Legacy System Modernization Without Business Disruption

Rewrites usually fail on production-critical software because (1) the old system encodes years of edge-case business rules nobody remembers, (2) the rewrite freezes new features for 12+ months while competitors keep moving, and (3) all the risk concentrates in a single big-bang cutover. The strangler-fig pattern lets you replace the system one capability at a time, with reversible cutovers — slower but dramatically safer.

Yes. Our team has shipped production migrations from COBOL, Delphi 7, classic ASP, VB6, PowerBuilder, .NET Framework 2/3.5 and PHP 5. We don't typically write new code in those languages — we read them to extract business rules, then build the replacement in modern stacks (.NET 8, Java 21, Node.js, Python).

That's the most common scenario. Phase 1 (Audit) is partly code archaeology — we read the SQL, the stored procedures, the data, and reconstruct the business rules. We pair it with structured interviews of current users (who often know more than they realise). The audit deliverable is partly that missing documentation.

Compliance is a constraint from day one, not a checkpoint at the end. We map current controls (audit logs, RBAC, encryption, retention policies) and ensure each one carries forward. Where the legacy system was already non-compliant (no audit log, weak crypto), modernisation is the cheapest fix — we add controls in the new code while the old system winds down.

For most engagements: minutes, not hours. The strangler-fig pattern means cutover is incremental — we move 1% of traffic, then 10%, then 100%. There's never a moment where 'the system is down for the rebuild'. Even data-layer cutovers use techniques (dual write, gradual table-by-table swap) that keep the application available throughout.

Both, always. Application code is meaningless without the data. Our migrations include: schema design for the new database, ETL scripts (idempotent, restartable), reconciliation tooling that compares row counts and checksums, and a 90-day archival plan so the old database stays accessible for audit even after the application is decommissioned.