Civil PE Surveying Review (CPESR) is a solo-operated SaaS business that helps civil engineers prepare for the California Civil Professional Engineer exam. Over several phases, Endertech partnered with CPESR to evolve a successful but aging online course into a modern learning platform with a quiz bank, video-based learning center, integrated payments, and, most recently, a shared AI automation layer.
Client Context
CPESR serves a focused, high-stakes niche: civil engineers preparing for a professional licensing exam. The business is run by a single owner who both teaches and operates the service. That structure demands:
Reliable, self-service tools for students to study and track progress
Straightforward administration that one person can manage
Technology that can grow over time without requiring an internal IT team
Before engaging Endertech, CPESR already had a legacy course system and marketing site. The next step was to build a paid quiz bank and, later, a more complete learning center that could sustain and grow the business as an online platform.
The Business Challenges
Across multiple engagements, CPESR and Endertech addressed a series of related challenges:
Productize exam prep content. Create a paid online quiz bank and learning center with accounts, subscriptions, and integrated payments.
Modernize a legacy stack. Incrementally upgrade an older Symfony/PHP codebase across several major versions while cleaning up deprecations and hardening the application.
Support rich learning experiences. Add video-based courses, course quizzes, dashboards, and performance reporting so students can monitor and improve their exam readiness.
Streamline instructor workload. Introduce a moderated Q&A system and, later, AI-assisted workflows for email and Q&A, without sacrificing quality, safety, or auditability.
Keep operations manageable for a solo owner. Provide simple, unified administration tools instead of complex multi-role back-office software.
The Opportunity
By tackling these challenges, CPESR aimed to move from a single course offering into a scalable exam-prep platform. That meant:
Offering differentiated products (quiz bank, learning center, reference manual, and bundles)
Giving students a structured path through videos, quizzes, and progress dashboards
Reducing manual tasks like answering repetitive questions and composing detailed email responses
Building a technical foundation that could keep up with modern PHP/Symfony standards and new capabilities like AI
Endertech’s Role
Endertech served as CPESR’s long-term technical partner, responsible for:
Designing and developing the initial Quiz Bank system
Extending the platform with a Learning Center, dashboard, and additional products
Managing a structured modernization program for the Symfony/PHP stack
Designing and implementing a shared AI automation platform powering email drafts and Q&A support
Formal proposals defined phases for each major initiative—Design, Development, Testing, Launch, and Support—along with roles such as architect, project manager, designer, and lead developer. Work was executed in multi-week sprints with a detailed Jira backlog guiding scope and priorities.
Our Approach
Phase 1: Quiz Bank & Core Platform
The first major initiative was the CPESR Quiz Bank (CQB), an online test-prep system built specifically for civil engineering exam content. Endertech began with a planning phase to translate CPESR’s subject-matter expertise and design ideas into a detailed Jira backlog and application architecture.
The team then followed an iterative, sprint-based process:
Design: Create an updated visual style for the marketing and application pages and produce key page blueprints for the Quiz Bank experience.
Development: Implement features in two-week sprints, with regular checkpoints and demos.
Testing: Have project management verify each feature and deploy to staging environments for client review.
Deployment support: Prepare the application for deployment to a modern Linux server environment.
Phase 2: Learning Center & Expanded Products
After the Quiz Bank, CPESR engaged Endertech for a Learning Center expansion. This phase introduced video-based instruction, additional products, and richer student dashboards. Endertech again used a Jira-driven backlog and phased plan to add capabilities without disrupting existing Quiz Bank behavior.
Phase 3: Modernization & Application Hardening
As the platform matured, Endertech led a structured modernization effort. The goal was to move the Symfony application and PHP runtime through multiple major versions while maintaining stability and compatibility.
Phase 4: Shared AI Automation Platform
Most recently, CPESR and Endertech collaborated on an AI automation initiative. Rather than build one-off integrations, Endertech designed a shared AI platform inside the existing Symfony 7.4 application to support multiple workflows—specifically AI-assisted email drafting and AI-supported Q&A.
What We Delivered
Quiz Bank: Paid Test-Prep Engine
The CPESR Quiz Bank established the core of the online platform:
Question & answer bank: A structured database of questions with possible answers and a single correct answer, organized by categories and problem types.
Configurable test center: Students can configure different types of tests and take them in the browser while the system tracks timing and progress.
Performance reporting: Summary and detailed performance views, from overall metrics across tests to per-test and per-question insights.
Accounts & access control: Students create accounts, manage profiles, and receive secure access to paid content.
Payment integration: Integration with a third-party payment system (including PayPal and links to the legacy course/Moodle system) so subscriptions can be purchased and renewed.
Learning Center: Video Courses & Student Dashboard
The Learning Center proposal and subsequent work expanded CPESR beyond question practice into a fuller LMS experience:
Video-based courses: A learning center where students can watch categorized instructional videos and then complete associated course quizzes.
Product variants & bundling: Support for multiple product types—Quiz Bank, Quiz Bank + Learning Center, and a reference manual—along with upgrade paths and time-based access options.
Student dashboard: A unified dashboard displaying Learning Center progress, Test Center progress, news and announcements, and a student’s exam date.
Preview & upsell flows: Students who only purchase the Quiz Bank can preview selected Learning Center videos and quizzes, with clear options to upgrade.
Admin tools: Admin interfaces to create and manage learning center videos, course quizzes, purchase options, and transactions.
Q&A and Notifications: Managing Student Questions at Scale
To support more interactive learning while keeping operations manageable for a single instructor, Endertech implemented structured Q&A features:
Per-question Q&A: Students can ask questions tied directly to specific quiz questions.
