Senior Mobile Systems Engineer
Specializing in video playback, developer SDKs, and mobile security. Building pocket-sized solutions to bigger problems.
SELECTED WORK
Selected work across playback, SDK architecture, and mobile product engineering.
Developer tooling · Open source
A playback diagnostics toolkit, motivated by my experience investigating playback issues at Storyteller.
THE WORKBuilt structured playback telemetry around existing Media3/AVPlayer players, keeping playback and lifecycle control with the host app.
Mobile security · Open source
An Android library that collects device-integrity signals to identify root, runtime instrumentation, emulators, unlocked bootloaders, and weakened platform security.
THE WORKDesigned a coroutine-based Kotlin API, configurable risk policies, versioned evidence models, and native NDK checks across four Android architectures.
SDK engineering · Video infrastructure
Native Android infrastructure for integrating vertical video feeds, stories, advertising, and interactive media into consumer apps.
THE WORKBuilt developer-facing capabilities across media playback and reusable UI, with an emphasis on integration quality and predictable behavior.
SDK engineering · Commerce
A white-label SDK that adds embedded deals and coupons to Android apps while keeping the host product experience coherent.
THE WORKWorked across SDK architecture, accessibility-driven integration, and the constraints of shipping configurable functionality inside third-party apps.
EXPERIENCE
Product engineering, developer SDKs, and the responsibility of helping teams deliver.
Founding Mobile Engineer
I own mobile architecture across Flutter, Android, and iOS, working with product and design to turn requirements into maintainable features.
Authored the Mobile Engineering Design Document and established GitHub Actions pipelines for repeatable builds and releases.
Senior Android Engineer
Built reusable Kotlin and Compose SDK features for media experiences across Android mobile and TV.
Diagnosed device-specific lifecycle, rendering, and Surface-attachment failures. That playback debugging experience became the catalyst for Framewright.
From playback debugging to FramewrightSenior Android Engineer
Developed a browser-integrated Android SDK for shopping and checkout journeys, with integrations across more than five browser hosts.
Replaced scattered UI state with MVI and structured Coroutines/Flow; integrated MobSF and Detekt into CI/CD and supported code reviews and mentoring.
Senior Mobile Engineer
Delivered insurance management, payments, profile updates, and secure customer data handling in an existing insurance app.
Designed reusable insurance SDKs across Android, iOS, Flutter, and React Native, including configurable insurance purchase journeys.
Mobile Software Engineer & Technical Support
Built Android and cross-platform engagement SDK features with configurable UI and developer-facing APIs.
Supported partner debugging, documentation, and CI/CD improvements.
Mobile Engineering Lead
Led a four-person mobile team building native Android and Flutter products.
Worked across planning, architecture, code reviews, and Google Play releases.
Android Developer
Built modular Java and Kotlin Android applications with REST APIs and real-time WebSockets.
Supported compatibility across Android devices.
Android Developer
Worked on real-time Android features involving camera encoding, networking, and NFC/RFID.
Built performance-sensitive components using C++, the Android NDK, and FFmpeg.
EXPERTISE
Mobile specialist with advanced expertise in building media platforms, fraud prevention and developer tools (SDKs).
Reliable playback across devices, networks, formats, and the awkward edge cases between them.
Device-integrity and content-protection systems designed with realistic threat models and layered controls.
Stable, documented integration surfaces that feel native to the teams adopting them.
Moving teams from ambiguity to durable decisions, quality releases, and shared ownership.
Native and cross-platform mobile development, choosing the platform and framework that fit the product.
Build automation, release workflows, and app services that support reliable mobile delivery.
ABOUT DAVID
Mobile engineer.
SDK builder.
Curious about the difficult parts.
I’m David Rufai, a software engineer focused on mobile systems. My work has taken me from camera encoding and native Android components to consumer products, reusable SDKs, and mobile architecture across platforms.
At Storyteller, I investigated playback failures involving device lifecycles, rendering, and Surface attachment. That experience motivated Framewright, my open-source playback diagnostics toolkit. DeviceTrust is another part of my independent work, focused on device integrity and risk signals.
Today, I lead mobile architecture at Knit. Alongside implementation, I work on the decisions that help teams deliver: engineering standards, release workflows, code reviews, and collaboration with product and design.
HOW I WORK
At Storyteller, I used Crashlytics and Baseline Profiles to investigate production issues and performance. Framewright extends that interest in understanding playback through structured telemetry.
My SDK work includes both building integrations and helping partners debug them. With Framewright, the host application keeps control of its player while adding diagnostics around it.
At Knit, I established repeatable build and release pipelines. At Kindred, I brought static analysis and security checks into CI alongside architecture improvements.
AI IN PRACTICE
I’ve used AI-assisted engineering while building Framewright and working at Knit and Storyteller. That spans an independent developer tool, mobile product architecture, and a production media SDK. At Knit, I use Claude Code and Codex for implementation, refactoring, and tests, with hands-on verification.
The biggest benefit for me is how much faster I can ship. That starts with planning, continues through implementation, and extends to automating release workflows. AI helps me move through more of the delivery process with less manual effort.
The friction I encounter most often is overengineering and missing context. AI can introduce more structure than a task needs, or propose a change without understanding how it fits into a larger codebase. Part of my job is keeping the solution proportionate and making sure it belongs in the system around it.
Hallucinations used to be a major issue in my workflow. More recently, I’ve seen a substantial reduction as models have become more capable and I’ve split larger tasks into smaller, straightforward units. That’s an improvement I’ve noticed in my own work; I still verify the output.
AI assistance helps me turn a plan into working changes sooner. The speed improvement starts before I write the implementation.
I use AI during implementation and refactoring, reducing manual effort as I work through a task.
The benefit extends beyond writing code. I also use AI assistance to automate release workflows and get changes ready to ship.
AI often overengineers a task. I need to question whether the proposed structure is justified by the actual problem.
A suggestion may address the immediate task without fitting the wider system. Existing architecture and constraints need to remain part of the decision.
I’m especially careful with AI-generated code involving authentication, authorization, or sensitive data. I review the security assumptions and failure paths, including whether access is actually enforced and what happens when checks fail.
I’ve seen a substantial reduction with more capable models and smaller, clearer tasks. I still check the result rather than treating that improvement as a guarantee.
Breaking a large task into smaller, straightforward units has become an important part of how I work with AI. It makes the scope clearer and gives me a more manageable change to review.
I’m responsible for deciding how much complexity a task warrants and how a change fits the existing codebase. AI helps me ship faster; hands-on verification remains part of getting that work ready for release.
START A CONVERSATION
Let’s talk about playback, SDK architecture, or getting a mobile product unstuck.