Senior Flutter/Laravel Developer — Square Multi-Location Restaurant App (Urgent)

We are seeking a senior Flutter/Laravel developer or established development team to take over, stabilize, and complete an existing live multi-location restaurant ordering platform. This is not a new app build. The platform is already in production and processes real customer orders and payments. Previous developers left unfinished functionality, inconsistencies, and reliability concerns across the mobile apps, backend, Square integration, rewards, notifications, and restaurant operations. This is a revenue-critical project with a two-week deadline for the highest-priority work. You must be able to start immediately and commit sufficient time during this period. Lower-priority interface and copy issues can be completed afterward. PLATFORM AND TECHNOLOGY The existing system includes: • Flutter customer apps for iOS and Android • Laravel backend and APIs • MySQL database • Square Payments, Orders, Locations, OAuth, and webhooks • Square application fees and multi-location routing • Kitchen Display System (KDS) • Restaurant Admin and AppDash interfaces • Customer rewards earning and redemption • Firebase Cloud Messaging and Apple push notifications • Pickup scheduling and order-status tracking • Live production deployment CRITICAL FIRST-MILESTONE WORK 1. Square payments and order reliability The payment and order pipeline must be reviewed from beginning to end. This includes the Flutter app, Laravel backend, Square APIs, webhooks, database records, KDS, and administrative systems. Responsibilities include: • Diagnose payment and order inconsistencies • Verify Square Payments and Orders API implementation • Verify taxes, tips, subtotals, totals, refunds, and application fees • Correct inaccurate “order again” tax calculations • Prevent duplicate charges and duplicate orders • Review and implement proper idempotency where necessary • Verify webhook processing, retry handling, and reconciliation • Review Square OAuth and token handling • Verify correct routing between multiple restaurant locations • Ensure Laravel and Square payment/order records remain consistent • Safely handle failed, interrupted, repeated, or delayed requests 2. Restaurant-system synchronization Orders must remain synchronized across the customer app, Laravel backend, Square, KDS, Admin, and AppDash. The developer must identify and correct missing, delayed, duplicated, or inconsistent orders and status updates. Pickup orders must use appropriate pickup statuses and must not incorrectly display delivery-related information. 3. Customer rewards Review and correct: • Rewards earning after completed orders • Reward redemption • Reward history • Post-order reward balances • Rewards associated with cancelled, failed, or duplicated orders • Test rewards incorrectly appearing for new customers • Consistency between the app, backend, and order/payment status 4. Firebase promotional push notifications This requirement is separate from the notification history displayed inside the app. Restaurant administrators must be able to send promotional push notifications that appear through the native iPhone and Android notification systems, including when the app is running, backgrounded, or fully closed. The review and implementation may include: • Firebase Cloud Messaging configuration • Apple Push Notification service configuration • iOS certificates, keys, entitlements, and permissions • Android notification configuration and permissions • Device-token registration, refresh, storage, and removal • Promotional sends through the administrative system • Customer, topic, or restaurant-location segmentation • Notification-tap behavior and deep linking • Invalid or expired token handling • Delivery logging and failure reporting • Testing on physical iPhone and Android devices 5. Monitoring, deployment, and live verification The platform does not currently have a reliable staging environment that fully reproduces the live payment, webhook, KDS, rewards, and notification workflows. Some functionality may require carefully controlled live testing. The developer must propose and follow a safe process that includes: • Appropriate logging and monitoring before critical testing • Controlled live payments, refunds, and webhook tests • Clear identification and reconciliation of test transactions • Duplicate-payment and duplicate-order safeguards • Database and deployment backups • Documented rollback procedures • Controlled release windows when necessary • End-to-end verification after deployment • Immediate monitoring of production behavior No production payment, refund, deployment, webhook, credential, or configuration change may be made without prior written approval. EXISTING AUDIT An initial audit identified approximately 25 issues, including payment calculations, order responses, search/filter behavior, pickup workflows, Maps configuration, rewards data, interface problems, and deployment requirements. The audit does not fully document or scope all critical systems listed above. The selected developer must review the code and distinguish between: • Confirmed defects • Missing functionality • Working but risky implementations • Correctly working functionality • Items requiring deeper rework • Items that cannot be verified with the current environment Read-only GitHub access to the Flutter and Laravel repositories will be provided to qualified finalists. The issue spreadsheet, screenshots, videos, sanitized logs, and available test accounts will also be provided. REQUIRED EXPERIENCE Do not apply unless you have direct, hands-on production experience with: • Flutter apps released on iOS and Android • Laravel production applications and APIs • Square Payments API • Square Orders API • Square OAuth and webhooks • Square Locations API and multi-location routing • Payment idempotency and duplicate-charge protection • Restaurant ordering, POS, KDS, or food-service systems • Firebase Cloud Messaging and iOS push notifications • Debugging and stabilizing an unfamiliar production codebase • Safe deployment of revenue-critical applications Experience with Stripe or another payment processor alone is not sufficient. You must have personally implemented, maintained, or repaired a production Square integration. DELIVERABLES The selected developer must provide: • Written technical assessment of each critical area • Priority-ranked implementation plan • Two-week critical milestone scope • Estimated hours, price, assumptions, dependencies, and exclusions • Code committed regularly to our designated repository • Documentation explaining important changes • Testing results and evidence • Controlled production-verification results • Deployment and rollback instructions • Final list of completed, postponed, and newly discovered issues WHO SHOULD NOT APPLY Do not apply if: • You do not have direct production Square experience • You cannot start immediately • You cannot commit enough time during the next two weeks • You cannot test on physical iPhone and Android devices • You have never inherited or stabilized an existing live application • You intend to outsource the work to an unidentified developer • You cannot provide regular progress updates • You are submitting a generic proposal without addressing the requirements APPLICATION INSTRUCTIONS Begin your proposal with the words “SQUARE RESTAURANT.” Include: 1. Who will personally perform the work. 2. Your availability and earliest start date. 3. Hours available during the next two weeks. 4. Square APIs and features you personally implemented. 5. Your multi-location restaurant, POS, ordering, or KDS experience. 6. Examples of relevant production applications. 7. Your approach to controlled live-payment testing. 8. How you handle idempotency, webhooks, and reconciliation. 9. Your estimated initial approach and whether you recommend a paid code-review milestone. 10. Confirmation that additional work and costs require written approval. We will select based on proven Square and restaurant-platform experience, availability, testing discipline, communication, technical approach, and realistic delivery commitments—not simply the lowest bid. Strong performance during the initial milestone may lead to ongoing maintenance and development work, including adapting the platform for additional restaurant clients.