Software engineer
I turn hard problems into shipped software.
I am a software engineer at Visa, where I ship payment infrastructure and the developer tooling around it. Outside work I built OmniMusik, an iOS music client that puts owned files and streaming services in one library, with a real-time effects chain, cross-device sync, and a web companion on AWS.
Featured project
OmniMusik: one library for music you own and music you stream
An iOS client that merges local files and Spotify into a single library, queue, search and playlist system, designed for Apple Music behind the same interface. Owned files get a real-time effects chain. Playlists sync to a web companion, and both clients run on AWS infrastructure I provisioned in Terraform.
AVAudioEngine graph runs them.Streaming audio plays in a process the app does not own (Spotify's, or the system player's) and hands out no samples. Effects are structurally local-only, and the domain model says so rather than leaving it as a comment.
Two deliberately separate protocols: how a track plays and where it comes from. They don't map one-to-one, and keeping them apart is why adding Spotify touched no existing source or player.
Version-checked writes, an 8-case decision table that shows conflicts instead of picking a winner, and a server epoch so a replaced database can never be read as mass deletion.
Spring Boot / Postgres API on ECS, React companion on CloudFront, Cognito auth, all in Terraform, with keyless CI via GitHub OIDC and a no-NAT network that cut idle cost by about half.
- System designTwelve diagrams (context, the two protocols, playback, the Spotify boundary, sync, auth, the AWS topology), each with the reasoning the diagram can't show.
- Field guideThe whole project in ten minutes, organised by the questions it gets asked.
- Decisions logEvery non-obvious choice, with the alternatives that were rejected and why.
Experience
Where I've worked
Payments infrastructure and the tooling that keeps it shippable.
- Diagnosed a silent failure blocking all resellers on the legacy platform from enabling Cybersource products for merchant accounts by tracing raw upstream API responses using AI to an unpopulated count field the service read as zero; evaluated four fixes on cross-team dependency, latency, and complexity and shipped a single-call solution benchmarked 38% faster with 69× smaller payloads than the leading alternative.
- Redesigned a multi-row, manual merchant transactional configuration workflow for a platform of 5,000 merchants into a single guided React (JavaScript) UI backed by a new event-driven REST endpoint (Vert.x) that publishes a Kafka event per merchant, decoupling request intake from asynchronous downstream execution.
- Built an autonomous UI development AI agent as a Claude Code slash command, orchestrating Jira, GitHub, and Figma MCP servers to take a feature from ticket to open pull request: React component generation, Jest tests, lint remediation with a human-in-the-loop review checkpoint and enforced AI-code compliance tagging for a regulated fintech environment.
- Built a suite of five internal developer tools (Python, Node.js) used by other team members for automating QA report consolidation, natural-language test-data provisioning across five environments and two platform architectures, and Claude Vision AI assisted Cypress test authoring that reduced automated test development times by 80%.
- Developed the React, TypeScript, and Redux frontend alongside Spring Boot REST APIs for a prototype electronic I-9 application, leveraging Spring Cache (
@Cacheable) to store high-frequency reference data and eliminate redundant database queries. - Engineered automated testing frameworks using Cucumber, Selenium, and Java, achieving comprehensive application feature coverage and reducing manual testing effort by 36%.
- Reduced overall runtime of test cycle execution in Jenkins by 41% by refactoring test scripts.
Skills
What I work in
Contact
Say hello
- Email[email protected]
- GitHubgithub.com/obi47n
- LinkedInlinkedin.com/in/obinnaduruaku