Q:

Non UTC-timestamp presented as UTC (zulu) in Sesam DTL

When you use datetime-shift to change to a different timezone, the timestamp still keeps the Z, indicating that the timestamp is UTC.  This is also kept if you convert the timestamp to string.  The only option is to use the datetime-format to remove it, but should it be like that? 
 "transform": {
    "type": "dtl",
    "rules": {
      "default": [
        ["add", "1utc-time-input", "2017-04-12T22:00:00.74Z"],
        ["add", "2utc-parsed",
            ["datetime-parse", "%Y-%m-%dT%H:%M:%S.%fZ", "_T.1utc-time-input"]],
        ["add", "3utc-as-oslo",
            ["datetime-shift", "UTC", "Europe/Oslo", "_T.2utc-parsed"]],
        ["add", "4utc-as-oslo-formatted", 
            ["datetime-format", "%Y-%m-%dT%H:%M:%S.%f", "_T.3utc-as-oslo"]],
        ["add", "5utc-as-oslo-as-string", 
            ["string", "_T.3utc-as-oslo"]]
      ]
    }
  }

A:

No, and this has been improved in later versions of Sesam.  Now you can override the timezone when parsing a timestamp string to avoid the problem:
{
  "_id": "timezone-shift",
  "type": "pipe",
  "source": {
    "type": "embedded",
    "entities": [{
      "_id": "foo",
      "timestamp": "2017-04-12T22:00:00.74Z"
    }]
  },
  "transform": {
    "type": "dtl",
    "rules": {
      "default": [
        ["add", "original",
          ["datetime-parse", "%Y-%m-%dT%H:%M:%S.%fZ", "_S.timestamp"]
        ],
        ["add", "shifted",
          ["datetime-parse", "Europe/Oslo", "%Y-%m-%dT%H:%M:%S.%fZ", "_S.timestamp"]
        ],
        ["add", "original-formatted-as-local-oslo-time",
          ["datetime-format", "Europe/Oslo", "%Y-%m-%dT%H:%M:%S.%f", "_T.original"]
        ],
        ["add", "shifted-formatted-as-local-oslo-time",
          ["datetime-format", "Europe/Oslo", "%Y-%m-%dT%H:%M:%S.%f", "_T.shifted"]
        ],
        ["add", "original-as-string",
          ["string", "_T.original"]
        ],
        ["add", "shifted-as-string",
          ["string", "_T.shifted"]
        ]
      ]
    }
  }
}

Gives the following results:
[
  {
    "_id": "foo",
    "original": "~t2017-04-12T22:00:00.74Z",
    "original-as-string": "2017-04-12T22:00:00.74Z",
    "original-formatted-as-local-oslo-time": "2017-04-13T00:00:00.740000",
    "shifted": "~t2017-04-12T20:00:00.74Z",
    "shifted-as-string": "2017-04-12T20:00:00.74Z",
    "shifted-formatted-as-local-oslo-time": "2017-04-12T22:00:00.740000"
  }
]

