Senior IOS Engineer - Contractual

About us:

Working at Tech Holding isn't just a job, it's an opportunity to be a part of something bigger. We are a full-service consulting firm that was founded on the premise of delivering predictable outcomes and high-quality solutions to our clients. Our founders and team members have industry experience and have held senior positions in a wide variety of companies – from emerging startups to large Fortune 50 firms – and we have taken our combined experiences and developed a unique approach that is supported by the principles of deep expertise, integrity, transparency, and dependability.

Responsibilities

• Critical thinker who can anticipate potential pitfalls and suggest improvements, especially around data correctness (timezone, currency, channel-specific filters) and on-device analytics performance.
• Contribute to the codebase, and ensure that the acceptance criteria have been verified before sending the ticket to QA.
• Build new features from the ground up — KPI dashboards, drill-down views, filter panels, period comparisons, and data-visualization screens — while collaborating closely with product, design, and engineering teams.
• Collaborate with onsite and remote engineering teams to produce clean reusable SwiftUI / MVVM code, and provide constructive criticism through code reviews.
• Work with the team lead and the Product team and turn Product requirements into actionable technical stories with well-defined technical specifications and details.
• Work with backend, data, and analytics engineers to discuss Parquet schemas, Firebase Storage sync flows, and SQL / DuckDB query requirements needed to power the iOS app.
• Maintain and enhance the existing code by fixing bugs and monitoring app performance using Instruments (Time Profiler, Allocations, Leaks).
• Implement and improve offline-first sync — Parquet download from Firebase Storage, local caching, and DuckDB import.
• Provide feedback on architecture design and decisions on how to scale mobile applications as data volume and feature surface grow.
• Provide concise documentation that other mobile developers can easily understand.
• Own App Store releases — code signing, provisioning, TestFlight, and App Store Connect submissions.

Requirements

• 5+ years of iOS development experience, including a strong familiarity with Apple frameworks and object-oriented (and protocol-oriented) design best practices.
• A self-starter and fast learner who can adapt to the latest industry trends and technologies.
• Strong experience building applications in Swift (Swift 5.8+), including Swift Concurrency (async/await, actors, @MainActor).
• Hands-on experience with SwiftUI (iOS 17.6+) — state management (@State, @StateObject, @ObservedObject, @EnvironmentObject, @Binding), navigation, view composition, and custom layouts.
• Solid grasp of MVVM architecture and clean separation of Models / ViewModels / Views / Services.
• Hands-on integration experience with Firebase — Authentication, Firestore, Storage, and Analytics.
• Experience implementing Sign in with Apple and Google Sign-In flows.
• Comfortable working with SQL and embedded / local databases (DuckDB, SQLite, Core Data, or Realm — DuckDB / Parquet exposure is a strong plus).
• Experience with Combine or async-await based reactive data flow.
• Familiar with Swift Package Manager for dependency management.
• Proficient with Xcode 16+, debugging with LLDB, and performance profiling with Instruments.
• Knowledge of building and testing large-scale, data-heavy iOS apps and codebases (BI dashboards, analytics, or reporting apps) is a strong bonus.
• Exposure to offline-first sync patterns, file I/O, and caching strategies.