The Template Method pattern defines the skeleton of an algorithm in a base class while letting subclasses override specific steps, which promotes reuse and a consistent process but can become rigid if too many variations are needed.
Key Points: • Advantage: eliminates duplicated boilerplate by centralizing the overall algorithm structure in one place. • Advantage: enforces a consistent process flow across all subclasses, reducing the chance of steps being skipped or reordered incorrectly. • Advantage: lets subclasses customize only the steps that need to vary, via hook or abstract methods. • Limitation: the overall algorithm structure is fixed, so it's a poor fit when the sequence of steps itself needs to change per subclass. • Limitation: deep or wide class hierarchies can become hard to follow and maintain if too many step variations pile up.
Example: A DataProcessor base class might define a fixed process() method that calls readData(), transform(), and saveData() in order, letting CsvProcessor and JsonProcessor subclasses override just the readData() and saveData() steps while sharing the same overall flow.
Interview Tip: A concise interview answer is:
"Template Method's advantage is reusing a fixed algorithm skeleton while letting subclasses customize individual steps, which cuts duplication and enforces a consistent process — its main limitation is that the overall flow is locked in, so it becomes rigid or leads to hierarchy bloat if many subclasses need to reorder or skip steps."