Mark Johnson
Independent Contractor at Sandbar
Blacksburg, Virginia, United States
Summary
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RockstarMark Johnson is a seasoned iOS engineer with over a decade of experience building and modernizing mobile products, currently contributing to iOS Foundation at Square. His career spans startups and established companies—leading mobile teams at Supersapiens, rebuilding clients in Swift at Proscape, and shipping iOS features at Block.one and Doximity—demonstrating deep expertise in Swift, Objective-C, encryption, sync, and media rendering. He has a strong background in systems-level engineering from earlier C/C++ and .NET roles, which informs pragmatic, performance-minded mobile architecture decisions. Known for taking sole ownership of substantial rewrites and mission-critical features, he blends hands-on implementation with cross-functional leadership. Based in Blacksburg, Virginia, he brings a long arc of product-focused engineering that pairs legacy-system fluency with modern iOS best practices.
10 years of coding experience
28 years of employment as a software developer
Github Skills (36)
kotlin10
ios10
reactive10
functional-testing10
android-app10
android10
state-machine10
swift10
ruby9
automation9
mobile9
android-apps9
kotlin-library9
cocoapods8
fastlane8
Programming languages (7)
Github contributions (5)
EOSIO/eosio-swift-ecc
Oct 2019 - Dec 2020
Swift utilities for working with keys, cryptographic signatures, encryption/decryption, etc.
Contributions:1 release, 2 reviews, 6 PRs in 1 year 1 month
decryptionencryptionswift
square/workflow-swift
Feb 2022 - Nov 2022
A Swift and Kotlin library for making composable state machines, and UIs driven by those state machines.
Contributions:9 releases, 139 reviews, 90 commits in 9 months
kotlin-librarystate-machineswiftreactiveios
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