iOS & SDK engineering
Native iOS features and SDKs that third-party developers integrate.
- Swift, SwiftUI, UIKit, Objective-C
- UIKit → SwiftUI migrations
- Swift Concurrency, fixing race conditions
- SDK API design & integrator support
Available for part-time projects
Denis Makarau
Senior iOS & SDK Engineer. I build mobile SDKs and apps that other teams depend on, and the test infrastructure that keeps them reliable. Alongside my role at Zendesk, I take on a small number of part-time freelance projects and workshops.
- 11+ yearsin software engineering, most of it in mobile
- 5 yearson a widely used iOS SDK, first in test, then in development
- 7+ yearsof mobile test automation on iOS and Android
- 100+real devices in CI, in a device-farm setup I built
How I can help
I join teams as a senior engineer who owns a problem end to end: architecture, delivery and the tests that prove it works.
Mobile test automation
Seven years of test automation, from first framework to CI at scale.
- XCUITest, Espresso, Appium
- Device farms (BrowserStack), Fastlane
- Stabilizing flaky test suites
- CI/CD for release confidence
AI coding agents, done safely
Workshops for teams adopting AI coding agents without losing quality.
- Working with Claude Code & agents
- Verifying what an agent claims
- Workshop design & facilitation
- MCP & agentic tooling
Experience
From QA automation to senior iOS engineering on a widely used customer service SDK.
ZendeskSep 2021 – present
Munich
Munich
Senior Software Engineer, iOS SDK
Jan 2023 – present
- Designed the iOS side of the SDK's analytics pipeline, from event tracking in Swift to the data platform.
- Built AnalyticsKit, a modular analytics layer used inside the core SDK.
- Reworked the SDK's concurrency model with Swift Concurrency and fixed long-standing race conditions.
- Led the UIKit → SwiftUI migration of core SDK screens.
- Security Champion for the iOS team: audits, vulnerability reviews and secure-by-design practices.
- Maintain legacy Objective-C components and keep upgrades smooth for enterprise customers.
Senior Development Engineer in Test
Sep 2021 – Jan 2023 · promoted to Senior Software Engineer
- Architected an XCUITest automation framework with Fastlane and CI/CD for every SDK release.
- Migrated 500+ UI tests from deprecated EarlGrey to XCUITest.
- Moved test execution to BrowserStack with parallel runs on 100+ real devices.
- Led the cross-platform test strategy (iOS + Android): snapshot, integration and UI tests.
Nebius AcademyAug 2026 – present
Part-time
Part-time
AI Technical Instructor & Workshop Lead
Live workshops for a corporate cohort of software engineers
- Teach engineers to work with AI coding agents without trusting unverified claims.
- Design hands-on exercises (CI failure triage, test audits) with facilitator kits and supporting tooling.
ProSiebenSat.1 DigitalApr 2019 – Sep 2021
Munich
Munich
Senior QA Automation Engineer
High-traffic video player on iOS, Android and Web
- Built the cross-platform test automation infrastructure from scratch (XCUITest, Espresso, Selenium WebDriver), fully integrated into GitLab CI/CD.
Virtual Solution AGJun 2018 – Apr 2019
Munich
Munich
Software Test Automation Engineer
SecurePIM, a secure enterprise mobile app
Western UnionMar 2017 – May 2018
Vilnius
Vilnius
Senior QA Automation Engineer
Built the mobile test automation framework for a money transfer app (iOS + Android)
EPAM SystemsFeb 2015 – Feb 2017
Minsk
Minsk
Software Test Automation Engineer
Selenium frameworks across enterprise projects; Junior to Mid-level in 12 months
Projects
Things I build on my own time, end to end.
SmartKauf
Beta · iOS & AndroidA shared shopping list app: works offline, syncs to the cloud, lists are shared with family and friends, and items can be added by voice with an LLM parsing the dictation.
Skills
- iOS
- Testing & CI
- Cross-platform & backend
- AI tooling
- Practices
Background
Certifications
- Claude Code: Agentic Coding for Professional Developers
- Model Context Protocol (MCP): Hands-On with Agentic AI
- Mastering Swift Concurrency
Education
- Belarusian State Economic University B.A. Business Economics
Volunteering
- Volunteer firefighter, Freiwillige Feuerwehr Neufahrn 2025 – present
Languages
- Russian Native
- English Professional
- German B2
- Spanish Basic
Working together
- EngagementPart-time freelance projects and workshops
- LocationRemote
- ContractFreelancer (Freiberufler), directly or via agencies
- RateOn request
- Work permitEU citizen, no permit needed
Let's talk about your project
Need a senior iOS engineer, help with an SDK, or a test automation setup that your team can trust? Recruiters and consultancies are welcome: please include the scope, duration and start date. Prefer a call? Email me and I'll suggest a time.