Caleb Grimah
Senior Software Engineer
Full-stack, React Native, Android, and connected-TV engineer.
I build production software across mobile, web, backend, and large-screen platforms. My work spans streaming products used by millions, healthcare systems, e-commerce workflows, offline-first Android applications, and full-stack business tools.
Profile
I am a senior software engineer with 7+ years of experience building production web, mobile, backend, and connected-TV applications, with expertise across Kotlin, Java, React Native, React, Flutter, TypeScript, Node.js, and Spring Boot. I have worked across streaming, healthcare, e-commerce, offline-first systems, and biometric integrations.
I work primarily with Kotlin, Kotlin Multiplatform, Java, JavaScript, TypeScript, React, React Native, Flutter, Node.js, Express, Spring Boot, REST APIs, and database-backed systems. I care about maintainable implementation, performance, reviewable architecture, testing, and practical delivery across real product constraints.
I also use AI-assisted engineering workflows for code exploration, refactoring, debugging, test generation, documentation, and technical research while keeping human review and production-quality judgment in the loop.
- Location
- Abuja, Nigeria
- Primary domains
- Streaming, healthcare, mobile, backend services, connected TV
- Core stack
- React Native, React, Android, Kotlin, Kotlin Multiplatform, Java, TypeScript, Node.js, Express, Spring Boot
Current Work
Senior Software Engineer, Endeavor Streaming
Remote, October 2024 - Present
Build and ship production streaming experiences across mobile, web, and connected-TV platforms, contributing to the Vesper direct-to-consumer video platform ecosystem.
- Build and maintain React Native and React applications using JavaScript and TypeScript across phones, browsers, and large-screen television environments.
- Develop reusable cross-platform components and features that adapt across device classes, screen sizes, input methods, navigation models, and performance constraints.
- Implement and refine navigation, interaction patterns, layouts, and platform-aware user experiences for mobile, web, and connected-TV applications.
- Diagnose production issues and optimize application performance across devices with different processing power, memory capacity, rendering capabilities, and network conditions.
- Work across feature development, integration, testing, debugging, release, and production support to deliver reliable direct-to-consumer streaming experiences.
- Review production code and provide implementation feedback focused on correctness, maintainability, performance, architecture, and engineering best practices.
- Mentor junior engineers through code reviews, debugging sessions, technical guidance, implementation feedback, and knowledge sharing.
- Collaborate with product, design, QA, and engineering teams throughout the development lifecycle to deliver production-ready features.
- Use AI-assisted engineering workflows for code exploration, refactoring, debugging, test generation, documentation, and evaluating implementation approaches while keeping human review and production-quality standards in the loop.
- Platform: Vesper direct-to-consumer streaming platform
Previous Experience
Software Engineer, eHealth Africa
Kano, Nigeria, November 2019 - May 2024
Built and maintained production healthcare software across mobile, web, backend, and cross-platform environments, contributing to patient-facing products, healthcare operations, and digital commerce workflows connected to EHA Clinics.
- Developed and maintained cross-platform mobile features for Android and iOS using React Native, plus additional mobile work across Flutter and native Android.
- Integrated mobile workflows with REST APIs and backend services supporting patient, clinical, commerce, and healthcare operations.
- Implemented healthcare workflows covering appointments, patient information, medical records, laboratory services, medication and pharmaceutical ordering, payments, telemedicine, and patient communication.
- Built responsive web interfaces using React, JavaScript, and TypeScript for patient-facing and internal healthcare workflows.
- Developed Node.js and Express backend services, including REST APIs, server-side business logic, data access, and application integrations.
- Worked on Health-Mate, Ehacare, and GetCare across hospital management, patient engagement, online healthcare services, healthcare commerce, and transactional workflows.
- Optimized application and database interactions to improve reliability, response times, and production behavior.
- Investigated and resolved issues across frontend, backend, mobile, API, database, and integration layers.
- Participated across requirements analysis, technical implementation, integration, testing, debugging, release, and ongoing production support.
- Products: Health-Mate, EHA Clinics, EHA Informatics, and GetCare
Android Developer, Teal Technology Service (IBM OCP JV)
Abuja, Nigeria, April 2019 - April 2020
Developed and maintained Udongo, an offline-first Android application designed to support agricultural extension agents operating in environments with limited or unreliable internet connectivity.
- Designed and developed native Android features using the Android SDK, with a strong focus on reliability, usability, and performance on constrained mobile devices.
- Built and maintained offline-first data workflows, enabling agricultural extension agents to capture, access, and manage information without an active internet connection.
- Implemented local data persistence and background synchronization workflows to synchronize locally captured data with backend services when connectivity became available.
- Designed application flows to handle intermittent connectivity, synchronization failures, retries, and data consistency without disrupting field operations.
- Integrated application components with backend APIs and supported the end-to-end flow of data between mobile devices and remote services.
- Improved Android version compatibility, application responsiveness, stability, and performance, particularly on lower-specification and resource-constrained devices.
- Investigated and resolved application crashes, synchronization issues, device-specific bugs, and other production problems through systematic debugging and testing.
- Worked closely with the team to translate requirements into production-ready mobile features and participated in implementation, integration, testing, debugging, and release activities.
- Contributed to maintaining a reliable mobile experience for users working in remote and connectivity-constrained agricultural environments.
- Application:
ng.udongo.android
Software Engineer, Biosec Solutions
Abuja, Nigeria, April 2018 - May 2019
Built and maintained full-stack business applications spanning frontend, backend, mobile, and persistence layers, with a strong focus on secure, reliable, and offline-capable solutions for real-world business environments.
