Full
Stack Development Consultant (Mobile, Web, and Integration)
Location: Gaborone, Botswana.
Engagement type: Independent consultant, fixed term contract for services
Duration: 3
months (12 working weeks)
Effort: Full
time and dedicated. Given the duration, this engagement cannot absorb split
availability.
Reports to: Country Technical
Lead
Background
We are delivering a new platform comprising a cross platform mobile
application, a companion web application, and a shared backend. The platform
integrates with an external DHIS2 instance and authenticates all users through
a central Keycloak identity provider.
We are seeking an experienced independent consultant to deliver this
build. The consultant will work as part of our technical team but retains
responsibility for their own deliverables, methods, tools, tax, and statutory
obligations.
Objective of the assignment
To design, build, test, and hand over a production ready platform across
mobile and web, with reliable DHIS2 integration and single sign on across all
client applications, together with the documentation needed for our team to
operate and extend it without the consultant present.
Scope of work
3.1 Cross platform mobile application
Design and build a single codebase mobile application for Android and iOS.
Implement offline first data capture with background synchronisation, conflict resolution, and clear sync state visible to the user.
Optimise for low end devices, intermittent connectivity, and constrained data usage.
Deliver store ready builds, including signing, versioning, staged rollout, and crash and performance monitoring.
3.2 Web application
Build a responsive web application on the same backend, sharing domain logic and design system with the mobile app.
Implement role based views, with permissions enforced on the server and not only in the client.
3.3 Backend services
Build and maintain backend services in C# (.NET) and Python, exposing versioned, documented REST APIs (OpenAPI).
Implement relational data models with migrations, indexing, and query performance considered from the outset.
3.4 DHIS2 integration
Integrate with DHIS2 via its Web API, covering metadata alignment, tracker and aggregate data flows, and scheduled or event driven synchronisation.
Implement idempotent, resumable synchronisation with retry, dead letter handling, and a reconciliation mechanism that proves both systems agree.
Provide auditable error reporting so that any failed record can be traced, explained, and replayed.
3.5 Single sign on with Keycloak
Implement SSO across mobile, web, and backend services using Keycloak.
Configure realms, clients, scopes, and role and group mappings, and implement the correct OIDC and OAuth 2.0 flow for each client type, including Authorization Code with PKCE on mobile and web.
Implement token lifecycle handling: refresh, revocation, session management, secure token storage on device, and service to service authentication.
3.6 Non functional requirements
The consultant is expected to address the following explicitly, not by
implication, in both the solution and the documentation.
- Security. Authentication and authorisation, encryption in transit and at rest, secrets management, least privilege access, and audit logging of all sensitive operations.
- Compliance. Delivery must meet the Botswana Data Protection Act 2024 and any client or sector specific data handling requirements, including data minimisation, consent handling where applicable, and retention rules.
- Resilience. Graceful degradation when upstream systems are unavailable, backup and restore procedures, and defined recovery targets.
- Reliability. Monitoring and alerting, structured logging and observability, load behaviour, and tested rollback procedures.
3.7 Knowledge transfer and handover
Maintain architecture decision records, API contracts, integration runbooks, and environment setup documentation throughout the engagement, not at the end of it.
Conduct handover sessions with our engineering team covering codebase, deployment, integration behaviour, and known issues.
Required qualifications and experience
Essential
- Minimum 3 years delivering production software, including at least one system taken from design through to live release and post release support.
- Strong backend capability in C# / .NET and working proficiency in Python, or the reverse where the second language is genuinely close.
- Demonstrable cross platform mobile delivery in Flutter, React Native, or .NET MAUI, with references to shipped applications.
- Modern web front end experience (React, Angular, Vue, or Blazor).
- Proven experience integrating with third party systems over REST APIs, including authentication, pagination, rate limiting, partial failure, and data reconciliation.
- Hands on implementation of OAuth 2.0 and OpenID Connect, ideally with Keycloak.
- Relational database design and optimisation (PostgreSQL or SQL Server).
- Git, CI/CD, and containerised deployment.
- Ability to engage directly and unsupervised with a client's technical team.
Advantageous
- Direct DHIS2 experience: Web API, tracker programs, custom apps, or metadata packages.
- Health data standards such as HL7 FHIR, or experience in regulated or public sector data environments.
- Offline first sync engine design.
- Keycloak at depth: identity brokering, external identity providers, custom mappers, token exchange.
- Message queues or event streaming, and observability tooling.
- Experience with government or enterprise hosting constraints, including on premises deployment.
Our company provides equal employment opportunities (EEO) to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability or genetics.