Signal 01
50+
Financial products supported by BTG Pactual's Balance Online platform
Senior Software Engineer · Brazil
I build the backend systemsfinancial products depend on.
Gabriel Reis engineers distributed Java platforms for regulated, high-stakes environments—turning architectural complexity into reliable software, measurable performance, and production confidence.
01
Domain design
02
Distributed flows
03
Production reliability
Production topologyLive thinking
API boundaryDomain coreEvent streamTelemetry
GR / 01
Current environmentTrading systems · BTG Pactual
Java 8—21Spring BootEvent-drivenDDDAWSObservabilityKubernetes
01Production impact
Architecture earns trust through outcomes.
Selected signals from financial platforms, distributed onboarding, messaging infrastructure, and backend modernization.
Signal 02
92.5%
Endpoint performance improvement, from 8s to 600ms
Signal 03
60%
Messaging cost reduction through SNS/SQS consolidation
Broader delivery footprint
Years of software engineering experience
Services supported in distributed onboarding ecosystems
Features delivered for a No-Code ERP/Web framework
02Selected systems
Real constraints. Explicit decisions. Observable impact.
Four engineering stories that show how Gabriel frames the problem, chooses a system direction, and stays accountable for production consequences.
CASE01
Technical ownership inside BTG Pactual's critical financial platform
Balance Online Platform Ownership
Technical ownership · 50+ products
- Constraint
- Balance Online supports more than 50 financial products, requiring accuracy, consistency, traceability, resilience, and production reliability across regulated workflows.
- System decision
- As technical owner of strategic initiatives, Gabriel leads architecture decisions, technical planning, solution design, and delivery execution across distributed services, APIs, reconciliation flows, and cross-platform integrations.
- Production result
- Drives the platform's architectural evolution through DDD, Hexagonal Architecture, event-driven patterns, and cloud-native practices while translating complex financial requirements into maintainable technical solutions.
CASE02
Financial-grade backend systems for regulated environments
PIX Compliance Microservices
Regulatory fit · traceable services
- Constraint
- Banco PAN needed backend services aligned with PIX and Bacen requirements, where traceability, correctness, and regulatory fit were central constraints.
- System decision
- Gabriel helped deliver five financial microservices using reactive Spring Boot practices, with attention to service boundaries, integration behavior, and production reliability.
- Production result
- The work supported PIX compliance initiatives in a regulated banking environment.
CASE03
From BFF complexity to clear business boundaries
Modular Monolith Refactoring for Bradesco
Clearer ownership · fewer conflicts
- Constraint
- The BFF layer had accumulated broad responsibilities, making business rules harder to isolate and increasing the cost of change.
- System decision
- Gabriel led a refactoring toward a modular monolith using DDD and Hexagonal Architecture, establishing bounded contexts and documenting the direction through an ADR.
- Production result
- The refactor improved maintainability, reduced merge conflicts, and made ownership of business behavior easier to reason about.
CASE04
Consolidating SQS queues with SNS/SQS architecture
Event-Driven Messaging Cost Optimization
60% lower messaging cost
- Constraint
- Three isolated SQS queues created unnecessary operational cost and fragmentation in an event-driven flow.
- System decision
- Gabriel consolidated the messaging flow into a unified service using AWS SNS and SQS, keeping the design aligned with asynchronous processing needs.
- Production result
- The change reduced operational messaging costs by 60%.
03Operating history
From product delivery to architectural ownership.
A career built across banking, public-sector platforms, enterprise modernization, and tooling—progressively closer to the decisions that determine reliability.
Senior Software Engineer
Technical owner of strategic initiatives within BTG Pactual’s Balance Online platform, a critical financial system supporting more than 50 financial products.
- Leading architecture decisions, technical planning, solution design, and delivery execution across highly regulated financial workflows.
- Designing and implementing distributed backend services and APIs for financial processing, reconciliation, and cross-platform integrations.
- Partnering directly with business stakeholders to translate complex financial requirements into scalable and maintainable technical solutions.
- Operating in a mission-critical environment where calculation accuracy, consistency, traceability, resilience, and production reliability are essential.
