The System Builder (ISTP + LSI)

Overview (Introverted Thinking + Sensing)

The System Builder is an individual that is characterized by systematic thinking, logically analyzing whatever they encounter in terms of its logical coherence, rejecting what is logically unsound, and desiring to put anything valuable into a logical framework or system, from which they can “build” and construct a better life or modus operandi. In combination with this logical lens, they possess the drive and physical energy to attain a challenging and worthy future goal.

system: “a set of things working together as parts of a mechanism or an interconnecting network; a complex whole.”

system builder: “A person who builds or constructs a system of any kind. A person who uses system building as a method of construction.”

“A system builder is anyone who assembles, reassembles, or installs software on a new or used computer system.”

Most System Builders are found in professions that either require logical categorization and definitions, mechanics, or that are even more physical and sensorial, such as martial arts, motorcycle racing, stunt work, construction, and the like.

to systematize: arrange according to an organized system; make systematic.

to build-up: assemble or accumulate something by putting parts or material together. make a person or their body stronger.
“if you want to build yourself up you can go to the gym”

Oxford Languages

Purpose Role: The System Builder is in their natural element when they are able to systematically use logical information (esp. related to the sensorial/physical world) based on their understanding and put it into practice by “building up” something or someone.

Main Functions (Ti & Se)

The System Builder sees the world through the lens of what makes logical sense and can be included in their own blueprint of how the world works. Each information is filtered, enhanced, or discarded based on this process. In their minds, everything is either true or false, correct or incorrect. They are in search for the “ultimate truths“ and focused on perfecting them, so as they align in a perfectly symmetrical system or manner. They are not too concerned with the source of the information or its external validity, as long as it “makes sense“ to them, which means it can be categorized into their own logical boxes.

Preferably, The System Builder experiences information in the external world or through varied impressions of whatever they encounter. Some System Builders have boosted energy and desire to be physical, which will make them exert their power and energy, typically through some form of rigorous exercise or pushing themselves. The sensorial inputs deriving from being “in touch“ with the world will be most impressionable and usable for their schematics. Especially so if The System Builder deals with sensorial impressions of technical objects, such as machines, technology, or other kinds of objects and situations that are devoid of emotional context.

Unvalued External Thinking (Te)

System Builders can be rather skeptical and critical of external source material, especially the kind that they deem logically invalid. In that manner, especially if they cannot find scientific evidence, they rather use their “better judgment“ to assess the logical validity. Despite this tendency, they can recall lots of valid external source material as necessary and can periodically engage in extensive research. However, as long as it “makes sense“ to them, they will be inclined to keep using something, and categorize it into a logical box, even if other external information seems to devalue it. 

Admiring External Emotions (Fe)

Despite their proficiency at dealing with primarily inanimate objects/ technical matters and their reserved nature, The System Builder feels a deep draw and yearning for experiencing and exuding strong emotional impact. They tend to be rather withdrawn on a daily basis, but these moments can be interrupted by activities that engage the System Builder physically and emotionally.

At the extreme, they might throw themselves into exuberant parties, emotion-altering drugs or dramatic interactions, followed by a considerable time of recouping; or at the other end they tend to seek out loud music, bustling streets and shops to soak in the emotional atmosphere so that they can “feel something“, be part of the grand emotional sea. Otherwise their internal emotional landscape can be rather empty, sparse, gray and somewhat neutral on its own, not experiencing any particular or definable emotion.

The System Builder requires overt and open displays of emotional moods, such as laughter, frowns, varied voice pitches, in order to feel included, high-spirited, and understand the emotional experience of others. Otherwise, The System Builder can feel stifled and be unintentionally stone-faced, or on the other end brutish and explosive in certain interpersonal situations. Some System Builder can develop some amount of charm as well and come across as (momentarily) sociable. However, this ability is limited and wears them out over time.

Super-Ego: Internal Ethics (Fi)

The System Builder may initially discuss ethical issues and personal preferences of a personable matter, or share their personal judgments of certain people, but this is mostly a means to come across as inclusive and non-robotic.

Aim at Internal Intuition (Ni)

The System Builder strives to use their logical view and physical energy/force to accomplish meaningful goals in the future and grasp deeper meanings. It is commonly a life-long rite of passage for them to develop their future goals, sense of purpose, and to hone their predictive abilities, in some way imitating The Strategist. However, this is not a natural strength, and they primarily rely on their logical capabilities to manage this.

Like the Aesthete, The System Builder gains most of their wisdoms later in life through trial and error phases of risk-taking and sensorial, “tough” experiences.

