diff --git a/src/FilterLists.Api/Migrations/20180127232215_AddScrapedAndUpdatedDates.Designer.cs b/src/FilterLists.Api/Migrations/20180127232215_AddScrapedAndUpdatedDates.Designer.cs
new file mode 100644
index 000000000..6cf92f98c
--- /dev/null
+++ b/src/FilterLists.Api/Migrations/20180127232215_AddScrapedAndUpdatedDates.Designer.cs
@@ -0,0 +1,451 @@
+// <auto-generated />
+using FilterLists.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage;
+using Microsoft.EntityFrameworkCore.Storage.Internal;
+using System;
+
+namespace FilterLists.Api.Migrations
+{
+    [DbContext(typeof(FilterListsDbContext))]
+    [Migration("20180127232215_AddScrapedAndUpdatedDates")]
+    partial class AddScrapedAndUpdatedDates
+    {
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn)
+                .HasAnnotation("ProductVersion", "2.0.1-rtm-125");
+
+            modelBuilder.Entity("FilterLists.Data.Entities.FilterList", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("SMALLINT UNSIGNED");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Description")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("DescriptionSourceUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime?>("DiscontinuedDate");
+
+                    b.Property<string>("DonateUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("EmailAddress")
+                        .HasColumnType("NVARCHAR(126)");
+
+                    b.Property<string>("ForumUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("HomeUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("IssuesUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("LicenseId");
+
+                    b.Property<DateTime>("ModifiedDateUtc")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("NVARCHAR(126) NOT NULL");
+
+                    b.Property<DateTime?>("ScrapedDateUtc");
+
+                    b.Property<string>("SubmissionUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("SyntaxId");
+
+                    b.Property<DateTime?>("UpdatedDateUtc");
+
+                    b.Property<string>("ViewUrl")
+                        .HasColumnType("TEXT NOT NULL");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("LicenseId");
+
+                    b.HasIndex("SyntaxId");
+
+                    b.ToTable("filterlists");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.FilterListLanguage", b =>
+                {
+                    b.Property<int>("FilterListId");
+
+                    b.Property<int>("LanguageId");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.HasKey("FilterListId", "LanguageId");
+
+                    b.HasIndex("LanguageId");
+
+                    b.ToTable("filterlists_languages");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.FilterListMaintainer", b =>
+                {
+                    b.Property<int>("FilterListId");
+
+                    b.Property<int>("MaintainerId");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.HasKey("FilterListId", "MaintainerId");
+
+                    b.HasIndex("MaintainerId");
+
+                    b.ToTable("filterlists_maintainers");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.FilterListRule", b =>
+                {
+                    b.Property<int>("FilterListId");
+
+                    b.Property<int>("RuleId");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.HasKey("FilterListId", "RuleId");
+
+                    b.HasIndex("RuleId");
+
+                    b.ToTable("filterlists_rules");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.Fork", b =>
+                {
+                    b.Property<int>("ForkFilterListId");
+
+                    b.Property<int>("UpstreamFilterListId");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.HasKey("ForkFilterListId", "UpstreamFilterListId");
+
+                    b.HasIndex("UpstreamFilterListId");
+
+                    b.ToTable("forks");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.Merge", b =>
+                {
+                    b.Property<int>("MergeFilterListId");
+
+                    b.Property<int>("UpstreamFilterListId");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.HasKey("MergeFilterListId", "UpstreamFilterListId");
+
+                    b.HasIndex("UpstreamFilterListId");
+
+                    b.ToTable("merges");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.SoftwareSyntax", b =>
+                {
+                    b.Property<int>("SoftwareId");
+
+                    b.Property<int>("SyntaxId");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.HasKey("SoftwareId", "SyntaxId");
+
+                    b.HasIndex("SyntaxId");
+
+                    b.ToTable("software_syntaxes");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Language", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("SMALLINT UNSIGNED");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Iso6391")
+                        .HasColumnType("NVARCHAR(2)");
+
+                    b.Property<string>("Iso6392")
+                        .HasColumnType("NVARCHAR(3)");
+
+                    b.Property<string>("Iso6392B")
+                        .HasColumnType("NVARCHAR(3)");
+
+                    b.Property<string>("Iso6392T")
+                        .HasColumnType("NVARCHAR(3)");
+
+                    b.Property<string>("Iso6393")
+                        .HasColumnType("NVARCHAR(3)");
+
+                    b.Property<string>("LocalName")
+                        .HasColumnType("NVARCHAR(126)");
+
+                    b.Property<DateTime>("ModifiedDateUtc")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("NVARCHAR(126)");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("languages");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.License", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("SMALLINT UNSIGNED");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("DescriptionUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("ModifiedDateUtc")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("NVARCHAR(126) NOT NULL");
+
+                    b.Property<bool>("PermissiveAdaptation");
+
+                    b.Property<bool>("PermissiveCommercial");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("licenses");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Maintainer", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("SMALLINT UNSIGNED");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("EmailAddress")
+                        .HasColumnType("NVARCHAR(126)");
+
+                    b.Property<string>("HomeUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("ModifiedDateUtc")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("NVARCHAR(126) NOT NULL");
+
+                    b.Property<string>("TwitterHandle")
