Senior .NET Developer

AVANTTi

. Develop features and enhancements in C#/.NET (.NET Framework, modern .NET, ASP.NET Core, Web API, and MVC).

Posted 11/4/2026full-timeRemote • BrazilSeniorWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates extensive experience in C#/.NET development, application security, and vulnerability remediation, with a strong focus on financial processing integrity and compliance. Proficient in implementing secure authentication mechanisms and integrating security practices into CI/CD pipelines.

Highest-signal resume keywords

C#/.NET DevelopmentApplication SecuritySQL Server OptimizationAPI SecurityCI/CD Integration

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

C#.NET Framework.NET CoreASP.NET CoreWeb APISQL ServerT-SQLStored ProceduresAutomated TestingVulnerability Remediation

Tools & Technologies

SonarQubeSnykIISWindows ServerOAuth 2.0OpenID ConnectJWTSASTDASTSecrets Management

Industry Keywords

Financial ProcessingOWASP Top 10SOLID PrinciplesClean ArchitectureAudit LogsNIST SSDFOWASP ASVS 5.0Data Security ControlsEncryptionTLS

Tech Stack

Tools & technologies

ASP.NETSQL.NET

About the role

Key responsibilities & impact

Develop features and enhancements in C#/.NET (.NET Framework, modern .NET, ASP.NET Core, Web API, and MVC).
Investigate and fix bugs, optimize SQL Server routines, and maintain legacy systems (IIS, Windows Server), ensuring the integrity of financial processing.
Identify, analyze, and mitigate code and architecture vulnerabilities, including OWASP Top 10, SQL Injection, XSS, CSRF, SSRF, and IDOR/BOLA.
Review and implement secure authentication and authorization mechanisms (OAuth 2.0, OpenID Connect, JWT, and integrated authentication).
Fix insecure SQL queries, protect sensitive data, and implement controls against unauthorized access and operation tampering.
Conduct security- and quality-focused code reviews.
Introduce automated security checks and vulnerable dependency management (SAST, DAST, SCA) into CI/CD pipelines using SonarQube and Snyk.
Write and maintain regression and automated tests.
Ensure transactional integrity, idempotency, traceability, and access segregation in financial processes.
Protect fund, portfolio, and position data while maintaining logs and audit trails as technical evidence for audits and regulatory compliance.

Requirements

What you’ll need

7–10 years of software development experience, including at least 5 years of solid experience with the C#/.NET ecosystem.
Hands-on, proven experience in application security and remediating code vulnerabilities.
Strong command of C# (.NET Framework, .NET Core, ASP.NET Core, Web API, and MVC).
Advanced knowledge of SQL Server (T-SQL, stored procedures, transactions, permissions, and performance tuning).
Experience with API security (OAuth 2.0, OpenID Connect, and JWT) and OWASP Top 10 concepts.
Knowledge of software architecture (SOLID, Clean Architecture, and API design) and automated testing.
Hands-on experience supporting and integrating applications in legacy environments (IIS and Windows Server).
Knowledge of integrating security into CI/CD pipelines, Git, and static analysis tools (SonarQube, Snyk, or equivalent tools).
Experience implementing data security controls (encryption, TLS, secrets management, and audit logs).
Relevant differentiators: knowledge of or experience with financial market business rules (investment funds, portfolios, positions, processing, and reconciliation).
Technical familiarity with the OWASP ASVS 5.0 guide and the NIST SSDF framework.