Software Engineering Leader.
Hands-on Architect.

I combine 20+ years of hands-on software engineering with technical leadership experience, helping teams build reliable backend platforms, scalable cloud systems and practical AI-enabled products.

Former Technical Manager at ReferWell. Founding Technical Lead with CTO-level responsibilities at Qhali. Currently a hands-on Backend Software Engineer at ACIN.

Portrait of Oscar Caldeira

Selected Credentials

Top 10% AI Coder
Top 10% AI Coder
IBM AI Product Manager
IBM AI Product Manager
IBM AI Developer
IBM AI Developer
MongoDB – Building AI Agents
MongoDB – Building RAG Applications
Google – Prompt Design in Vertex AI

What I Bring to Engineering Teams

I operate comfortably between architecture, implementation and team leadership. My experience spans production-critical backend platforms, regulated healthcare systems, cloud delivery, technical modernization and AI-enabled product development.

Hands-on Technical Leadership

I remain close to architecture, critical implementation decisions, code reviews and production issues while helping engineers take ownership of delivery.

Backend Architecture & Modernization

Experience designing APIs, integrations, background processing and data workflows, as well as modernizing complex legacy platforms without disrupting business operations.

Engineering Team Development

Previous experience leading multidisciplinary and distributed teams, improving delivery practices, mentoring engineers and coordinating technical work with business stakeholders.

AI, Cloud & Interoperability

Practical experience with AI-enabled products, cloud infrastructure, CI/CD, healthcare interoperability and secure data platforms.

About

Leadership Experience.
Hands-on Engineering.

I started my career as a software developer and gradually moved into technical leadership, architecture and team management roles.

At ReferWell, I worked as a Technical Manager, coordinating engineering delivery and healthcare integrations in a regulated environment. At Qhali, I was a founding member and Technical Lead with responsibilities comparable to those of a CTO, covering architecture, team organization, cloud delivery and product development.

Qhali was later discontinued for business reasons. At the same time, I relocated with my family to Madeira and joined ACIN in a hands-on backend engineering role. This allowed me to establish myself in the Portuguese technology market while staying close to production systems, complex legacy modernization and day-to-day software delivery.

I am now looking to combine both sides of my experience: technical depth and engineering leadership.

I also explore independent product ideas and small software initiatives through Cre4tiva.

Based in Madeira, Portugal
20+ Years · Software Engineering Experience
Technical Manager · Leadership Experience
Hands-on

Backend & Architecture

Production systems, APIs, integrations, background processing, cloud delivery and modernization.

Leadership

Technical Management Experience

Team coordination, mentoring, delivery planning and stakeholder communication across distributed environments.

Leadership & Engineering Scope

Technical scope developed across hands-on engineering, architecture and team leadership roles.

Software Architecture

Backend services, platform integration, API design, distributed workflows, data platforms and modernization strategies for production systems.

Technical Management

Team coordination, delivery planning, technical mentoring, stakeholder communication, engineering standards and risk management.

Cloud, DevOps & Reliability

AWS and Azure environments, Docker, CI/CD pipelines, observability, incident analysis and deployment automation.

AI-Enabled Products

LLM integrations, RAG architectures, AI agents, vector databases and practical applications of generative AI in software products.

Selected Experience

Engineering & Leadership Experience

More than 20 years progressing from software development into architecture, technical management and hands-on backend engineering.

2025–Present

Backend Software Engineer

ACIN / iParque · Madeira, Portugal

Working hands-on on backend systems for mobility and municipal operations. My responsibilities include legacy modernization, API development, background processing, permission systems, production issue analysis and improvements to automated testing and deployment reliability.

PHPREST APIsMySQLDockerCI/CDLegacy Modernization
2024–2025

Founding Member & Technical Lead

Qhali · Remote

Held technical leadership responsibilities comparable to those of a CTO for an AI-enabled healthcare platform. Defined architecture and technical requirements, coordinated a multidisciplinary engineering and AI team, and established cloud and delivery practices from product conception through deployment.

