Senior iOS Consultant for High-Scale, Revenue-Critical Native Apps

Doug modernizes and stabilizes iOS codebases—especially legacy systems and critical flows—so teams can ship features without risking crashes, regressions, or rewrites.

Native iOS Swift SwiftUI Objective-C Legacy modernization Rescue & stabilization Architecture that scales teams Performance & test strategy

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Engagements: modernization, rescue, feature delivery, augmentation

Where this is most valuable

When reliability and velocity both matter

Doug is brought in when the stakes are high: revenue-critical flows, large user bases, brittle legacy code, or teams that need scalable architecture without slowing delivery.

Checkout / payments Legacy Objective-C → Swift Crash / regression risk Multi-team feature development

Industries: e-commerce, enterprise, consumer, healthcare, outdoor.

Services

Legacy iOS Modernization

For teams constrained by technical debt, brittle architecture, or Objective-C/Swift coexistence.

Architecture assessment and modernization roadmap
Incremental refactors that keep shipping
Patterns that other engineers can adopt

Rescue & Stabilization

For critical flows suffering from crashes, performance issues, or release-blocking risk.

Rapid root-cause analysis and stabilization
Guardrails: tests, baselines, safer structure
Clear risk communication and tradeoffs

Feature Delivery at Scale

For teams needing senior execution without long onboarding.

Hands-on implementation in Swift / mixed codebases
Performance and maintainability built-in
Mentoring to raise team capability

Selected Case Studies

Walmart · 2020–2025

Principal Software Engineer — iOS Checkout Lead / Mobile Architect

Built a production-grade foundation for a checkout initiative that needed startup-speed delivery inside a Fortune-scale environment.

~85% test coverage 99.9% crash-free checkout Enabled parallel teams

Designed scalable native architecture for a checkout plugin so multiple teams could add features without breaking core flows—while driving stability and reliability.

McGraw Hill · 2023

iOS Engineer / Data Analyst

Enabled rapid experimentation for a new learning platform by integrating analytics across iOS, Android, and web.

Cross-platform consistency Reliable pipelines Faster product learning

Partnered with analysts to integrate tooling and implement event pipelines feeding data lakes—supporting data-driven iteration without slowing feature delivery.

Sam’s Club · 2017–2020

Senior iOS Engineer

Modernized a legacy codebase to unlock product and design velocity while improving maintainability.

Reactive architecture Faster feature development Team scalability

Transitioned from a simplistic architecture to a reactive model (RxSwift) and rewrote key features to match—so the broader team could ship faster and more safely.

How Doug Works

Principles

Clarity and risk reduction, especially in high-impact user flows.
Pragmatic modernization that keeps releases moving.
Architecture for team scale—patterns that enable parallel development.
Tradeoffs made explicit, with direct communication on risk and timeline.

Core Strengths

Swift and Objective-C migration
App architecture and modularization
Performance and reliability engineering
Test strategy and maintainable patterns

Ideal first conversation

If you can describe your constraints or the failure modes you’re seeing, Doug can quickly outline a plan: what to stabilize first, what to refactor next, and how to keep shipping while the codebase improves and grows.

Preferred contacts: engineering leaders, mobile leads, or product partners who can speak to technical constraints and delivery goals.

Contact

Email or text is preferred for first contact. Doug typically is available US-Eastern hours (8am–6pm).

Currently accepting new engagements Flexible engagement length

Email: dwsjoquist@ivygulch.com Text: (937) 725-8126

Suggested first message: app context, current constraints, timeline, and the top 1–2 risks you want addressed.