+                        .HasColumnType("NVARCHAR(126)");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("maintainers");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Rule", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("BIGINT UNSIGNED");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Raw")
+                        .HasColumnType("NVARCHAR(2083) NOT NULL");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("rules");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Software", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("SMALLINT UNSIGNED");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("DownloadUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("HomeUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("ModifiedDateUtc")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("NVARCHAR(126) NOT NULL");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("software");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Syntax", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("SMALLINT UNSIGNED");
+
+                    b.Property<DateTime>("CreatedDateUtc")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("DefinitionUrl")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("ModifiedDateUtc")
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("TIMESTAMP");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("NVARCHAR(126) NOT NULL");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("syntaxes");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.FilterList", b =>
+                {
+                    b.HasOne("FilterLists.Data.Entities.License")
+                        .WithMany("FilterLists")
+                        .HasForeignKey("LicenseId");
+
+                    b.HasOne("FilterLists.Data.Entities.Syntax")
+                        .WithMany("FilterLists")
+                        .HasForeignKey("SyntaxId");
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.FilterListLanguage", b =>
+                {
+                    b.HasOne("FilterLists.Data.Entities.FilterList", "FilterList")
+                        .WithMany("FilterListLanguages")
+                        .HasForeignKey("FilterListId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.HasOne("FilterLists.Data.Entities.Language", "Language")
+                        .WithMany("FilterListLanguages")
+                        .HasForeignKey("LanguageId")
+                        .OnDelete(DeleteBehavior.Cascade);
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.FilterListMaintainer", b =>
+                {
+                    b.HasOne("FilterLists.Data.Entities.FilterList", "FilterList")
+                        .WithMany("FilterListMaintainers")
+                        .HasForeignKey("FilterListId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.HasOne("FilterLists.Data.Entities.Maintainer", "Maintainer")
+                        .WithMany("FilterListMaintainers")
+                        .HasForeignKey("MaintainerId")
+                        .OnDelete(DeleteBehavior.Cascade);
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.FilterListRule", b =>
+                {
+                    b.HasOne("FilterLists.Data.Entities.FilterList", "FilterList")
+                        .WithMany("FilterListRules")
+                        .HasForeignKey("FilterListId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.HasOne("FilterLists.Data.Entities.Rule", "Rule")
+                        .WithMany("FilterListRules")
+                        .HasForeignKey("RuleId")
+                        .OnDelete(DeleteBehavior.Cascade);
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.Fork", b =>
+                {
+                    b.HasOne("FilterLists.Data.Entities.FilterList", "ForkFilterList")
+                        .WithMany()
+                        .HasForeignKey("ForkFilterListId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.HasOne("FilterLists.Data.Entities.FilterList", "UpstreamFilterList")
+                        .WithMany()
+                        .HasForeignKey("UpstreamFilterListId")
+                        .OnDelete(DeleteBehavior.Cascade);
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.Merge", b =>
+                {
+                    b.HasOne("FilterLists.Data.Entities.FilterList", "MergeFilterList")
+                        .WithMany()
+                        .HasForeignKey("MergeFilterListId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.HasOne("FilterLists.Data.Entities.FilterList", "UpstreamFilterList")
+                        .WithMany()
+                        .HasForeignKey("UpstreamFilterListId")
+                        .OnDelete(DeleteBehavior.Cascade);
+                });
+
+            modelBuilder.Entity("FilterLists.Data.Entities.Junctions.SoftwareSyntax", b =>
+                {
+                    b.HasOne("FilterLists.Data.Entities.Software", "Software")
+                        .WithMany("SoftwareSyntaxes")
+                        .HasForeignKey("SoftwareId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.HasOne("FilterLists.Data.Entities.Syntax", "Syntax")
+                        .WithMany("SoftwareSyntaxes")
+                        .HasForeignKey("SyntaxId")
+                        .OnDelete(DeleteBehavior.Cascade);
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/src/FilterLists.Api/Migrations/20180127232215_AddScrapedAndUpdatedDates.cs b/src/FilterLists.Api/Migrations/20180127232215_AddScrapedAndUpdatedDates.cs
new file mode 100644
index 000000000..027ef4fa1
--- /dev/null
+++ b/src/FilterLists.Api/Migrations/20180127232215_AddScrapedAndUpdatedDates.cs
@@ -0,0 +1,32 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+namespace FilterLists.Api.Migrations
+{
+    public partial class AddScrapedAndUpdatedDates : Migration
+    {
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<DateTime>(
+                "ScrapedDateUtc",
+                "filterlists",
+                nullable: true);
+
+            migrationBuilder.AddColumn<DateTime>(
+                "UpdatedDateUtc",
+                "filterlists",
+                nullable: true);
+        }
+
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                "ScrapedDateUtc",
+                "filterlists");
+
+            migrationBuilder.DropColumn(
+                "UpdatedDateUtc",
+                "filterlists");
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/FilterLists.Api/Migrations/FilterListsDbContextModelSnapshot.cs b/src/FilterLists.Api/Migrations/FilterListsDbContextModelSnapshot.cs
index 809a83891..4c4d78ead 100644
--- a/src/FilterLists.Api/Migrations/FilterListsDbContextModelSnapshot.cs
+++ b/src/FilterLists.Api/Migrations/FilterListsDbContextModelSnapshot.cs
@@ -60,11 +60,15 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                 b.Property<string>("Name")
                     .HasColumnType("NVARCHAR(126) NOT NULL");
 
