Senior Swift Engineer
Location: Sunnyvale, California
Duration: 2 Months
Pay: $110/hr - $120/hr (DOE) 

We are building a native macOS application that delivers AI-powered data insights for business users. This is a systems-level contract engagement -- you'll work across AI runtime, platform integrations, deterministic data execution, or adaptive macOS UI depending on your strengths and interests. The architecture is multi-stage pipeline driven, with strict layered dependencies across 20+ Swift Package Manager targets and no shortcuts. The application is a structured, multi-stage pipeline that turns natural language into verified, traceable results. We need engineers who ship real macOS desktop software and take ownership of their technical surface.

Key Responsibilities:

• Own one or more technical surfaces within a native AI pipeline: runtime/orchestration, platform/integrations, deterministic execution, or adaptive UI.
• Design and implement production Swift code within a layered SPM architecture (20+ targets) with strict dependency boundaries from foundation types through orchestration to application layer.
• Build AI orchestration including structured output extraction, multi-stage routing, tool calling, context management, and response synthesis.
• Implement platform integrations -- protocol-based connector clients, enterprise data access, entitlements, sandboxing, identity, and persistence boundaries.
• Build deterministic execution pathways -- joins, aggregations, rankings, filters -- with full data provenance and traceability.
• Develop macOS adaptive UI using SwiftUI with AppKit interop -- desktop windowing, keyboard-first workflows, streaming content updates, state management, and accessibility.
• Write and maintain automated tests using XCTest and Swift Testing frameworks.
• Ensure all shared mutable state uses actors or Sendable value types with correct isolation annotations under Swift 6 strict concurrency.

Minimum Qualifications:

• 5+ years of professional software engineering experience with Swift
• Experience shipping macOS desktop software (not iOS-only)
• Strong understanding of Swift concurrency: actors, async/await, Sendable, structured concurrency, and typed throws
• Experience working within layered, modular SPM architectures with strict dependency management
• Proficiency with protocol-oriented design and dependency injection patterns
• Comfortable with pre-commit hooks, strict linting (SwiftLint, SwiftFormat), and enforced commit conventions

• Swift 6.2, macOS 26+, SPM-only (no Xcode project file)
• 20+ SPM targets across foundation, stage, orchestration, and application layers
• LLM integration and ML inference frameworks for AI-powered features
• XCTest and Swift Testing for test automation
• SwiftLint + SwiftFormat with strict pre-commit enforcement
• Git-based workflow with conventional commits and CI pipeline integration

1. AI Runtime and Orchestration - LLM integration: guided generation, structured output, tool calling, streaming inference - Experience with ML inference frameworks and model orchestration - Token budget management, prompt composition, multistage pipeline orchestration - Evaluation and benchmarking of non-deterministic AI outputs
2. Platform and Integrations - Protocol-based connector/client architectures (SSE, stdio, REST, OData) - macOS system services: process lifecycle management (launchd, SMJobBless), entitlements, sandboxing - Code signing, notarization, and installer packaging for macOS distribution - Enterprise data access patterns and pagination strategies
3. Deterministic Execution and Data Systems - TabularData or equivalent data frame processing in Swift - Joins, aggregations, rankings, filters with provenance tracking - Graph or vector retrieval systems, entity resolution - Schema-driven field matching and query planning.
4. macOS Adaptive UI - Production SwiftUI applications with AppKit interop on macOS - Adaptive layouts, multi-panel desktop windowing, keyboard-first navigation - Streaming UI updates tied to async data pipelines - Accessibility compliance and performance optimization (Instruments profiling)

• Your Swift experience is iOS-only with no macOS desktop shipping experience
• You prefer working in large teams with narrow task assignments
• You are primarily a prompt engineer, backend CRUD developer, or web frontend engineer
• You want to introduce large architectural changes before the existing pipeline model is validated
• You are not comfortable with strict linting, pre-commit hooks, and enforced coding conventions