AzurePythonLLMsVector DatabasesCI/CDTechnical Leadership
2022–2024

Technical Manager

Zeal Tech / ReferWell · Remote

Led technical delivery and healthcare integration initiatives for a US HealthTech platform. Coordinated engineers and external stakeholders, supported HIPAA and HITRUST compliance efforts, and implemented interoperability with healthcare providers using FHIR, HL7 and REST APIs.

FHIRHL7HIPAAHITRUSTAWSTechnical Management
2016–2021

Full-Stack Developer & Technical Lead

E-Managing Solutions · Remote

Designed and delivered CRM and workflow platforms for real estate and financial-sector clients. Led technical implementation, integrations and distributed delivery across multiple client products.

Node.jsPHPReactTwilioAPI IntegrationsTeam Leadership
2005–2016

Software Developer & Technical Lead

Webconsult / XCS Professional Services · Venezuela

Built and led the delivery of business platforms across industrial, event-management, education and administrative domains, progressing from full-stack development into technical leadership.

PHPJavaScriptSQLWeb PlatformsTechnical Leadership

Selected Case Studies

Most of my professional work belongs to private platforms. These summaries focus on the problems, responsibilities and engineering decisions without exposing confidential code or customer data.

ReferWell

HealthTech Integration Platform

Role: Technical Manager

Context

A regulated US healthcare platform requiring reliable integrations with multiple providers and interoperability systems.

Contributions

  • Coordinated engineering delivery across integration initiatives.
  • Worked with FHIR, HL7 and third-party healthcare APIs.
  • Supported HIPAA and HITRUST compliance requirements.
  • Collaborated with internal teams, vendors and business stakeholders.

Qualitative result

Improved reliability and visibility across critical integration workflows.

AWS, FHIR, HL7, REST APIs, Datadog, SQL

Qhali

AI-Enabled Healthcare Platform

Role: Founding Member & Technical Lead

Context

A new healthcare product combining patient information, AI-assisted workflows and secure cloud services.

Contributions

  • Helped define the platform from concept to deployment.
  • Designed backend and AI integration architecture.
  • Coordinated engineers and AI specialists.
  • Established Azure-based CI/CD and delivery practices.

Qualitative result

Implemented LLM and vector-search workflows for medical information use cases.

Azure, Python, LLMs, Vector Databases, Docker, CI/CD

ACIN / iParque

Legacy Platform Modernization

Role: Backend Software Engineer

Context

A long-running production platform requiring continuous feature delivery while modernizing legacy components.

Contributions

  • Modernized backend code for current PHP versions.
  • Implemented and maintained APIs, jobs and business workflows.
  • Diagnosed production problems and compatibility regressions.
  • Improved automated tests and deployment safety.

Qualitative result

Supported safer ongoing delivery within a mature product and engineering environment.

PHP, MySQL, REST APIs, Docker, CI/CD, Automated Testing

Technical Capabilities

Technologies and domains I have used across production systems, technical leadership roles and independent product development.

Backend & Architecture

PHPLaravelNode.jsTypeScriptPythonFastAPIREST APIsDistributed WorkflowsLegacy Modernization

Data & Interoperability

PostgreSQLMySQLMongoDBElasticsearchFHIRHL7Vector Databases

Cloud & Delivery

AWSMicrosoft AzureDockerCI/CDGitHub ActionsAzure DevOpsDatadogSentry

Applied AI

OpenAIAnthropic ClaudeGoogle GeminiRAGAI AgentsLangGraphPrompt EngineeringLLM Evaluation

Secondary frontend experience includes React and responsive web interfaces.

Let's Build Reliable Software

I am open to selected Principal Engineer, Software Architecture and Engineering Leadership opportunities, particularly where hands-on technical depth and team leadership are equally important.