Sr. Full Stack Developer

Main Purpose:

Puma Energy is seeking a Full Stack Developer to join its Digital & Technology team, supporting the design, development, and operation of its core digital platform across multiple African markets. The platform handles high-volume transactional operations spanning mobile applications, ERP integrations, payment infrastructure, real-time data pipelines, and cloud-hosted backend services.

This role demands equal strength across backend API engineering, cloud infrastructure, and frontend development. The successful candidate will work across the entire stack: building and maintaining backend services and REST APIs, integrating with ERP and third-party platforms, developing mobile-facing interfaces, and contributing to the cloud data infrastructure that powers operational analytics and reporting.

KEY RESPONSIBILITIES:

API & Service Engineering

• Design, build, and maintain RESTful APIs consumed by mobile applications, ERP systems, partner platforms, and internal operational tools.
• Implement event-driven service patterns using message brokers and event streaming platforms to handle real-time transaction flows with defined latency SLAs.
• Build webhook receivers and outbound event publishers to support bi-directional integration with third-party operational and payment systems.
• Develop batch processing jobs for scheduled data exchange: extraction, transformation, delivery, reconciliation validation, and exception alerting.
• Implement robust API security: OAuth2 / token-based authentication, token lifecycle management, rate limiting, API versioning, and request validation.
• Design idempotent transaction processing services where duplicate events, network retries, or partial failures must not cause data integrity issues.
• Build internal microservices and serverless functions for discrete processing tasks: transaction enrichment, notification dispatch, reconciliation logic, and data transformation.

ERP & System Integration

• Develop and maintain integration layers between cloud-hosted services and ERP platforms via REST API and JSON-RPC; handle authentication, payload mapping, error recovery, and retry logic.
• Build structured data bridges between modern cloud services and legacy ERP or operational systems: field mapping, reconciliation validation, discrepancy detection, and automated alerting.
• Design and implement integration patterns for near-real-time transaction event ingestion from external operational platforms (point-of-sale, forecourt management, payment gateways) into backend services.
• Maintain API client libraries for communication with banking, payment, and third-party operational infrastructure; manage versioning and backward compatibility.

Database & Data Engineering

• Design and maintain relational database schemas (PostgreSQL) for high-volume transactional systems: indexing strategies, partitioning, query optimisation, and schema migration management.
• Build and maintain cloud data pipeline connectors: stream transaction events from backend services into cloud event hubs and downstream data lake layers (Bronze / Silver / Gold Delta architecture).
• Implement data quality controls: validation rules, deduplication logic, lineage tracking, and anomaly detection within ingestion pipelines.
• Write optimised SQL and ORM queries for reporting and operational data retrieval; design materialized views and caching strategies for frequently accessed datasets.

Web & Operational Interfaces

• Build and maintain operational web interfaces used by internal teams: dashboards, transaction management screens, reconciliation tools, and reporting views.
• Develop responsive, accessible frontend components using a modern JavaScript framework (React or Vue); implement state management, lazy loading, and performance optimisation.
• Build data visualisation components for operational and financial reporting: charts, pivot tables, and exportable transaction summaries.
• Develop simplified UI modes for non-technical and lower-literacy end users, using icon-led navigation, minimal text input, and progressive disclosure patterns.

Mobile Application Support

• Contribute to mobile application development (Android / iOS) or hybrid mobile frameworks; build and maintain features across customer-facing and operational mobile apps.
• Implement mobile API integration layers: authenticated API calls, offline caching, background sync, and graceful degradation under poor connectivity conditions common in African markets.
• Build QR code scanning, mobile payment flows, and real-time transaction status features within mobile applications.
• Optimise mobile application performance for low-end Android devices and variable network conditions; implement app size reduction and asset optimisation strategies.

• Design and deploy cloud-hosted backend services on AWS and/or Azure: serverless functions (Lambda / Azure Functions), managed queues, API gateways, and container orchestration.
• Configure and maintain cloud event streaming infrastructure (e.g. AWS Kinesis, Azure Event Hubs) for real-time transaction ingestion from distributed operational sources.
• Manage cloud networking: VPCs, security groups, private endpoints, egress controls, and network policies governing data flow between cloud regions and on-premise systems.
• Build and maintain CI/CD pipelines: automated testing, build, containerisation, and deployment across development, staging, and production environments.
• Implement infrastructure-as-code (Terraform or equivalent) for reproducible environment provisioning across multiple markets.
• Instrument backend services with structured logging, distributed tracing (OpenTelemetry), and metrics collection; integrate with APM platforms for latency, error rate, and throughput monitoring.
• Manage secrets, credentials, and environment configuration securely across multi-market cloud deployments; implement secret rotation and access auditing.

• Write unit, integration, and end-to-end tests for all services and APIs; maintain coverage across critical transaction paths, edge cases, and failure scenarios.
• Participate in and lead code reviews; enforce engineering standards covering security, performance, maintainability, and test coverage.
• Own Git-based version control practices: feature branching, pull request workflow, semantic versioning, and structured release management across multiple concurrent markets.
• Produce and maintain technical documentation: API contracts (OpenAPI/Swagger), architecture diagrams, data flow documentation, integration runbooks, and incident playbooks.
• Provide Tier 2/3 production support: triage and resolve incidents relating to API failures, integration errors, data pipeline issues, and mobile application defects across live multi-market deployments.

SKILLS & COMPETENCIES:

Backend — Essential

• 3+ years backend development experience; strong proficiency in Python and/or Node.js for API and service development.
• REST API design: endpoint design, authentication (OAuth2, JWT), versioning, error handling, and OpenAPI documentation.
• PostgreSQL: schema design, query optimisation, indexing, and migration management.
• Event-driven architecture: message brokers, event streaming platforms, webhook design, and async processing patterns.
• Cloud platform experience (AWS and/or Azure): serverless compute, managed queues, API gateway, and storage services.
• Docker and container-based deployment; CI/CD pipeline configuration and management.

Frontend & Mobile — Essential

• React or Vue.js: component architecture, state management, routing, and performance optimisation.
• Mobile development experience: React Native, Flutter, or native Android/iOS development.
• HTML5, CSS3, and responsive design; familiarity with accessibility standards.
• RESTful API integration from frontend and mobile clients: authentication flows, caching, offline support, and error handling.

Preferred

• Experience integrating with ERP platforms via API (any major ERP: SAP, Oracle, Microsoft Dynamics, or open-source equivalents).
• Familiarity with cloud data lake or lakehouse architecture (Delta Lake, Databricks, or equivalent); pipeline development experience.
• OpenTelemetry instrumentation and APM platform integration.
• Infrastructure-as-code (Terraform, Pulumi, or equivalent).
• Experience with PCI-DSS considerations in payment integration contexts.
• African market deployment experience: low-bandwidth optimisation, USSD/mobile-money integration patterns, and in-country compliance requirements.
• Familiarity with fiscal e-invoicing requirements and tax system integrations.

• Bachelor's degree in Computer Science, Software Engineering, or a related technical discipline.
• Relevant cloud certifications (AWS, Azure) advantageous.
• Portfolio of shipped production projects demonstrating full-stack capability required.