[Job -32700] Senior C#/.NET Developer, Market Data Platform, Brazil at CI&T

About this role

At CI&T, we help large enterprises transform the potential of AI into real business impact with AI Deployment, AI-native execution, and tech-integrated business solutions. With 30 years of experience in technological transformation, we accelerate innovation with expertise in Agentic SDLC, Application modernization, Data & AI, Martech and Business strategy. We are 8,000 CI&Ters across more than 25 countries, collaborating to build solutions with real impact. AI is already part of how we work, evolve, and innovate every day.
Build the .NET client for the new services from gRPC .proto contracts. Re-implement the existing .NET wrapper so its public interface stays the same while calls go to gRPC and Arrow Flight instead of OneTick. Convert Arrow record batches into the .NET types applications use today, efficiently and without precision loss. Write tests that compare results from the old and new backends for the same calls.
Required 6+ years of C# and modern .NET (6 or later). Production experience with gRPC in .NET (Grpc.Net.Client, protobuf code generation, streaming calls). Hands-on use of Apache Arrow in .NET (Apache.Arrow package) or another columnar data format. Strong handling of high-volume data: memory allocation, Span/Memory, streaming, async. Care with timestamp precision, time zones and numeric types.
Nice to have
Arrow Flight in any language.
kdb+ C# client experience (csharpkdb, qSharp) or basic q. Prior work wrapping a market data or tick database API (OneTick, kdb+, Bloomberg, Refinitiv).
Background and ways of working
Finance background (preferred, not required) Market data work at a hedge fund, bank, broker or trading technology vendor. Familiarity with trades, quotes, order books, symbology, corporate actions and exchange calendars. Understanding of the difference between exchange, vendor and capture timestamps, and why it matters. Any of: equities, options, futures, FX or fixed income data.
Also expected Fluent written and spoken English ; comfortable working directly with client engineers. Writes tests and works in Git-based code review. Linux comfort; CI/CD and containers are a plus. Able to overlap at least 4 hours a day with US Eastern time.
Our benefits:
Health and dental insurance
Meal and food allowance
Childcare assistance
Extended paternity leave
Partnership with gyms and health and wellness professionals via Wellhub (Gympass) TotalPass;
Profit Sharing and Results Participation (PLR);
Life insurance
Continuous learning platform (CI&T University);
Discount club
Free online platform dedicated to physical, mental, and overall well-being
Pregnancy and responsible parenting course
Partnerships with online learning platforms
Language learning platform
And many more! More details about our benefits here: At CI&T, inclusion starts at the first contact. If you are a person with a disability, it is important to present your assessment during the selection process. See which data needs to be included in the report by clicking here .This way, we can ensure the support and accommodations that you deserve. If you do not yet have the assessment, don't worry: we can support you in obtaining it.
We have a dedicated Health and Well-being team, inclusion specialists, and affinity groups who will be with you at every stage. Count on us to make this journey side by side. Originally posted on Himalayas