Technical Co-Founder / Founding Engineer

Technical Co-Founder / Founding Engineer at MainSquare Technical Co-Founder / Founding Engineer at MainSquare in Royal Palm Beach, Florida Posted in about 20 hours ago.

Type:

full-time

Job Description:

Company Description MainSquare is a value creation transformation system specializing in supporting middle market companies with $1M

• 10M EBITDA.

By bridging the gap between critical business needs and AI-driven operational solutions, MainSquare empowers clients to focus on strategy, capital allocation, and leadership. We operate as a structured value-creation layer, addressing operational independence, earnings quality, and systemization to enhance transferability and increase exit multiples. Positioned as a fractional Chief of Staff, we coordinate the execution of key tactical EBITDA drivers, delivering action-biased strategies that prioritize investment returns and measurable results. We are building a proprietary platform to operationalize this methodology. Client-facing engagement tools, internal data rooms, partner coordination, KPI dashboards, and governance workflows. The Technical Co-Founder will own that build. Role Description We are looking for a Technical Co-Founder / Founding Engineer who will own end-to-end platform development. From architecture and infrastructure decisions to front-end UX and backend data logic. This is not a vendor relationship or a contract engagement. This is a founding seat. You will work directly with the founder to translate the MainSquare methodology into software. You will make real technical decisions, move fast, and build something that matters while owning a meaningful stake in the outcome.

The standard:

If you need a project manager, a ticket system, and three rounds of approval to push to production, this is not your seat. If you thrive on ownership and move fast when the direction is clear, keep reading. Key Responsibilities Platform Architecture & Technical Leadership Own all technical decision-making: stack, architecture, data model, deployment, and tooling choices Lead end-to-end development across frontend, backend, database, and infrastructure Build for scale without over-engineering

• pragmatic choices at a pre-revenue startup matter Establish engineering standards, code quality practices, and documentation conventions from day one Shape the long-term technical roadmap in direct partnership with the founder Frontend Development Build modern, responsive, and performant web applications in React and TypeScript Design and implement intuitive user interfaces for complex operational workflows•client portals, dashboards, data rooms, reporting views Own UX decision-making•you do not need a designer to ship clean, functional product Continuously improve performance, accessibility, and user experience across the platform Backend Development Design and build backend services, REST APIs, and business logic in Node.

js Architect and maintain scalable, maintainable application structure as scope and complexity grow Build integrations with third-party tools as the platform ecosystem expands Ensure API reliability, error handling, and observability from the start Database Management Design, optimize, and maintain MongoDB architecture, schemas, and data flows Ensure data integrity, consistency, and reliability across the platform Build efficient query patterns and indexing strategies for operational workloads Own data migration, backup, and recovery practices Infrastructure & DevOps Manage deployments, hosting, scalability, and platform reliability

• likely on AWS or comparable cloud infrastructure Build and maintain CI/CD pipelines and deployment automation Monitor and optimize infrastructure costs
• we are a startup; efficiency matters Quickly evaluate and adopt new technologies when they genuinely improve the stack Security & Authentication Implement secure authentication and authorization systems
• sign-up/sign-in flows, role-based permissions, session management Apply security best practices across the full stack: input validation, encryption, secrets management, access controls Ensure compliance with data security standards relevant to client-facing business intelligence tooling Product & Co-Founder Responsibilities Collaborate directly with the founder on product vision, roadmap prioritization, and execution Contribute to product strategy•you will have an opinion on what to build, and it will be heard Help hire, onboard, and lead future engineering talent as the team scales Represent technical capabilities credibly with investors, partners, and strategic clients Requirements 5-7 years of software engineering experience with a track record of shipping production-grade applications Strong proficiency in React, TypeScript, JavaScript, Node.

js, and CSS Experience building and launching modern web applications from early-stage to production Hands-on experience designing and managing MongoDB database architecture Strong understanding of scalable application architecture and security fundamentals Ability to work independently with minimal oversight

• you define the path when the destination is clear Startup-caliber execution speed and problem-solving mindset Clear, direct communication
• you will work closely with a non-technical founder and must translate clearly in both directions Strongly Preferred Experience building products from 0 to 1 at an early-stage company AWS or cloud deployment experience Product and UI/UX instincts
• you can design a functional, clean interface without a dedicated designer Experience with Base44 platform or similar low-code / pro-code hybrid environments Familiarity with Claude SKILL.

md workflows and AI-assisted development practices Experience integrating AI APIs (Anthropic, OpenAI) into production applications Who thrives here: Builders who want ownership, not instructions. People who make decisions with incomplete information and iterate fast. Engineers who care about the product's business outcome, not just the code.

Who does not:

Candidates who need full specifications before starting. Engineers who treat product decisions as someone else's problem. People who optimize for comfort over impact. This role is structured for someone who wants to build something significant and share meaningfully in the outcome. There is no base salary at inception. The offer is equity-first, with cash compensation triggered by verifiable revenue milestones. Details to be discussed during the interview process.