Sr. / Lead .NET Developer

About the Role
We’re hiring a backend engineer to keep our .NET platform running well and to improve it over time. A large part of the platform runs on .NET Framework: Windows Services, on-premises SQL Server, and a lot of message-driven work. It has been in production for years, and it shows. There are memory leaks nobody has tracked down yet, endpoints that slow down under load, and bugs that only appear in production.
Fixing that is the job. You’ll also help move parts of the platform forward, so we want someone who knows modern .NET well and can tell the difference between code that’s old and code that’s actually broken.
What You’ll Do
Track down memory leaks, thread contention, connection pool problems, and slow queries in long-running services
Work production incidents using Datadog to find the root cause
Debug across process boundaries: queues, caches, background workers, and the database
Fix defects and add functionality to the existing codebase without breaking what already works
Design and tune caching, including invalidation strategies
Build and maintain message-based workflows in RabbitMQ and MSMQ
Write and optimize SQL Server queries, stored procedures, and indexes
Help plan and carry out an incremental migration off .NET Framework where it makes sense
Document design and architecture decisions
Write tests with real coverage on the code paths you touch
Collaborate with other engineering teams, product, and external partners
Required Qualifications
10+ years of backend development
Strong .NET Framework 4.x experience. This is the main codebase, not a side part of it
Strong .NET Core / .NET 8+ experience and knowledge of current patterns
Windows Services and background process development
Message queues (RabbitMQ, MSMQ, or similar), including retries, poison messages, and idempotency
Distributed and in-process caching, and the failure modes that come with them
SQL Server: complex queries, stored procedures, indexing, and reading execution plans
Hands-on debugging and profiling: memory dumps, dotMemory, dotTrace, PerfView, WinDbg, or similar
Experience supporting production systems with APM tooling
Strong design patterns and general design skills that aren’t tied to one language
REST and SOAP services, XML and JSON
Scrum or similar; Git, Jira, Confluence
Bachelor’s in Computer Science or equivalent experience
Preferred Qualifications
Azure, especially services that support a move off on-prem: App Services, Functions, Service Bus, Event Hub, Azure SQL
Cosmos DB or other NoSQL
Kafka
Multi-tenant SaaS architecture
Master’s degree
Technical Environment
.NET Framework 4.x · .NET Core / .NET 8+ · Windows Services · SQL Server (on-prem) · RabbitMQ · MSMQ · Datadog · REST / SOAP · XML / JSON · Git · Jira · Confluence · Nice to have: Azure · Cosmos DB · Kafka
Why Join Us
Real engineering problems where your debugging skills have visible impact
A hands-on role in modernizing a mature platform, from .NET Framework toward .NET 8+ and the cloud
Senior / Lead-level ownership and influence on architecture decisions
100% remote work from LATAM with Unosquare

Work arrangement
Yes