movindo

Senior Software Developer — Backend, Mobile, Payments, Microcontrollers (Go, Java/Kotlin, Python, JavaScript)

I am a Senior Software Developer specializing in backend systems, Android mobile apps, payment gateway integration, and embedded/IoT with Arduino and microcontrollers. I design, build, and ship secure, scalable software end-to-end—from architecture and APIs to deployment and monitoring.

WHAT I DO
- Backend & APIs: microservices, REST/gRPC, authentication and RBAC, rate limiting, caching, async jobs, webhooks, and real-time features.
- Mobile (Android): native apps in Java/Kotlin, modular architecture (MVVM/Clean), offline-first sync, in-app purchases/subscriptions.
- Payments: end-to-end integrations (cards, e-wallets, bank transfers), tokenization, 3-D Secure, subscription billing, refunds, reconciliation, fraud checks, and PCI-aware flows.
- IoT & Microcontrollers: Arduino, RS-232/serial protocols, sensor and actuator control, device telemetry, gateway services, and field integrations.

TECH STACK
- Languages: Golang, Java/Kotlin, Python, JavaScript (Node.js)
- Frameworks: Gin/Fiber (Go), Spring (Java), FastAPI/Flask (Python), Express/Nest (Node)
- Data & Infra: PostgreSQL/MySQL, Redis, RabbitMQ/Kafka, Docker, CI/CD, Linux, basic cloud (AWS/GCP)
- Quality: unit/integration tests, load testing, observability (metrics, logs, traces), secure coding

HOW I WORK
- Architecture first: clear specs, domain modeling, and pragmatic microservices only when they add value.
- Security by design: secrets management, least privilege, input validation, and hardened endpoints.
- Performance and reliability: profiling, indexing, caching, back pressure; SLO/SLA mindset.
- Maintainability: clean code, documentation, and smooth handover.

SAMPLE OUTCOMES
- Built a payment orchestration layer (Go + PostgreSQL + Redis) with webhooks and retries; reduced payment failures and simplified adding new PSPs.
- Delivered an Android app (Kotlin + offline-first sync) for field operations; cut data entry time and improved reliability in low-signal areas.
- Implemented an IoT gateway (Python/Go) bridging RS-232 devices to cloud APIs; enabled real-time telemetry and remote diagnostics.
- Migrated a monolith to microservices with a staged rollout; faster deployments, lower blast radius, and clearer ownership.

SERVICES
- Backend/API development and refactoring
- Android app development and SDK/in-app payments
- Payment gateway integration and reconciliation
- IoT/Arduino prototyping and device-to-cloud integration
- Performance audits, security hardening, and cost optimization

If you need a developer who can move from device to cloud, from API to Android, and from prototype to production, let’s talk. I can review your requirements, suggest an approach, and provide a clear delivery plan with milestones.