Marcin Bieda Freelance Senior iOS Engineer / Consultant

Swift / SwiftUI / UIKit / Product Delivery

Freelance Senior iOS Engineer for fast, stable product delivery.

I help product teams ship iOS features faster, modernize legacy codebases, and improve app performance without sacrificing code quality.

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Available for freelance and consulting work / Europe time zone friendly / Remote worldwide

iOS Development Services

Hands-on execution and technical leadership across the full iOS product lifecycle.

iOS App Development (Swift, SwiftUI, UIKit)

Feature design, implementation, QA collaboration, and release support end to end.

Legacy iOS Modernization

Migrate risky code paths, reduce tech debt, and improve maintainability safely.

Performance and Stability Optimization

Profile bottlenecks, reduce crashes, and improve launch time and runtime smoothness.

Fractional iOS Tech Lead and Mentorship

Architecture reviews, code standards, pairing, and pragmatic team-level guidance.

How I Work

A delivery process designed for speed, clarity, and low operational risk.

  1. 1. Fast Technical Discovery

    Audit architecture, release pain points, and backlog constraints in your existing app.

  2. 2. Scoped Delivery Plan

    Define clear milestones, acceptance criteria, and risk mitigation for each sprint.

  3. 3. Implementation and Collaboration

    Ship production-ready code with transparent communication and practical trade-offs.

  4. 4. Release and Handover

    Support rollout, monitor behavior, and leave maintainable patterns for your team.

Selected Engagement Examples

Representative project situations I handle in active client work.

Legacy App Stabilization Before Major Release

Joined a mature iOS product with release blockers in crash-prone flows and brittle dependencies. Delivered targeted refactors, improved observability, and supported a safer release cycle.

Crash reduction Dependency cleanup Release hardening

SwiftUI Migration With Minimal Delivery Disruption

Helped a team modernize high-impact UIKit screens to SwiftUI in phases, while keeping feature delivery moving and preserving product behavior.

Incremental migration Architecture alignment Team mentoring

Performance Tuning for Critical User Journeys

Diagnosed UI lag and memory pressure in frequently used app paths, then introduced focused optimizations and validation practices to keep improvements durable.

Instruments profiling Memory optimization UI responsiveness

Proof and Technical Focus

Experience areas where teams usually need senior iOS support the most.

Delivery Highlights

  • 15+ years building and shipping iOS apps.
  • Hundreds of production App Store releases across multiple products.
  • Hands-on work with both startup MVPs and mature enterprise codebases.
  • Reliable collaboration with product, design, QA, and backend teams.

Technical Areas

  • Swift, SwiftUI, UIKit, Combine, async/await, and modern concurrency.
  • Modular architecture, dependency management, and CI/CD workflows.
  • Crash reduction, memory profiling, and UI responsiveness optimization.
  • Bluetooth, maps, media, and real-time data application domains.

FAQ

Common questions about iOS consulting, engagement model, and delivery approach.

Do you work with startups, scale-ups, and enterprise teams?

Yes. I adapt to team size and stage, from early product discovery to stabilization of large production codebases.

Can you join an existing iOS project without a full rewrite?

Yes. Most engagements start with targeted improvements and incremental modernization, not full rewrites.

Do you provide short advisory sessions as well as implementation?

Yes. I offer architecture and performance advisory sessions, and I can also execute the agreed implementation work.

Contact

Tell me about your iOS project, current bottleneck, and timeline.

Best direct contact: hello@dbest.pl

LinkedIn: marcin-bieda

Location: Poland (remote worldwide collaboration)