Weak Intuition (Ne)

Often times The System Builder struggles with assessing abstract potential capabilities, such as strengths and weaknesses, and generating new innovative ideas or concepts. They also tend to grow increasingly uneasy at the sight of different potentialities and being unable to pinpoint one particular outcome, especially in context with other people, which is a sore spot.

Strong Internal Sensing (Si)

The System Builder tends to underestimate their acute internal sensorial experience and capability. Typically they are attuned to the signs of their bodies and how to navigate and nurture them, but they occasionally ignore their inner well-being in favor of external strength. Even so, The System Builder rarely goes too far or pushes their body beyond a certain point, being aware and sensible of its physical limitations. Usually they are well-able at keeping their bodies healthy without too much second thought.

Some System Builder use this awareness in order to correct and improve the physical experience of others, seeing the body as another type of machine or car that requires the correct fuel and treatment. But they do so primarily from the external perspective of improving the physical power or aesthetics of the person, similarly to what some Aesthetes do.

System Builder Celebrities Click here 

Note: Of course there are system builders who possess a different personality type, so please do not assume that all system builders in the world fit this personality type! I call the Introverted Thinking + Sensing personality type “The System Builder” not only because they are usually systematic, but also because this personality structure personifies the archetype the best. The best system builders in the world will have this personality type.

Type Compatibility

Most compatible:

Least compatible: The Pundit

*Note: These types can occasionally be less compatible due to mismatching Enneagram Trifixes.


The Ego of The System Builder

  1. Introverted Thinking (Ti)
  2. Extroverted Sensing (Se)

The Super-Id (valued but weak)

The weakest functions:

The strongest functions:


ISTP (MBTI), LSI (Socionics)

Note: Both MBTI and Socionics include Big 5-related aspects in their types, especially MBTI is mostly a variation of Big 5 nowadays. My version of the Jungian types does not use Big 5 traits, hence the conventional 4-letter idea of “ISTP” might not fully apply. Based on the letters, you might count as “ISTP” but not as The System Builder with Ti and Se as their first functions. Read this for more on this issue.


There are 3 specific subtype variations of The System Builder.

Those variations can be grouped into Ti (Introverted Thinking) subtype, Se (Extroverted Sensing) subtype, and No subtype.

Ti subtype (Classic Introvert)

Ti subtype System Builders share most of those traits:

  • stereotypically introverted
  • more philosophical or reflective
  • less hands-on and forceful
  • more academic or science-inclinations

Can be mistaken for INTP / LII.

Se subtype (Extroverted Introvert / “Ambivert”)

Se subtype System Builders share most of those traits:

  • ”ambiverted” (can be mistaken for an extrovert)
  • more sociable, engaging, and moody
  • higher energy, notably physical and hands-on
  • inclination towards design or the arts, particularly music

Can be mistaken for ESTP, ISFP, ESFP / SLE, ESI, SEE.

No subtype (Standard Type)

A System Builder who falls into both categories more or less is mostly likely the No subtype kind.

Enneagram Type

If you are not Enneagram 6, you are most likely not The System Builder. But make sure you are correctly typed. You can book a Get•Typed session here.


  1. Hi Olimpia,
    I would consider myself an LSI in socionics. You said that LSI’s are usually enneagram 6’s. However i would consider myself an enneagram 1. Certainly, the whole system builder would suit the enneagram 1 personality type as he/she is trying to create order from disorder. What are your thoughts on this?


    • Maybe that works from the Socionics perspective. I am not a fan of the Ij temperament in Socionics, I find it misleading. 1ness mostly correlates best with extraverted judging (Te and Fe), because that actually deals with external structuring and that is the aim of Type 1. Whereas Ti is primarily about internal structures (often mostly for the individual/within the mind), which better fits 6 and 5… hence I would not apply 1ness to “LSI” myself.


      • I watched your video on the subtypes. I consider myself an LSI-Se. Could it be possible for this subtype to be an enn 1 as it is more extraverted than the other Ti sub. Se can be quite bossy at times as well as i”ve seen from personal observation from another LSI-Se. Just a question lol. Thanks for ur reply.


      • Haha I have to say, LSI-Se is even more unlikely for Type 1, because their strongest function is Introverted Sensing, which is an irrational/perceiving function. LSI-Se often has a stronger connection to Type 8. Not saying they are 8s, but they often have a stronger connection to it (fix), due to the Se, so that is what you might associate with “bossy”.


      • Hi Olimpia,
        Thanks for responding. Yeah I forgot about the demonstrative function being the strongest in the contact subtype. Maybe I am an enn 6.

        Liked by 1 person

    • But ultimately, the System Builder is my interpretation of the Jungian Type with the first two functions of Ti and Se, it might differ from other takes of LSI. That is also why I added “ISTP” in the title.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s