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Posted 2 months ago

Senior Web Developer

@ Flexstaf IT

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Toronto, Ontario

Full-time5+ years experience
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SIGNALS

Overview

Flexstaf IT is hiring a Senior Web Services and Application Developer for a full-time role. The work covers maintaining and modernizing legacy web applications, REST and SOAP services, and complex SQL Server database workflows. The posting requires 5+ years of professional C#, ASP.NET, web services and SQL Server experience.

Responsibilities:

  • Build and maintain Web API, REST and SOAP services and ASP.NET applications
  • Develop and consume RESTful APIs and SOAP/WCF services for system integration
  • Write and optimize T-SQL queries, stored procedures, triggers and views
  • Refactor C# code and database scripts for performance, scalability and security
  • Support integration testing, resolve production issues and document architecture

Requirements summary:

  • 5+ years of professional C#, ASP.NET, web services and SQL Server experience
  • Deep proficiency in C#, ASP.NET, Web API, WCF/ASMX and front-end basics
  • Hands-on design and security of RESTful JSON and SOAP XML endpoints
  • Advanced T-SQL, execution plans and database indexing skills
  • Experience with Git, Azure DevOps or Team Foundation Server

Tools & skills

SQL ServerGitAzure DevOpsTeam Foundation ServerIISAzure Web AppsAzure API ManagementAzure SQL
Source and dates

Source type not verified · manatal

Employer posting date
2026-08-27
First seen by our source
2026-10-10
Source record updated
2026-11-05

These dates describe the source record, not a live verification that the employer is still hiring. Check the original posting.

Job details

SenioritySenior
DepartmentSoftware development
Experience5+ years
Hours per week40 (estimated)
Travelair: none · ground: none
Work settingOffice
PositionMostly sitting
Physical demandsphysical low · computer high
LanguagesEnglish

Summary and details written by AI from the posting; the employer’s posting is the authority.

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Flexstaf IT

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Job description

We are seeking an experienced Web Services & Application Developer with strong C#, ASP.NET, and SQL Server capabilities to maintain, modernize, and enhance legacy web applications, REST services, and SOAP web services. In this role, you will bridge the gap between web application maintenance and backend service integration, ensuring system stability, building secure APIs, and optimizing complex database workflows.

Key Responsibilities

  • Application & API Development: Design, build, and maintain Web API services, REST Services, SOAP web services, and existing ASP.NET applications using C#, .NET Framework, HTML5, CSS3, JavaScript, and AJAX.
  • Service Integration & Modernization: Develop and consume RESTful APIs and SOAP/WCF web services to enable seamless integration across enterprise platforms and legacy architectures.
  • Backend Data Engineering: Write complex SQL queries, stored procedures, user-defined functions, triggers, and views in T-SQL, optimizing database performance and data exchange workflows.
  • Legacy Refactoring & Security: Identify performance bottlenecks in web applications and web services; refactor and optimize C# code and database scripts for performance, scalability, and security (e.g., OWASP compliance, SQL injection prevention).
  • System Support & Integration: Support system integration testing, debug web service communication, resolve production issues, and document technical architecture and API endpoints.

Required Qualifications

  • Experience: 5+ years of professional software development experience with C#, ASP.NET, Web Services, and Microsoft SQL Server.
  • Core Tech Stack: Deep proficiency in C#, ASP.NET, REST Services (Web API), and SOAP Services (WCF / ASMX), alongside front-end fundamentals (JavaScript, jQuery, HTML5, CSS3).
  • Web Services & API Design: Strong hands-on experience designing, consuming, and securing RESTful JSON endpoints and XML-based SOAP contracts (WSDL, XSD, SOAP envelopes).
  • T-SQL Mastery: Advanced skills in writing and optimizing complex T-SQL queries, stored procedures, execution plans, and database indexing to support service payloads.
  • Version Control: Experience with Git, Azure DevOps, or Team Foundation Server (TFS).

Preferred Qualifications

  • Experience migrating legacy ASP.NET applications and SOAP services to modern frameworks (ASP.NET Core, RESTful microservices, Angular, or React).
  • Deep understanding of IIS server configuration, SSL/TLS certificates, and API security authentication models (OAuth 2.0, JWT, API Keys, Basic Auth).
  • Knowledge of cloud platforms (Azure Web Apps, Azure API Management, Azure SQL) or C# unit testing frameworks (xUnit, NUnit, Moq).

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