+                b.Property<DateTime?>("ScrapedDateUtc");
+
                 b.Property<string>("SubmissionUrl")
                     .HasColumnType("TEXT");
 
                 b.Property<int?>("SyntaxId");
 
+                b.Property<DateTime?>("UpdatedDateUtc");
+
                 b.Property<string>("ViewUrl")
                     .HasColumnType("TEXT NOT NULL");
 
diff --git a/src/FilterLists.Data/Entities/FilterList.cs b/src/FilterLists.Data/Entities/FilterList.cs
index 05a3c2ddb..b151e5d08 100644
--- a/src/FilterLists.Data/Entities/FilterList.cs
+++ b/src/FilterLists.Data/Entities/FilterList.cs
@@ -20,8 +20,10 @@ public class FilterList
         public string IssuesUrl { get; set; }
         public int? LicenseId { get; set; }
         public string Name { get; set; }
+        public DateTime? ScrapedDateUtc { get; set; }
         public string SubmissionUrl { get; set; }
         public int? SyntaxId { get; set; }
+        public DateTime? UpdatedDateUtc { get; set; }
         public string ViewUrl { get; set; }
 
         public ICollection<FilterListLanguage> FilterListLanguages { get; set; }
diff --git a/src/FilterLists.Data/Seed/Extensions/SeedFilterListsDbContext.cs b/src/FilterLists.Data/Seed/Extensions/SeedFilterListsDbContext.cs
index 21a51cd61..01ab21ea4 100644
--- a/src/FilterLists.Data/Seed/Extensions/SeedFilterListsDbContext.cs
+++ b/src/FilterLists.Data/Seed/Extensions/SeedFilterListsDbContext.cs
@@ -47,8 +47,10 @@ private static void InsertOnDuplicateKeyUpdate<TEntityType>(this DbContext dbCon
 
         private static List<IProperty> GetPropertiesLessValueGeneratedTimestamps(IEntityType entityType)
         {
-            return entityType.GetProperties().Where(x => x.Name != "CreatedDateUtc" && x.Name != "ModifiedDateUtc")
-                .ToList();
+            //TODO: filter dynamically from JSON
+            return entityType.GetProperties().Where(x =>
+                !new List<string> {"CreatedDateUtc", "ModifiedDateUtc", "ScrapedDateUtc", "UpdatedDateUtc"}
+                    .Contains(x.Name)).ToList();
         }
 
         private static string CreateValues<TEntityType>(IReadOnlyCollection<IProperty> properties, string dataPath)
diff --git a/src/FilterLists.Services/Services/ScrapeService.cs b/src/FilterLists.Services/Services/ScrapeService.cs
index 6a934387b..dd355d067 100644
--- a/src/FilterLists.Services/Services/ScrapeService.cs
+++ b/src/FilterLists.Services/Services/ScrapeService.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Net.Http;
 using System.Threading.Tasks;
@@ -18,56 +19,81 @@ public ScrapeService(FilterListsDbContext filterListsDbContext)
             this.filterListsDbContext = filterListsDbContext;
         }
 
