Full Stack Development Consultant (Mobile, Web, and Integration)

About the role

We are looking for an experienced independent consultant to design, build, test, and hand over a production‑ready cross‑platform mobile app, a companion web app, and a shared backend. The solution must integrate with an external DHIS2 instance and provide single sign‑on through Keycloak. The engagement is full‑time for three months in Gaborone.

Key responsibilities

• Develop a single codebase mobile application for Android and iOS with offline‑first data capture, background sync, conflict resolution and low‑end device optimisation.
• Create a responsive web application that shares domain logic and design system with the mobile app, implementing role‑based views and server‑side permission enforcement.
• Build and maintain backend services in C# (.NET) and Python, exposing versioned REST APIs documented with OpenAPI.
• Integrate the platform with DHIS2 via its Web API, handling metadata alignment, tracker and aggregate data flows, and implementing idempotent, resumable synchronisation with robust error reporting.
• Implement SSO across mobile, web and backend using Keycloak, configuring realms, clients, scopes, OIDC/OAuth2 flows (including Authorization Code with PKCE) and managing token lifecycle.
• Address non‑functional requirements such as performance, security, monitoring, and documentation to enable the internal team to operate and extend the platform.

Required profile

• Independent consultant able to work full‑time and dedicated for a 12‑week fixed‑term contract.
• Proven experience delivering end‑to‑end full‑stack solutions that include mobile, web and backend components.
• Familiarity with DHIS2 integration and Keycloak SSO implementations.
• Ability to produce clear technical documentation and handover materials.

Required skills

• C# and .NET
• Python
• RESTful API design and OpenAPI documentation
• Cross‑platform mobile development (Android & iOS)
• Responsive web development
• Relational database design, migrations and indexing
• DHIS2 Web API integration
• Keycloak, OIDC, OAuth 2.0, PKCE
• Offline‑first data handling and background synchronization