[Beginner question] Building a Program with Async Functions and Error Logging

class F1Error {
  readonly _tag = "F1Error"
}

class F2Error {
  readonly _tag = "F2Error"
}

function f1(n: number) {
  return pipe(
    Effect.logInfo(`Starting f1: ${n}`),
    Effect.flatMap(() =>
      Effect.promise(() => (Math.random() > 0.5 ? Promise.reject(new F1Error()) : Promise.resolve(n * 2))),
    ),
    Effect.tap((res) => Effect.logInfo(`Ending f1: ${n} => ${res}`)),
  )
}

function f2(input: number) {
  return pipe(
    Effect.logInfo(`Starting f2: ${input}`),
    Effect.flatMap(() =>
      Effect.promise(() =>
        Math.random() > 0.5 ? Promise.reject(new F2Error()) : Promise.resolve(input.toLocaleString()),
      ),
    ),
    Effect.tap((res) => Effect.logInfo(`Ending f2: ${input} => ${res}`)),
  )
}

const program = pipe(
  f1(1),
  Effect.flatMap(f2),
  Effect.catchTags({
    F1Error: () => Effect.logError("F1 failed"),
    F2Error: () => Effect.logError("F2 failed"),
  }),
)

Effect.runPromise(program)