ExternalFreelancerRemote$8–$15 USD

Legacy .NET Subscription System Enhancements

Summary

Freelancer Client is hiring: Legacy .NET Subscription System Enhancements.

Location: Remote

Our ten-year-old ASP.NET site drives institutional subscriptions to our publications, granting access by recognised IP ranges and handling one-off PDF sales. The code base still runs on an older .NET Framework, yet we plan to modernise gradually once the critical issues below are under control.

Strengthen billing and payment processing, wiring PayPal into the existing workflow and ensuring transactions post back correctly.

Tighten access control: refine the IP-recognition logic that unlocks content for authorised subscribers and blocks everyone else.

Clean up every customer-facing email and on-screen message generated during purchases, renewals and failed attempts.

Smooth the one-time PDF purchase flow so that a successful PayPal payment instantly activates the download.

Skills: PHP, ASP, .NET, Website Design, PayPal API, Software Development, ASP.NET, Web Development, Database Management, Payment Processing

Budget: $8–$15 USD


Source: Freelancer Client via Remote / Online. Apply on the source website.

Original

Our ten-year-old ASP.NET site drives institutional subscriptions to our publications, granting access by recognised IP ranges and handling one-off PDF sales. The code base still runs on an older .NET Framework, yet we plan to modernise gradually once the critical issues below are under control.

Immediate focus
• Strengthen billing and payment processing, wiring PayPal into the existing workflow and ensuring transactions post back correctly.
• Tighten access control: refine the IP-recognition logic that unlocks content for authorised subscribers and blocks everyone else.
• Clean up every customer-facing email and on-screen message generated during purchases, renewals and failed attempts.
• Smooth the one-time PDF purchase flow so that a successful PayPal payment instantly activates the download.

Deliverables for this phase
1. Technical review and implementation plan outlining code changes, database adjustments and rollout steps.
2. Incremental commits that introduce the new PayPal endpoints, replace or refactor the IP gatekeeping classes, and update message templates.
3. Short test script demonstrating that subscriptions, renewals and one-time sales all complete from payment through content delivery without regression.

Once these items are stable in production we can map out the larger migration path toward a newer .NET version while continuing with incremental enhancements.

Access to the current repository, staging server and some legacy documentation will be provided. Clear commit history, straightforward communication and a reasonable hourly rate are essential as the intention is to establish a long-term working relationship on this platform.

Location & Details

SourceFreelancer
Budget$8–$15 USD
LocationRemote
Posted2026-05-18 15:42:20
PHPASP.NETWebsite DesignPayPal APISoftware DevelopmentASP.NETWeb DevelopmentDatabase ManagementPayment Processing
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About this listing

This remote opportunity was imported from Freelancer and is shown here for discovery. To apply, follow the link to the original posting.

Skills mentioned:
PHPASP.NETWebsite DesignPayPal APISoftware DevelopmentASP.NETWeb DevelopmentDatabase ManagementPayment Processing