diff --git a/daggy/include/daggy/Utilities.hpp b/daggy/include/daggy/Utilities.hpp
index 5d55476..a9c7159 100644
--- a/daggy/include/daggy/Utilities.hpp
+++ b/daggy/include/daggy/Utilities.hpp
@@ -17,6 +17,6 @@ namespace daggy {
 
     ParameterValues parseParameters(const std::string & jsonSpec);
     ParameterValues parseParameters(const rj::Document & spec);
-    // std::vector<Task> buildTasks(const std::string & jsonSpec, const ParameterValues & parameters);
-    // std::vector<Task> buildTasks(const rj::Document & spec, const ParameterValues & parameters);
-}
\ No newline at end of file
+    std::vector<Task> buildTasks(const std::string & jsonSpec, const ParameterValues & parameters);
+    std::vector<Task> buildTasks(const rj::Document & spec, const ParameterValues & parameters);
+}
diff --git a/daggy/src/Utilities.cpp b/daggy/src/Utilities.cpp
index c517b5b..99a8737 100644
--- a/daggy/src/Utilities.cpp
+++ b/daggy/src/Utilities.cpp
@@ -17,6 +17,7 @@ namespace daggy {
             if (! it->name.IsString()) {
                 throw std::runtime_error("All keys must be strings.");
             }
+            std::string name = std::string{"{{"} + it->name.GetString() + "}}";
             if (it->value.IsArray()) {
                 std::vector<std::string> values;
                 for (size_t i = 0; i < it->value.Size(); ++i) {
@@ -25,9 +26,9 @@ namespace daggy {
                     }
                     values.emplace_back(it->value[i].GetString());
                 }
-                parameters[it->name.GetString()] = values;
+                parameters[name] = values;
             } else if (it->value.IsString()) {
-                parameters[it->name.GetString()] = it->value.GetString();
+                parameters[name] = it->value.GetString();
             } else {
                 throw std::runtime_error("Attribute for " + std::string{it->name.GetString()} + " is not a string or an array.");
             }
@@ -35,33 +36,60 @@ namespace daggy {
         return parameters;
     }
 
-    /*
-    std::vector<Task> buildTasks(const std::string & jsonSpec) {
+
+    std::vector<Task> buildTasks(const rj::Document & spec, const ParameterValues & parameters) {
+        std::vector<Task> tasks;
+        if (!spec.IsArray()) { throw std::runtime_error("Tasks is not an array"); }
+
+        const std::vector<std::string> reqFields{"name", "command"};
+        const std::vector<std::string> optionalFields{"max_retries", "retry_interval", "children"};
+
+        // Tasks
+        for (size_t i = 0; i < spec.Size(); ++i) {
+            if (! spec[i].IsObject()) {
+                throw std::runtime_error("Task " + std::to_string(i) + " is not a dictionary.");
+            }
+            const auto & taskSpec = spec[i].GetObject();
+
+            for (const auto reqField : reqFields) {
+                if (! taskSpec.HasMember(reqField.c_str())) {
+                    throw std::runtime_error("Task " + std::to_string(i) + " is missing required field " + reqField);
+                }
+            }
+
+            // Build the first task as-is
+            Task task;
+            task.name = taskSpec["name"].GetString();
+            task.command = taskSpec["command"].GetString();
+
+            if (taskSpec.HasMember("max_retries")) { task.max_retries = taskSpec["max_retries"].GetInt(); }
+            if (taskSpec.HasMember("retry_interval_seconds")) { task.retry_interval_seconds = taskSpec["retry_interval_seconds"].GetInt(); }
+            if (taskSpec.HasMember("children")) {
+                const auto & children = taskSpec["children"].GetArray();
+                for (size_t c = 0; c < children.Size(); ++c) {
+                    task.children.emplace_back(children[c].GetString());
+                }
+            }
+
+            // We need to iterate over the tasks multiple times to interpolate
+            std::vector<Task> taskGroup;
+            taskGroup.push_back(task);
+
+            std::string command = taskSpec["command"];
+
+            Task task;
+            task.name = taskSpec["name"].GetString();
+            task.name = taskSpec["name"].GetString();
+        }
+        return tasks;
+    }
+
+    std::vector<Task> buildTasks(const std::string & jsonSpec, const ParameterValues & parameters) {
         rj::Document doc;
         rj::ParseResult parseResult = doc.Parse(jsonSpec.c_str());
         if (! parseResult) {
             throw std::runtime_error("Unable to parse spec: ");
         }
-        return buildTasks(doc);
+        return buildTasks(doc, parameters);
     }
-
-    std::vector<Task> buildTasks(const rj::Document & spec) {
-        std::vector<Task> tasks;
-        if (!spec.IsObject()) { throw std::runtime_error("Spec is not a JSON dictionary"); }
-
-        // Parameter Parsing
-        auto parameters = parseParameters(spec);
-        // Tasks
-        if (spec.HasMember("tasks")) {
-            auto & sTasks = spec["tasks"];
-            if (! sTasks.IsArray()) {
-                throw std::runtime_error("tasks member must be an array");
-            }
-            for (size_t i = 0; i < sTasks.Size(); ++i) {
-                tasks.push_back(parseTask(sTasks[i]));
-            }
-        }
-        return tasks;
-    }
-    */
-}
\ No newline at end of file
+}
diff --git a/examples/sample_dag.json b/examples/sample_dag.json
index 0fe8c32..b7fb4f9 100644
--- a/examples/sample_dag.json
+++ b/examples/sample_dag.json
@@ -3,24 +3,26 @@
     {
       "name": "pull_data_a",
       "max_retries": 3,
-      "retry_delay_seconds": 600,
-      "command": "/path/to/pull.sh --date {DATE} --source {SOURCE}_A",
-      "verification_command": "/path/to/pull_verify.sh --date {DATE} --source {SOURCE}_A",
-      "timeout_seconds": 30
+      "retry_interval_seconds": 600,
+      "if": "/path/to/should_pull.sh --date {{DATE}} --source {{SOURCE}}_A",
+      "command": "/path/to/pull.sh --date {{DATE}} --source {{SOURCE}}_A",
+      "verification_command": "/path/to/pull_verify.sh --date {{DATE}} --source {{SOURCE}}_A",
+      "timeout_seconds": 30,
       "children": [ "merge_data" ]
     },
     {
       "name": "pull_data_b",
       "max_retries": 3,
-      "retry_delay_seconds": 600,
-      "command": "/path/to/pull.sh --date {DATE} --source {SOURCE}_B",
-      "verification_command": "/path/to/pull_verify.sh --date {DATE} --source {SOURCE}_B",
-      "timeout_seconds": 30
+      "retry_interval_seconds": 600,
+      "if": "/path/to/should_pull.sh --date {{DATE}} --source {{SOURCE}}_B",
+      "command": "/path/to/pull.sh --date {{DATE}} --source {{SOURCE}}_B",
+      "verification_command": "/path/to/pull_verify.sh --date {{DATE}} --source {{SOURCE}}_B",
+      "timeout_seconds": 30,
       "children": [ "merge_data" ]
     },
     {
       "name": "merge_data",
-      "command": "/path/to/merge.sh --left {SOURCE}_A --right {SOURCE}_B"
+      "command": "/path/to/merge.sh --left {{SOURCE}}_A --right {{SOURCE}}_B"
     }
   ]
 }