-        public async Task Scrape()
+        public async Task Scrape(int numberLists)
         {
-            //TEMP: remove Take(1) when algorithm complete
-            var lists = await filterListsDbContext.FilterLists.Take(1).ToListAsync();
-            foreach (var list in lists) await ScrapeList(list);
+            var lists = filterListsDbContext.FilterLists.OrderBy(x => x.ScrapedDateUtc).Take(numberLists)
+                .Select(x => new FilterListDto {Id = x.Id, ViewUrl = x.ViewUrl});
+            var snapshots = await GetSnapshots(lists);
+            await AddOrUpdateRules(snapshots);
+            //TODO: update FilterList.ScrapedDateUtc
         }
 
-        private async Task ScrapeList(FilterList list)
+        private static async Task<IEnumerable<Snapshot>> GetSnapshots(IEnumerable<FilterListDto> lists)
+        {
+            var snapshots = new List<Snapshot>();
+            foreach (var list in lists)
+                snapshots.Add(new Snapshot {Content = await GetContent(list.ViewUrl), FilterListId = list.Id});
+            return snapshots;
+        }
+
+        //TODO: move to string (URL) extension method
+        private static async Task<string> GetContent(string url)
         {
-            var snapshot = await GetContent(list.ViewUrl);
             try
             {
-                if (snapshot == null) return;
+                using (var httpClient = new HttpClient())
+                {
+                    using (var httpResponseMessage = await httpClient.GetAsync(url))
+                    {
+                        if (httpResponseMessage.IsSuccessStatusCode)
+                            return await httpResponseMessage.Content.ReadAsStringAsync();
+                    }
+                }
             }
             catch (Exception)
             {
-                //TODO: log exception
-                return;
-            }
-
-            await AddRules(list, snapshot);
-        }
-
-        private static async Task<string> GetContent(string url)
-        {
-            using (var httpClient = new HttpClient())
-            {
-                using (var httpResponseMessage = await httpClient.GetAsync(url))
-                {
-                    if (httpResponseMessage.IsSuccessStatusCode)
-                        return await httpResponseMessage.Content.ReadAsStringAsync();
-                }
+                //TODO: log exception for analysis
+                return null;
             }
 
+            //TODO: log httpResponseMessage.StatusCode for analysis
             return null;
         }
 
-        private async Task AddRules(FilterList list, string snapshot)
+        private async Task AddOrUpdateRules(IEnumerable<Snapshot> snapshots)
         {
-            var lines = snapshot.Split(new[] {"\r\n", "\r", "\n"}, StringSplitOptions.None);
+            foreach (var snapshot in snapshots)
+                await AddOrUpdateRules(snapshot);
+        }
 
-            foreach (var line in lines)
+        private async Task AddOrUpdateRules(Snapshot snapshot)
+        {
+            var cachedRules = filterListsDbContext.FilterListRules
+                .Where(x => x.FilterListId == snapshot.FilterListId)
+                .Select(x => x.Rule);
+
+            IEnumerable<string> currentRulesRaw =
+                snapshot.Content.Split(new[] {"\r\n", "\r", "\n"}, StringSplitOptions.None);
+
+            var existingCurrentRules = filterListsDbContext.Rules.Where(x => currentRulesRaw.Contains(x.Raw));
+
+            var deletedRules = cachedRules.Except(existingCurrentRules).ToList();
+
+            filterListsDbContext.FilterListRules.RemoveRange(filterListsDbContext.FilterListRules
+                .Where(x => deletedRules.Select(y => y.Id).Contains(x.RuleId))
+                .Where(x => x.FilterListId == snapshot.FilterListId));
+
+            //TODO: update FilterList.UpdatedDateUtc
+
+            foreach (var line in currentRulesRaw)
             {
                 if (string.IsNullOrWhiteSpace(line)) continue;
                 var rule = new Rule {Raw = line};
                 if (!await filterListsDbContext.Rules.AnyAsync(x => x.Raw == rule.Raw))
                     filterListsDbContext.Rules.Add(rule);
-                var filterListRule = new FilterListRule {FilterList = list, Rule = rule};
+                var filterListRule = new FilterListRule {FilterListId = snapshot.FilterListId, Rule = rule};
                 if (!await filterListsDbContext.FilterListRules.AnyAsync(x =>
-                    x.RuleId == rule.Id && x.FilterListId == list.Id))
+                    x.RuleId == rule.Id && x.FilterListId == snapshot.FilterListId))
                     filterListsDbContext.FilterListRules.Add(filterListRule);
                 filterListsDbContext.FilterListRules.Add(filterListRule);
             }
@@ -81,5 +107,17 @@ private async Task AddRules(FilterList list, string snapshot)
                 //TODO: log exception
             }
         }
+
+        private class FilterListDto
+        {
+            public int Id { get; set; }
+            public string ViewUrl { get; set; }
+        }
+
+        private class Snapshot
+        {
+            public string Content { get; set; }
+            public int FilterListId { get; set; }
+        }
     }
 }
\ No newline at end of file