Financial Reporting Platform Modernization for a Federal Acquisition Program

The challenge

The platform served a federal acquisition program tracking hundreds of contracts, task orders, periods of performance, and cost reports across multiple contractors and departments. Over years of incremental development, the reporting layer had fragmented into 30+ isolated pages — each with its own filter setup, no shared state, and no bookmarkable views. Users re-entered contractor, contract, and period-of-performance selections on every page. The embedded report server was a standalone infrastructure dependency requiring separate maintenance and licensing.

The application ran on ASP.NET WebForms — a stack with no upgrade path to .NET Core. Session keys were used to pass filter state between pages, making navigation context fragile and non-shareable. Authentication had accumulated multiple conflicting library versions across partial integration work over the years.

The organization needed a migration path that preserved the existing stored procedures — which contained production-validated government financial calculations — reduced the report server dependency, and delivered a measurably better user experience without a full-stop rewrite that risked service continuity.

The approach

We began with a structured pre-work phase: auditing all session state keys across the codebase, mapping each key to its producer and consumer pages, cataloguing stored procedure parameters that had been sourced from session state, and assessing the legacy data layer for overlap with the write-side domains scheduled for migration. This audit drove migration sequencing and prevented hidden session dependencies from surfacing mid-implementation.

The migration strategy was strangler fig — a new ASP.NET Core 9 API and React 18 SPA ran alongside the legacy system, sharing the same SQL Server database, consuming one domain at a time. The legacy application continued operating for all write operations and non-migrated reports throughout. The reporting workspace was redesigned from the ground up: a single 6-tab shell with a persistent global filter bar, full URL state encoding for every filter and tab combination, and live financial dashboard data from existing stored procedures called via Dapper with no proc changes.