Senior Full-Stack / Platform Engineer — Fractional SaaS Technical Oversight

Senior Fractional SaaS / Full-Stack Engineer for Production CRM Platform I am looking for an experienced Senior Full-Stack SaaS Engineer / Platform Engineer to provide independent technical oversight, production troubleshooting, architecture review, automated testing, and long-term engineering support for an existing construction-industry CRM platform called ForgeOne CRM. This is not a project to build a new application from scratch. ForgeOne is already a substantial working SaaS application with multiple modules, user roles, business workflows, customer/job management functionality, integrations, mobile and desktop interfaces, and an expanding feature set. The platform has been developed rapidly with significant use of modern AI-assisted development tools. That has allowed us to move very quickly, but the application is now reaching the point where I want an experienced senior engineer involved to help transition the development process from rapid feature-building into a more mature production environment with stronger automated testing, monitoring, release controls, architecture oversight, and regression prevention. I am the founder/business owner, not a traditional software engineer. I need someone who can understand the technical side deeply while also communicating clearly with me in normal business language. This will initially be a fractional/part-time position, approximately 5–10 hours per week depending on what is happening. If the relationship is successful and ForgeOne continues growing, this could potentially develop into a much larger role or eventually a full-time technical leadership/engineering position. What I Need My biggest priority is production reliability. As ForgeOne has grown, there are now enough interconnected features that making a change in one area can potentially create an unexpected issue somewhere else. I do not want to rely solely on the founder, employees, customers, or subcontractors manually discovering regressions after a release. I want to develop a proper engineering safety net around the platform. The person I hire should be capable of looking at the entire application as a system rather than only working on individual frontend tickets. You should be comfortable investigating problems across: * Frontend * Backend * APIs * Database * Authentication * User permissions * Multi-tenant data separation * Third-party integrations * Browser/mobile behavior * Deployment * Logging * Monitoring * Automated testing * Production infrastructure * Security Initial Assignment — Production Readiness / Architecture Audit The first thing I want is an independent technical review of the existing ForgeOne platform. I want someone experienced to examine how the system is currently structured before making major recommendations or changes. The review should include areas such as: * Overall SaaS architecture * Code organization and maintainability * Frontend/backend interaction * Database design * Multi-tenant architecture * Company/tenant data isolation * Authentication * Authorization and role-based permissions * API design * Third-party API integrations * Error handling * Logging * Production monitoring * Security * Secrets/environment configuration * Deployment process * Database migrations * Backup/recovery considerations * Performance * Scalability * Mobile responsiveness * Automated testing coverage * Release/change-management process * Technical debt that creates actual business risk I would like findings categorized approximately as: Critical — immediate production, security, data, or operational risk. High — should be corrected before significant customer growth. Medium — important improvements that should be placed on the engineering roadmap. Low — optimization, cleanup, or longer-term technical improvements. I also want the engineer to identify what is currently working well. I am not looking for someone who automatically recommends rebuilding everything because they prefer another framework or architecture. If part of the existing application works correctly, is secure, scalable enough for our requirements, and can be maintained, I want that taken into consideration. Changes should be driven by actual technical or business reasons. Automated Regression Testing A major project I want implemented is a comprehensive automated testing system that acts like real ForgeOne users. The goal is to automatically test critical workflows after changes instead of waiting for a human user to discover that something stopped working. I am interested in browser-based end-to-end testing using Playwright or an equivalent framework. Examples of workflows that should eventually be automatically tested include: * User login * New-user invitations * Invitation acceptance * Authentication * User permissions * Company/tenant separation * Dashboard loading * Navigation * Creating jobs * Opening existing jobs * Editing job information * Estimates * Saving information and returning to it * File uploads * Photo uploads * Multiple-file uploads * Customer workflows * Employee workflows * Subcontractor workflows * Notifications * Status/workflow changes * Mobile navigation * Desktop navigation * Responsive layouts * Major CRM modules * Third-party integration screens * Error states * Permission restrictions I want a structured test environment/test company using controlled test data rather than automated testing that performs destructive actions against real customer information. External integrations that could create real financial or operational transactions must be handled appropriately through sandbox environments, mocks, test accounts, or other safeguards. Production Monitoring I also want much stronger visibility into what is happening when something fails. I am interested in implementing or improving tools such as: * Sentry or equivalent application monitoring * Frontend error reporting * Backend error reporting * API failure tracking * Performance monitoring * Browser console error capture * Failed network request capture * Deployment/version tracking * Useful diagnostic logs * Screenshots or traces from failed automated tests When an automated test fails, I want enough information available that an engineer can quickly determine what happened rather than spending hours trying to reproduce an unknown problem. AI Reliability / Diagnostic Agent Another area I am interested in developing is an internal AI Reliability Agent. The AI should NOT have unrestricted authority to modify production code, production databases, or customer information. The primary purpose would be: * Monitoring * Testing * Diagnosing * Comparing failures with recent changes * Organizing logs * Identifying possible causes * Generating incident summaries * Helping prioritize issues * Suggesting possible fixes * Assisting engineers with investigation For example, if an automated browser test fails while opening a job, the ideal system could collect information such as: * Which test failed * Expected behavior * Actual behavior * Screenshot * Browser