square Register Foundation Teamvia Pins Acquisition
2013 – 2015
Acquired via Pins → promoted to Register Foundation team
  • Built Pins from the ground up—Core Data persistence, sync engine, custom map clustering. Engineering quality led directly to acquisition by Square
  • Post-acquisition, promoted to Square Register Foundation team—owned core libraries, tooling, and shared infrastructure powering the flagship POS app
  • Cut CI build times by over 30% through parallelized builds, test sharding, and caching—saving hundreds of engineering-hours per quarter
  • Prototyped Square Invoices at Hack Week—shipped to production
Platform EngineeringJoined via Acquisition
Breathometer — iOS Engineering Lead
2013 – 2014
Consumer Bluetooth breathalyzer — featured on ABC’s Shark Tank
  • Founding iOS engineer—built the iOS app, Bluetooth stack, and signal processing pipeline
  • Product featured on ABC’s Shark Tank (Season 5)
  • Engineered custom CoreBluetooth GATT profiles, real-time sensor streaming, and BAC calculation algorithms
Founding EngineerHardware + Software
Doximity — Lead iOS Engineer
2011 – 2013
Professional network for physicians — now NYSE: DOCS
  • Led development of v5.0—the major platform release. Shipped Search, DocMail, DocFax, and physician forums
  • Architected a white-label SDK deployed at Stanford, Harvard, Penn, UCSF, and UCSD; established iOS architecture standards adopted company-wide
v5.0 Release LeadNYSE: DOCS
Earlier Roles — Giftiki, Appcelerator, Freeverse
2009 – 2011
  • Giftiki (Lead iOS) — Built social gifting app featured in Apple’s “New & Noteworthy.” Acquired by LaunchRock.
  • Appcelerator (iOS Platform) — One of four core engineers building the Titanium Mobile cross-platform framework (Obj-C/JS runtime bridge).
  • Freeverse (Software Engineer) — Shipped two commercial iOS games starting at age 14.
Apple FeaturediOS since 2009

Technical Skills

ExpertAdvancedFamiliar
Languages
SwiftObjective-CTypeScript / JavaScriptPython
Architecture
MVVM / TCAProtocol-Oriented DesignModular Swift PackagesState Management
Apple Platforms
UI Frameworks (UIKit, SwiftUI)Bluetooth & Hardware (CoreBluetooth)Concurrency & Reactive (Combine, async/await)Data Persistence (SwiftData, Core Data)System Frameworks (MapKit, HealthKit, AVFoundation)Push Notifications & StoreKit
Engineering Practices
Testing (XCTest, UI, Snapshot)Xcode & InstrumentsCI/CD (Fastlane, GitHub Actions)API Integration (REST, GraphQL)
AI-Augmented Development

Shipping production code and tooling faster with AI-assisted workflows—from architecture to implementation.

AI-Augmented Dev (Claude Code)LLM IntegrationPrompt EngineeringCore ML / On-Device AI

Community

Education

Lev Academic Center (Jerusalem College of Technology)— Computer Science

Certifications

Newton Academy iOS Developer Arc Certified Remote Developer

Let’s Talk

Building something for iOS? I’d love to hear about it.

jacobrelkin@gmail.com new york • Remote-friendly