diff --git a/SeaHaven.DataServices/Implementation/VendorCompanyRosterDataService.cs b/SeaHaven.DataServices/Implementation/VendorCompanyRosterDataService.cs
index cac9637..4b66614 100644
--- a/SeaHaven.DataServices/Implementation/VendorCompanyRosterDataService.cs
+++ b/SeaHaven.DataServices/Implementation/VendorCompanyRosterDataService.cs
@@ -131,6 +131,7 @@ namespace SeaHaven.DataServices.Implementation
             var existingTechnicians = await _context.Vendors
                 .Where(v => v.CompanyId == company.Id && (v.IsDeleted == null || v.IsDeleted == false))
                 .ToListAsync(cancellationToken);
+            var existingTechniciansById = existingTechnicians.ToDictionary(v => v.Id);
 
             var snapshotIds = roster.Technicians
                 .Where(t => t.Id.HasValue)
@@ -169,8 +170,7 @@ namespace SeaHaven.DataServices.Implementation
             {
                 if (technician.Id.HasValue)
                 {
-                    var existing = existingTechnicians.FirstOrDefault(e => e.Id == technician.Id.Value);
-                    if (existing == null)
+                    if (!existingTechniciansById.TryGetValue(technician.Id.Value, out var existing))
                         continue;
 
                     existing.ContactName = technician.ContactName;