console errors * Network/API failures * Relevant application logs * Deployment/version * Recently modified files * Potential source of regression The AI could then help analyze that information and provide an engineer with a useful starting point. I want AI helping engineering, not AI operating production without appropriate controls. Experience with the OpenAI API, AI agents, LLM integrations, developer tooling, or AI-assisted diagnostics is valuable, but strong traditional software engineering experience is more important to me than someone whose primary background is prompt engineering. Release Process I want help developing a safer release process. The eventual goal is something similar to: Development/change → automated tests → code/technical review → staging/testing → approval → production deployment → production smoke tests → monitoring Critical workflows should be tested before a release is considered successful. I also want guidance on sensible rollback procedures when a production change creates a regression. Third-Party Integrations ForgeOne includes and is developing multiple third-party integrations. The engineer should be comfortable reviewing and troubleshooting: * REST APIs * OAuth/authentication flows * Webhooks * API credentials * Rate limits * Error handling * Retries * Sandbox versus production environments * Integration security * Data synchronization * Failure recovery Some integrations involve construction-industry suppliers and other outside service providers, so protecting credentials and preventing unintended external transactions is extremely important. Additional details regarding integrations and architecture can be provided to qualified candidates after appropriate confidentiality protections are in place. Security / Multi-Tenant SaaS Experience Multi-tenant security is extremely important. ForgeOne supports multiple independent companies using the same SaaS platform. I need someone who understands that authentication alone is not sufficient. The architecture must ensure that one customer/company cannot access another company’s: * Jobs * Customers * Employees * Financial information * Files * Photos * Communications * Credentials * Integration information * Other tenant-specific data Experience reviewing authorization, RBAC, tenant isolation, database access controls, API authorization, and SaaS security is highly desirable. Who I Am Looking For I am looking for a senior engineer who has actually supported real production SaaS applications. Ideal experience includes several of the following: * Senior full-stack development * SaaS application architecture * Multi-tenant applications * Modern JavaScript/TypeScript development * Modern frontend frameworks * Backend development * SQL/relational databases * API development * REST APIs * Authentication * Authorization * RBAC * Third-party integrations * Git/GitHub * CI/CD * GitHub Actions or equivalent * Playwright * Cypress or other automated E2E testing * Production monitoring * Sentry or equivalent * Cloud deployment * SaaS security * Performance troubleshooting * Production incident investigation * AI-assisted development * OpenAI/LLM integrations * AI agent development Experience with CRM, ERP, field-service, construction-management, project-management, fintech, insurance, or other workflow-heavy SaaS platforms is a strong plus. The exact technology stack and repository architecture can be discussed with shortlisted candidates rather than making assumptions in this posting. What I Am NOT Looking For I am not looking primarily for: * Desktop IT support * Help desk support * Network administration * Basic website development * WordPress development * Landing-page development * Someone learning SaaS development for the first time * A prompt engineer with limited traditional software engineering experience * An agency sending a salesperson while an unknown developer actually performs the work * Someone who immediately wants to rebuild the entire application before understanding it I want to communicate directly with the engineer who will actually be reviewing and working on ForgeOne. Working Style I move quickly and appreciate clear communication. I do not need technical terminology used simply for the sake of sounding technical. When there is a problem, I want an engineer capable of explaining: 1. What is wrong. 2. Why it matters. 3. What caused it or what likely caused it. 4. What options we have. 5. What they recommend. 6. What could potentially be affected by the change. 7. How we test the fix. 8. How we prevent the same problem from happening again. I value engineers who understand that the objective is not merely to make a bug disappear. The objective is to make the product more reliable after every fix. Engagement This will begin as an hourly fractional engagement. Expected initial involvement is approximately 5–10 hours per week, although hours may increase or decrease depending on the project phase. The first major deliverable will be the technical/production-readiness assessment. If that goes well, I would like the relationship to continue into: * Production stabilization * Automated regression testing * Monitoring * Release-process improvements * Architecture oversight * Security improvements * Integration review * Difficult production debugging * AI Reliability Agent development * Ongoing engineering consultation For the right person, this could become a significant long-term role as ForgeOne grows and could potentially transition into a full-time position in the future. When Applying Please do not send a generic copy-and-paste proposal. Please answer the following: 1. Describe a production SaaS application you personally worked on and what your responsibility was. 2. Have you taken over or audited an application that was developed rapidly and needed stabilization? What did you find and what did you do? 3. Describe your experience with multi-tenant SaaS applications and tenant data isolation. 4. What experience do you have with authentication, authorization, and RBAC? 5. What automated end-to-end testing tools have you used? 6. Specifically, what experience do you have with Playwright, Cypress, or similar browser automation? 7. What production monitoring/error-tracking systems have you implemented? 8. What is your experience troubleshooting difficult production regressions? 9. Have you worked with applications developed using AI-assisted coding tools? 10. Have you built AI agents or LLM-powered engineering/operations tools? If yes, briefly explain what they did. 11. If you discovered that an existing part of ForgeOne was designed differently than you personally would have designed it, how would you determine whether to leave it alone, improve it, or replace it? 12. Are you comfortable beginning with a paid technical audit before assuming broader responsibility? Please begin your proposal with “ForgeOne Review” so I know you read the posting. I am looking for an experienced engineer who can become a trusted independent technical resource for ForgeOne—not simply someone to complete isolated coding tickets.