- Driving architectural evolution through Domain-Driven Design (DDD), Hexagonal Architecture, event-driven patterns, and cloud-native practices.
Senior Software Engineer
Led the architectural refactoring of Bradesco's BFF layer into a modular monolith using Hexagonal Architecture and DDD.
- Established bounded contexts and helped isolate business rules from API gateway responsibilities.
- Authored an ADR to formalize architectural decisions and guide team adoption.
- Reduced production bugs and merge conflicts by decomposing god classes into well-defined business contexts.
- Delivered 5 financial microservices supporting PIX compliance for Banco PAN using reactive Spring Boot and Bacen-compliant practices.
- Co-developed a native Java workflow engine for Bradesco, enabling BPMN-like programmatic workflow definition.
- Consolidated 3 isolated SQS queues into a unified SNS + SQS architecture, reducing operational messaging costs by 60%.
Mid-level Developer
Engineered and optimized microservices for Cresol's account onboarding ecosystem with 14+ services.
- Used Java, Spring Boot, RabbitMQ, and Camunda across critical backend flows.
- Modernized a mission-critical onboarding flow using BPMN and Camunda.
- Improved a key endpoint by 92.5%, reducing response time from 8s to 600ms.
- Worked closely with architecture, product, QA, and business teams.
Mid-level Developer
Designed and built a modern legal reporting system for FAPESB using Java 17, Spring Boot, and Tomcat 10.
- Replaced a legacy solution with a robust backend platform.
- Improved traceability, compliance, and performance for public-sector processes.
- Added observability using Prometheus and Grafana.
- Migrated legacy monolith features to REST-based microservices.
- Improved system efficiency by 25% and reduced response time by 15%.
Software Engineer
Improved the Maker No-Code framework for ERP and web application development.
- Delivered 40+ features across framework, backend, and dynamic UI capabilities.
- Used Java Reflection and multithreading to improve dynamic behavior execution.
- Built dynamic HTML grid generation from datasets.
- Built a smart Excel upload tool that auto-generated HTML forms and database tables.
04Architecture stance
A system is only well designed if it stays understandable under pressure.
Gabriel’s approach connects domain boundaries to runtime behavior: decisions are documented, failure paths are owned, and critical flows remain visible in production.
ENTRYAPI boundaryvalidate · route
OWNERSHIPDomain corerules · invariants
FLOWEvent backbonepublish · consume
Observability planetrace · measure · explain
Owned boundarySystem dependencyAsynchronous path
Domain boundaries before technical layers
Architecture starts by making the business language explicit, then protecting it with clear module ownership.
Reliability as a product requirement
Resilience, traceability, and failure handling belong in the product conversation from the beginning.
Event-driven design with operational responsibility
Asynchronous systems need ownership, observability, retries, and cost awareness, not only message brokers.
Performance and observability from day one
Critical paths should be measurable, tunable, and explainable before they become production incidents.
05Capability matrix
Tools are selected by the problem they need to solve.
A production-tested toolkit organized around engineering responsibilities—not a keyword inventory.
01
Core implementation
Backend
Java 8-21Spring BootQuarkusREST APIsMicroservicesServletsJSP
02
System direction
Architecture
Distributed SystemsEvent-Driven ArchitectureDDDHexagonal ArchitectureClean ArchitectureCQRSModular MonolithsSystem Design
03
Distributed transport
Messaging
KafkaRabbitMQAWS SNSAWS SQS
04
Runtime platform
Cloud & DevOps
AWSAzureGoogle CloudDockerKubernetesCI/CDVercel for this site
05
Production feedback
Observability
PrometheusGrafanaDistributed TracingPerformance Tuning
06
Data foundation
Databases
PostgreSQLRelational DatabasesDatabase modelingQuery optimization
07
Engineering discipline
Practices
TDDADRsClean CodePerformance OptimizationProduction Reliability
Communication bandwidth
PortugueseNativeEnglishC1 - AdvancedSpanishB2 - Upper Intermediate
Available for the right conversation
Building something that has to work when it matters?
Let’s talk about senior backend roles, financial platforms, architecture modernization, or the reliability problem keeping your team awake.