Senior Full Stack Net Developer Jobs in Swansea, IL

About the Role

Grimco Inc. is a national sign supply distributor and manufacturer with operations across the U.S., Canada, and the United Kingdom. Our CRM and B2B webstore (Grimco.com) are core to how the business sells and operates - and both are under active investment, from modernizing legacy functionality to piloting AI and agentic features. We're looking for a senior developer to join the team that builds and maintains these platforms, works closely with our ERP and external partners on integrations, and helps set technical direction as we grow.

What You'll Do

Build and maintain features across our CRM and Grimco.com (B2B webstore), spanning front end, back end, and database layers.

Design and implement integrations between the CRM, the webstore, our ERP, and external partners via APIs, data pipelines, and file-based exchanges.

Apply modern development practices (clean code, modular design, SQL-first data access, automated and structured testing) across both platforms.

Evaluate and prototype opportunities to embed AI and agentic workflows into CRM and webstore features.

Serve as a technical resource on complex, cross-team projects, contributing to architecture and design decisions and seeing work through to production.

Identify and act on opportunities to modernize existing CRM and webstore functionality, including legacy areas of the codebase.

Collaborate closely with IT leadership, product/project management, QA, and business stakeholders (sales, marketing, customer service) to deliver well-scoped, well-documented solutions on a predictable cadence.

Participate in code reviews, mentor other engineers, and help raise the engineering bar across the team.

What You Bring

7+ years of professional full-stack software development experience, including production e-commerce, CRM, or similar customer-facing/B2B applications - senior-level tenure, not just senior-level title.

Strong front-to-back skills: React on the front end, C# / .NET on the API side, with solid RESTful API design chops.

Strong SQL and relational database skills - efficient queries, sound data modeling, and comfort optimizing for scale.

Demonstrated experience building integrations between systems: APIs, file-based exchanges, ERP connectivity, or similar.

Practical experience with AI-assisted development and/or building AI or agentic features into production applications - not just personal experimentation.

Comfortable working with legacy code you didn't write: reading, understanding, and improving it with confidence.

Clear communication skills; able to explain technical tradeoffs to non-technical stakeholders without losing the important detail.

Security awareness baked into how you work (authentication, data handling, PCI-adjacent considerations for e-commerce), not treated as an afterthought.

Preferred Experience

Background in distribution, wholesale, manufacturing, or B2B order management systems.

Experience with CRM platforms (custom-built or mid-market) and/or e-commerce platforms handling catalog, pricing, and checkout complexity.

Experience with ERP integration patterns, EDI/X12 transaction sets, or trading-partner data exchange.

Cloud integration experience (Azure, AWS, or similar) and familiarity with CI/CD pipelines.

Hands-on experience with agentic AI frameworks or tooling, or building on top of LLM APIs.

Mobile app development experience (native or cross-platform) relevant to a companion e-commerce app.

What We Bring: 

Full medical, dental, and vision benefits available. Medical premiums have remained unchanged for more than 18 years.

Paid Maternity/Paternity Leave

Paid Holidays

Paid Time Off Accrual (Paid Time Off payout available)

401K with Prot Sharing, up to 6% of the employee's total compensation earnings. 

Eligible for Employee Recognition Prizes

Employee Referral Benets

Volunteer Time Off   

Why Grimco?

A platform with real depth - CRM, webstore, and ERP integration work that touches the whole business.

Small, focused team where your work ships and your impact is visible.

Senior role with room to influence architecture and technical direction across the CRM and Grimco.com.

Stable, 150+ year company actively investing in modernizing its technology, including AI.

ABOUT GRIMCO:

Grimco is a national wholesale sign supply manufacturer and distributor with over 50 locations across North America. We focus on distributing quality products and providing excellent service to the sign industry. Our offering of sign supplies includes trafc signs, blanks, substrates, boards, digital print media, wrap lms, sign vinyl, application tape, banner material and supplies, sign frames, banner stands, LEDs and electrical accessories, grand format solvent/UV/latex printers, inks, software and more.

By completing this online application for employment, you certify that the information on this application is true and complete to the best of your knowledge. You understand that any misrepresentation or omission of fact in response to any inquiry made in this application may result in rejection of application or, if hired, dismissal whenever it is discovered. You authorize and release all parties from any liability or damage that may result from seeking, furnishing, or using such information. You understand and agree that, if hired, your employment is for no denite period and may, regardless of the date of payment of compensation, be terminated by Grimco, Inc. at any time, for any or no reason, with or without notice. You understand that no representation to the contrary is valid unless in writing, set a denite term of employment, and signed by the company's CEO. You further understand and agree that any job offer is contingent upon your passing, to the company's satisfaction, a drug and/or alcohol test, criminal background check and other possible screenings. You understand that this application is active for 90 days only, and if you do not hear from the company but still wish to be considered for employment after 90 days, you will need to ll out a new application.