Senior Developer – CRM & E-Commerce – Full-Stack

Grimco, Inc.; Sunset Hills (MO); On-site; USD 120,000 - 160,000; Full time

Benefits offered by this job

Medical benefits

PTO

401K with Profit Sharing

Paid Holidays

Maternity/Paternity Leave

Job summary

Grimco Inc. is seeking a senior full-stack developer to own and evolve our CRM and B2B webstore, Grimco.com.

You will work across frontend, backend, and database layers, partnering with ERP and external partners on integrations while helping set technical direction as the company grows. You will apply modern development practices, prototype AI-enabled features, and mentor teammates, ensuring secure, scalable delivery.

Qualifications

• 7+ years of professional full-stack software development experience in e-commerce/CRM/B2B apps.
• Strong front-to-back skills: React on the frontend, C#/.NET on the API side, with REST API design chops.
• Experience building integrations between systems: APIs, ERP connectivity, or file-based exchanges.
• Practical experience with AI-assisted development and/or agentic features in production apps.
• Comfort with legacy code: reading, understanding, and improving it.
• Clear communication skills to explain tradeoffs to non-technical stakeholders.
• Security awareness in authentication, data handling, PCI-adjacent e-commerce considerations.

Responsibilities

• Build and maintain features across CRM and Grimco.com (B2B webstore).
• Design and implement integrations between CRM, webstore, ERP, and external partners via APIs, data pipelines, and file exchanges.
• Apply modern development practices (clean code, modular design, SQL-first data access, testing).
• Evaluate and prototype AI/agentic workflows in CRM and webstore features.
• Act as a technical resource on cross-team projects, contributing to architecture and design and delivering to production.
• Modernize existing CRM/webstore functionality, including legacy areas of codebase.
• Collaborate with IT leadership, product/project management, QA, and business stakeholders to deliver well-scoped solutions.
• Participate in code reviews, mentor engineers, and raise engineering bar.

Skills

Full-stack development

REST API design

AI integration

ERP integrations

Legacy code understanding

Security conscious

Effective communication

Tools

React

C#/.NET

SQL

APIs

Job description

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.

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.

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.

Job Description

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.

Qualifications

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.

Additional Information

What We Bring:

• Full medical, dental, and vision benefits available. Medical premiums have remained unchanged for more than 18 years, costing only $16.50/biweekly paycheck for employee only coverage.
• Paid Maternity/Paternity Leave
• Paid Holidays
• Paid Time Off Accrual (Paid Time Off payout available)
• 401K with Profit Sharing, up to 6% of the employee’s total compensation earnings.
• Eligible for Employee Recognition Prizes
• Employee Referral Benefits
• 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 traffic signs, blanks, substrates, boards, digital print media, wrap films, 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.