Okada Systems is a software engineering and cloud consultancy based in Brazil. I build applications in C# and .NET, with a background in financial markets systems, and run them on AWS with Terraform. I work with Spec-Driven Development to ship fast without losing track of what was built.
## Real-time quotes
- GET /quotes/{pair}: bid, ask, spread
- p99 under 50 ms
- Authenticated clients onlyapp.MapGet("/quotes/{pair}",
async (string pair, IQuoteService svc) =>
await svc.GetAsync(pair) is { } q
? Results.Ok(q)
: Results.NotFound())
.RequireAuthorization();resource "aws_ecs_service" "quotes" {
name = "quotes-api"
cluster = aws_ecs_cluster.main.id
launch_type = "FARGATE"
desired_count = 2
# task definition and networking omitted
}I work with Spec-Driven Development. Before any code is written, we agree in writing on what the system must do. Once the specification is approved, implementation moves quickly with AI agents, and every acceptance criterion becomes an automated test.
Requirements, API contracts and acceptance criteria written and approved with you.
The spec turns into a technical design and small tasks, each traced back to a requirement.
C#, Python or Terraform generated from the spec, with my review at every step.
Acceptance criteria run as tests in the pipeline, which only deploys to AWS what passes.
Why it's faster: ambiguity gets resolved on paper, where a change costs minutes, not after deployment, where it costs weeks. And you get the specification along with the code, so the next team doesn't start from scratch.
Software and the infrastructure it runs on, as fixed-scope projects or ongoing support, always versioned in your own repository.
ASP.NET Core services with automated tests, ready to run in containers on AWS.
FX, derivatives and real-time pricing: Disruptor-pattern ring buffers, the FIX protocol, FpML, Bloomberg integrations and streaming quotes over WebSocket.
FastAPI services and Lambda functions when the team or the problem calls for that stack.
ECS Fargate, RDS, S3, Lambda and Step Functions, plus migrations between clouds or regions without stopping the business.
Modules, protected remote state and GitHub Actions pipelines with OIDC instead of static keys.
Least-privilege IAM, Cloudflare WAF, actions pinned by SHA and defenses against compromised packages.
Mandatory tagging, orphaned resources under control and audit trails aligned with Brazil's LGPD.
A typical design: an edge protected by Cloudflare, .NET APIs in containers with no servers to manage, and the whole environment provisioned by a pipeline with no long-lived access keys.
Nothing clicked together in the console. Everything reviewable in a pull request.
Low-latency applications for spot FX and derivatives at a financial institution, built on a Disruptor-pattern ring buffer, the FIX protocol, FpML and Bloomberg integrations, plus real-time rate pricing with spreads over WebSocket.
Disruptor, FIX, FpML, Bloomberg, WebSocket
Planned and executed the cloud move of a production platform: containers, databases and file storage, with operations running throughout.
AWS, ECS Fargate, RDS, S3, Terraform
During a wave of attacks on npm packages, I standardized install-script blocking, credential rotation and workflow reviews across every product team.
GitHub Actions, pnpm, npm
Side project built with Spec-Driven Development on Cloudflare Workers and D1: per-user keys derived with HKDF, AES-256-GCM field encryption, Google OIDC sign-in and data handling compliant with Brazil's LGPD.
Cloudflare Workers, D1, React
I'm Ravs, founder of Okada Systems. I started in IT support, built my career developing in C# and .NET, including for financial markets, and today lead infrastructure, security and DevOps.
Software engineering and cloud consultancy.
Leading cloud, security and DevOps for several product teams, including a full migration from GCP to AWS.
FX and derivatives systems, trade history platform, micro-frontends, BDD and real-time pricing.
International projects in C#, Angular, Ext JS, SQL Server, Db2 and Azure.
Networks, servers and help desk, where it all began.
C#, .NET and ASP.NET Core, SQL Server, Python, Node.js, React, AWS, Terraform, GitHub Actions, Cloudflare, Docker and MongoDB Atlas.
Remote engagements for companies in Brazil and abroad. One conversation is usually enough to understand the situation and tell you honestly whether we're a good fit.