Senior Software Engineer

We are seeking a Senior Software Engineer to support, enhance, and modernize a Microsoft-based technology stack that serves multiple business teams and customers. This role requires a hands-on engineer who can work directly with stakeholders, understand business processes, translate needs into practical technical solutions, troubleshoot complex issues across both modern and legacy systems, and thoughtfully apply AI tools to improve development, analysis, documentation, and operational support, including a practical understanding of how modern AI/LLM-based solutions are structured and integrated into applications.

The ideal candidate is comfortable balancing new development with day-to-day production support, root-cause analysis, system improvements, clear communication with business partners, and a proven track record leveraging AI toolsets to improve software delivery, analysis, documentation, and operational efficiency.

Communication skills are critical to this position, and this person must be able to establish rapport and work through issues with business users when identifying solutions to business problems.

Core Development Responsibilities:

Design, develop, maintain, and support enterprise applications using modern .NET (.NET 9 and beyond)

Work directly with business users, customers, and stakeholders to understand requirements, clarify needs, and recommend practical solutions

Perform business analysis by documenting processes, identifying gaps, translating business requirements into technical specifications, and validating solutions with end users

Jump into existing and legacy .NET applications to troubleshoot production issues, analyze unfamiliar code, support integrations, and improve stability and maintainability

Debug complex application, data, integration, and configuration issues across legacy systems, APIs, SQL Server databases, scheduled jobs, and operational workflows

Work extensively with Microsoft SQL Server, including writing and optimizing SQL queries, views, stored procedures, and data fixes

Support and enhance existing database schemas, data integrations, reporting needs, and operational data flows

Build and maintain APIs and backend services that integrate internal and external systems

Develop, deploy, and support applications using Microsoft Azure development-related services, including Azure App Service and related cloud application services

Use AI-assisted development tools to accelerate research, code analysis, debugging, documentation, test planning, and solution design while maintaining sound engineering judgment

Work with AI/LLM APIs and services (e.g., Azure OpenAI or similar) to prototype and support lightweight AI-enabled features, integrations, or workflows

Understand and contribute to AI solution patterns such as prompt design, retrieval-augmented generation (RAG), and data grounding approaches, as applied to real business use cases

Evaluate practical AI use cases that can improve internal workflows, automate repetitive tasks, enhance knowledge retrieval, or support business users more effectively

Identify opportunities to modernize, refactor, and improve current solutions without disrupting business operations

Participate in technical discussions and help guide design and architectural decisions

Communicate clearly with engineers, business partners, customers, and stakeholders throughout discovery, development, testing, deployment, and support

Customer-Facing and Business Analysis Responsibilities:

Engage directly with internal customers and business stakeholders to understand operational needs, pain points, priorities, and success criteria

Lead or support requirements-gathering conversations, working sessions, demos, and follow-ups with business users

Translate business problems into clear user stories, acceptance criteria, technical tasks, and implementation plans

Analyze current-state workflows, legacy system behavior, data dependencies, and integration points to determine practical solution options

Help users validate fixes and enhancements through testing, walkthroughs, and clear communication of expected behavior

Provide production support by investigating reported issues, reproducing problems, reviewing logs and data, and explaining findings in business-friendly terms

Document system behavior, support procedures, known issues, and business rules to improve team knowledge and long-term maintainability

Apply AI-assisted tools and techniques to improve requirements analysis, summarize complex information, draft documentation, explore legacy code behavior, and identify opportunities for automation while keeping the primary focus on solving business and customer problems

Ideal Candidate Traits:

Customer-focused and comfortable working directly with business users and stakeholders

Strong communicator who can explain technical issues clearly to both technical and non-technical audiences

Strong analytical thinker who can ask good questions, uncover root causes, and connect business needs to technical solutions

Comfortable debugging unfamiliar legacy systems, tracing data flows, reading existing code, and learning how older applications work

Curious and pragmatic about AI, with a working understanding of how AI/LLM-powered systems function (prompts, APIs, grounding, data flows) and the ability to identify where they can improve productivity, analysis, support, or solution quality without overcomplicating the architecture

Willing to challenge assumptions, call out risks, and propose practical alternatives

Strong sense of ownership and a proactive, can-do attitude

Able to balance production support, business priorities, technical debt, and new development

Strong independent worker who is ready to jump in and start contributing on a small engineering team

Experience with modern Javascript UI frameworks (React, Angular, Vue) and ASP.Net.

Preferred:

Hands-on experience with AI-assisted development tools, prompt engineering, LLM-based workflows, RAG concepts, or practical AI pilots that support software delivery or business operations

Experience using AI tools to analyze legacy code, summarize technical documentation, accelerate troubleshooting, generate test scenarios, or improve developer productivity

Exposure to AI-enabled knowledge retrieval, document search, semantic search, embeddings, vector databases, or chatbot-style solutions for internal business users

Ability to evaluate where AI can responsibly improve business processes, support workflows, data analysis, documentation, or operational efficiency

Familiarity with integrating AI capabilities into applications, automation workflows, APIs, or internal tools while considering accuracy, security, usability, and maintainability

Experience working with AI/LLM APIs (e.g., Azure OpenAI, OpenAI, or similar) to prototype or integrate AI capabilities into applications, automation workflows, or internal tools

Typically, a mosaic is where all the pieces fit together nicely. That’s not us. This Mosaic is where every piece stands out. That’s because each person at our agency brings their own, unique set of skills to every brief, build, interaction, reaction, design and idea.

As part of the Acosta Group, Mosaic is one of the original marketing agencies who specialize in interactions, experience isn’t just what we have, it's what we create. With 3,000+ team members and hubs in Toronto and Dallas, we’ve spent over 35 years bringing brands to life through experiential marketing, integrated commerce campaigns, and field sales strategies that drive real behavior change.

From awareness, to earned, brand equity, consideration, and sales - we approach every project with people in mind, regardless of the channel or discipline. The result is an idea that can spark emotion and create action - whether it’s a sale or a smile. We celebrate bold thinking and embrace curiosity as we shape what’s next.

Acosta Group believes in good faith that the minimum and maximum annual salary or hourly compensation range for this opportunity is accurate and reasonable at the time of posting.

AI and Automated Decision-Making Notice

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