Building scalable systems,
AI-powered products.
I'm Wesley Leandro, a Senior Software Engineer with 7+ years building high-performance platforms in fintech and SaaS. I focus on system design, product engineering, and shipping software that scales — from architecture decisions to production.
Fintech · SaaS · Platform Engineering
Engineering Impact
Impact at scale
Current Focus
What I'm exploring
Areas I'm actively exploring and applying in production work.
AI Engineering
Integrating LLMs and AI workflows into product experiences with reliability and cost awareness.
Distributed Systems
Designing services and data flows that scale horizontally and fail gracefully.
Product Engineering
Translating ambiguous requirements into shippable, measurable product outcomes.
Scalable SaaS
Multi-tenant patterns, performance at scale, and infrastructure that grows with the business.
System Design
Architecture trade-offs, boundaries, and long-term maintainability.
Developer Experience
Tooling, CI/CD, and patterns that multiply team velocity.
About
Engineering with ownership
I'm a Senior Software Engineer based in Brazil, working remotely with global teams on products where reliability, performance, and scale are non-negotiable.
Over 7+ years, I've built platforms in fintech and SaaS — from secure transaction systems to investment platforms serving millions of users. My work sits at the intersection of system design, product engineering, and modern web architecture.
I care deeply about the decisions that compound: how teams structure code, how systems handle growth, how products ship without sacrificing quality. I'm as comfortable discussing API boundaries and deployment strategy as I am optimizing critical user flows.
Currently, I'm focused on AI-native product development, scalable SaaS architecture, and engineering practices that help teams move fast without breaking things.
Open to senior, staff, and founding engineer roles where technical ownership and product impact matter.
Engineering Capabilities
Technical breadth
Frontend Engineering
High-performance UIs, SSR/SSG, design systems
Backend & APIs
Service design, data modeling, API contracts
Cloud & Infrastructure
Deploy pipelines, containerization, cloud-native patterns
AI & Automation
Production AI features, engineering productivity
Developer Tooling
Testing, collaboration, design-dev alignment
Engineering Insights
Writing & ideas
Thoughts on architecture, scalability, and building modern products.
Experience
Work history
Penzack
2024 - PresentSenior Software Engineer
Own high-impact features for a global investment platform serving 2M+ users. Drive performance optimization, architectural patterns, and secure delivery in a regulated fintech environment.
Elint Tech
2022 - 2024Software Engineer
Led Next.js migrations for large-scale enterprise platforms. Built data visualization systems for major clients including Lacta and Universal Music.
Desencoder
2018 - 2022Full Stack Engineer
Designed and shipped scalable fintech applications with secure transaction flows, serving thousands of daily users. Full ownership from API design to production deployment.