- Designed and developed backend services and REST APIs using Spring Boot, implementing business logic, data access, integrations, authentication, and application workflows.
- Developed native Android applications using the Android SDK and Kotlin/Java, delivering business-critical mobile applications for field and operational use.
- Built offline-first applications capable of operating reliably in environments with limited or intermittent connectivity, including local data persistence, synchronization, and recovery workflows.
- Integrated biometric and fingerprint hardware/software SDKs, including Neurotechnology fingerprint and biometric SDKs, to support biometric enrollment, identification, verification, and device integration.
- Worked across the full application stack, including frontend interfaces, backend services, databases, APIs, third-party integrations, and mobile applications.
- Participated throughout the software development lifecycle, including requirements analysis, technical design, architecture discussions, implementation, integration, testing, debugging, deployment, and release.
- Designed and implemented integrations between mobile applications, backend services, biometric devices, and external systems while ensuring reliable communication and data consistency.
- Investigated and resolved complex integration, performance, connectivity, and production issues across mobile, backend, database, and hardware-integration layers.
- Collaborated with stakeholders and development teams to translate business requirements into maintainable technical solutions and production-ready features.
- Contributed to improving application reliability, maintainability, and scalability through code reviews, refactoring, testing, debugging, and architectural improvements.
- Company: Biosec Solutions
What I Build
Cross-platform product surfaces
React Native, React, Flutter, Kotlin Multiplatform, and native Android interfaces for mobile, web, and TV contexts, with attention to input model, screen size, and release reliability.
Backend-connected applications
Node.js, Express, Spring Boot, REST API integration, data access flows, transactional workflows, and client/server debugging across production web and mobile products.
Offline-first mobile workflows
Android applications designed to keep core field operations available during poor connectivity, then synchronize cleanly when networks return.
Engineering delivery
Code review, performance diagnosis, regression testing, implementation planning, production support, technical mentoring, and AI-assisted development workflows.
Selected Work
Vesper Streaming Platform
Vesper is Endeavor Streaming's platform for building and operating direct-to-consumer video experiences. My work includes reusable cross-platform features, large-screen interaction patterns, performance improvements, and production delivery across mobile, browser, and connected-TV environments.
Health-Mate
Patient-facing mobile application supporting appointments, medical records, lab services, pharmaceutical ordering, health tracking, payments, and other digital healthcare workflows. I contributed mobile features, API integration, testing, debugging, and production maintenance.
URLs: https://play.google.com/store/apps/details?id=ng.eha.healthmate&hl=en_GB and https://erp.eha.ng/services/informatics
EHA Clinics Platform
Web and backend systems supporting patient-facing and internal healthcare operations. Work included responsive React interfaces, Node.js/Express services, REST APIs, data access, integration paths, and reliability improvements for healthcare workflows.
URLs: https://www.eha.care/ and https://erp.eha.ng/services/informatics
GetCare
Healthcare commerce and online-services platform for medication purchases, appointments, telehealth, frontend/backend integration, and transactional workflows. I worked across client and backend paths used by patients and operations teams.
Udongo
Android app for agricultural extension agents. I implemented offline-first workflows, local data management, API synchronization, Android UI features, compatibility improvements, testing, debugging, and performance work for constrained mobile devices.
Reference: Android package ng.udongo.android
Biosec Business Applications
Full-stack business applications for an identity-management and technology consultancy. I delivered features across UI, business logic, persistence, integration, testing, debugging, and release workflows.
Product Links
- Portfolio page: https://thenorthstar.tech/calebgrimah/
- Resume PDF: https://thenorthstar.tech/assets/docs/caleb-grimah-resume.pdf
- GitHub: https://github.com/calebgrimah
- LinkedIn: https://www.linkedin.com/in/caleb-grimah-8678aa122/
- Primary email: caleb.grimah@gmail.com
- Alternate email: caleb.grimah@arcadereality.org
- Endeavor Streaming Vesper: https://www.endeavorstreaming.com/platform/
- Health-Mate on Google Play: https://play.google.com/store/apps/details?id=ng.eha.healthmate&hl=en_GB
- EHA Clinics: https://www.eha.care/
- EHA Informatics: https://erp.eha.ng/services/informatics
- GetCare: https://getcare.eha.ng/
- Biosec Solutions: https://biosec.com.ng/
Technical Focus
Languages: Kotlin, Java, JavaScript, TypeScript, Python, HTML, CSS
Mobile: React Native, native Android, Kotlin Multiplatform, Flutter
Web and backend: React, Node.js, Express, Spring Boot, REST APIs, database-backed services
Engineering: full-stack development, cross-platform development, offline-first architecture, responsive design, performance optimization, testing, debugging, code review, API integration, technical mentoring, AI-assisted development
How I Work
I am strongest in product environments where the engineering work spans more than one layer of the stack. I can move from a mobile defect to the API behavior behind it, from a performance issue on a low-end Android device to the data shape causing it, or from a TV navigation requirement to a reusable cross-platform component.
My default working style is practical and reviewable: clarify the user flow, understand the failure mode or product requirement, make the smallest coherent implementation, test the affected path, and leave the code easier to reason about than I found it.
I use LLM coding tools as part of my engineering workflow for codebase exploration, alternate implementation research, test-case drafting, refactoring support, and documentation. I treat AI output as draft material that still needs engineering review, system context, and production judgment.
Education
B.Sc. Computer Science
Madonna University, Rivers, Nigeria
Contact
For engineering roles, product work, consulting, or technical collaboration:
- Email: caleb.grimah@gmail.com
- Alternate email: caleb.grimah@arcadereality.org
- GitHub: @calebgrimah
- LinkedIn: Caleb Grimah
- Resume: Download PDF