Threaded discussions: Students and the instructor can reply, with threaded lists of questions and answers.
Engagement signals: Students can like questions or answers, influencing their sort order so the most useful content rises to the top.
Notifications: When a student’s question receives an answer, the system surfaces a notification indicator after login and links directly to the relevant thread.
In the Learning Center, questions can also be tied to a specific timestamp within a video, giving the instructor context and helping future students find relevant explanations.
Platform Modernization: Symfony Upgrades & Hardening
Over time, the CPESR application needed to stay current with modern PHP and Symfony versions. Endertech approached this as a disciplined modernization program:
Multi-hop upgrades: Plan and execute upgrades across major Symfony versions (for example, 4.4 → 5.4 → 6.4 → 7.4) rather than attempting a risky single leap.
Deprecation remediation: Use tools like static analysis (e.g., PHPStan rules), automated refactoring utilities (e.g., Rector), and profiler-driven sweeps to eliminate deprecated patterns and stabilize the codebase.
Staging environments: Maintain multiple staging URLs and environments to support iterative testing, QA, and client review during each upgrade step.
Application hardening: Remove legacy bundles, modernize dependencies, and refine configuration to improve reliability and maintainability.
This work reduced technical debt and positioned CPESR to adopt new features—like AI automation—on a modern, supportable foundation.
Shared AI Automation Platform
To further support the solo operator and improve responsiveness to students, Endertech designed and implemented a shared AI platform within the existing Symfony 7.4 application. The goal was to power multiple AI-enabled workflows while keeping safety and oversight front and center.
Core AI Platform Capabilities
Centralized Responses API client: A shared client to communicate with the OpenAI Responses API, so all AI features use a common, maintainable integration.
Prompt domain model: A structured representation of prompts that can be reused, versioned, and managed through the admin interface.
Centralized configuration: Unified settings for model parameters, timeouts, and safety controls.
Structured logging: A shared logging model to record AI requests and responses for auditability and troubleshooting.
Validation & fallbacks: Guardrails that validate AI responses and provide safe fallbacks in case of errors or unexpected output.
Administration & Human-in-the-Loop Controls
Given that CPESR is operated by a single person, Endertech emphasized operational control over automation. Sonata Admin is used to:
Manage and adjust prompts without code changes
Review AI logs in a read-only, centralized interface
Support published-state controls and reviewer-visible conventions so AI-generated content can be checked before it becomes student-facing
AI-Powered Workflows: Email & Q&A
On top of the shared AI foundation, Endertech scoped two initial workflows:
Email draft assistance: Gmail integration to collect relevant context, identify which messages are eligible for AI help, and generate thread-aware draft replies that the instructor can review and send. This is backed by mailbox auditing and logic to keep AI assistance within safe boundaries.
Q&A support: Integration between the existing Q&A system and the AI pipeline to help generate draft answers based on accumulated question history and content context, again with explicit controls for admin review and published-state management.
The CPESRAI backlog shows that the shared platform sprint (architecture, config, Responses API client, prompt and logging models) was completed first, followed by workflow-specific epics for Gmail intake, draft generation, and Q&A context assembly and review controls. This structure maximizes reuse and keeps the AI features aligned with the underlying business workflows.
Complexity Handled
While CPESR is a small business, the underlying system involves meaningful technical and operational complexity:
Coordinating multiple products (quiz bank, learning center, reference manual) with distinct access rules and upgrade paths
Integrating with external systems such as PayPal and a legacy Moodle-based course environment
Managing multi-hop framework and PHP upgrades with extensive deprecation cleanup and compatibility work
Designing a shared AI platform that serves multiple workflows without duplicating integration logic
Implementing secure, audited Gmail connectivity for production-safe email automation
Migrating and backfilling Q&A data while preserving existing visibility semantics when adding published-state support
Results & Business Value
Because this case study is based on internal project materials and proposals, formal business metrics (revenue, user counts, conversion rates) are not included. However, the work clearly delivered several important forms of value:
A focused exam-prep platform: CPESR moved beyond a single course into a structured, productized online service with quiz bank, learning center, and supporting tools.
Stronger student experience: Students gain configurable tests, detailed performance reporting, a video-based learning center, and dashboards that keep exam preparation organized.
Reduced operational friction: Admin interfaces, integrated payments, Q&A tools, and AI-assisted workflows are designed to keep the platform manageable for a solo operator.
Modernized technical foundation: A staged upgrade path and hardening work brought the Symfony application in line with current best practices, reducing technical risk and enabling new capabilities.
Reusable AI infrastructure: A shared AI platform now underpins email drafting and Q&A features, so future AI-powered workflows can be added without reinventing the integration each time.
Why This Work Matters
This engagement demonstrates how a small, specialized education business can benefit from the same caliber of architecture, modernization, and AI strategy that larger organizations use—without losing the personal touch of a solo instructor.
For prospective clients, CPESR shows that Endertech can:
Turn subject-matter expertise into a robust SaaS-style learning platform
Plan and execute complex framework upgrades with minimal disruption
Integrate payments, legacy systems, and modern admin tools into a cohesive whole
Introduce AI into real workflows carefully, with human-in-the-loop controls and strong auditability
Related Services
If you are operating—or planning—an online education, certification prep, or professional training business, Endertech can help you:
Design and build custom LMS and exam-prep platforms
Integrate payments, subscriptions, and product bundles
Modernize legacy PHP/Symfony or other web applications
Implement AI-assisted workflows for content, support, and communications
Provide ongoing support and iterative improvements as your platform grows
Have a similar ecommerce, LMS, or AI integration challenge? Endertech helps businesses design, build, and improve the digital systems that support growth.