expertise: Y I trust lecture notes more than forums

Q: A lot of times we get technical information in forums, online lecture notes, research papers. why do I trust some more than others?

  1. printed books and magazines — receive the most scrutiny because once printed, mistakes are harder to correct. Due to this fundamental reason, there is usually more scrutiny.
  2. research papers — receive a lot of expert peer review and most stringent editorial scrutiny, esp. in a top journal and top conference
  3. college lecture notes — are more “serious” than forums,
    • mostly due to the consequence of misinforming students.
    • When deciding what to include in lecture notes, many professors are conservative and prudent when adding less established, less proven research findings. The professor may mention those findings verbally but more prudent about her posted lecture notes.
    • research students ask lots of curious questions and serve as a semi-professional scrutiny of the lecture notes
    • lecture notes are usually written by PhD holders
  4. Stackoverlow and Quora — have a quality control via voting by accredited members.
  5.  the average forum — Least reliable.
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impostor’s syndrome: IV^on-the-job

I feel like impostor more on the job than in interviews. I have strong QQ (+ some zbs) knowledge during interviews. I feel it more and more often in my c++ in addition to java interviews.

Impostor’s syndrome is all about benchmarking. In job interviews, I sometimes come up stronger than the interviewers, esp. with QQ topics, so I sometimes feel the interviewer is the impostor !

In my technical discussions with colleagues, I also feel like an expert. So I probably make them feel like impostors.

So far, all of the above “expert exchanges” are devoid of any locaySys. When the context is a localSys, I have basically zero advantage.  I often feel the impostor’s syndrome because I probably oversold during interview and set up sky-high expectations.

##[19] am competent at..as a professional thanks2tsn

Background — When I listen to a professional musician or comedian from some unfamiliar country, I wonder if they are actually good. Similarly, when I consult a doctor or dentist, I wonder if they are qualified.

“Self-respecting programmer” — Yi Hai’s motivation.

I have been tested and proven on the big stage i.e. U.S. tech interviews + GTD

  • [p t w] java/c++/c#
  • [w] algo
  • [w] coding test
  • [t] SQL
  • [t] socket
  • [t] unix power user
  • swing
  • [p] web app developer across php, javascript, java
  • py, perl (and shell/javascript?) — are these professional games?
  • [t = long tradition over 20Y]
  • [w = worldwide contest]
  • [p = a well-known standard profession]

##[15] I do professionally qualify as …

See also ##[19] am competent at..as a professional

See also blogpost on “N years’ experience — unimportant” and #1 career safety enhancer@past5years

On Wall St there are “combo” jobs to my advantage, but unheard of in SG.

I can qualify as :

became expert via external QQ benchmark` !!localSys xx

Suppose I invest heavily and become very productive on a local c++system. Similarly, a java, or SQL, or socket, pyhton .. system, but the point is — Any local system uses only a small portion of the language features.. at most 5% of the typical high-end interview topics on that language.

Therefore the project experience won’t give me confidence to be an expert on the language, but acing multiple QQ interviews does, as these interviews compare dozens of competitive, motivated and qualified candidates across a wide field.

I grew very confident of java through this type of external benchmarking, in contrast to internal benchmarking within the local team.

low-level^high-level expertise

See also my blogpost on wrapper^low-level API

Compare to laymen on the street, I have accumulated fairly deep, specific and demonstrable non-local expertise in two lucrative field i.e. software dev + finance

  • concurrency details (theory++) in real languages
  • dStruct choices and effective combinations
  • dStruct implementation details in java/c++/pyhton
  • SQL joins and tuning
  • sockets? no deep insight but my expertise beats most peers
  • Most standard algo problems are familiar to me
  • memory models, memory layout.. beneath c++ and java
  • drv pricing math, VaR statistics, bond math. My expertise goes beyond the degree

These trophies are won based on TSN, interviews and personal time investment … not automatically

— Let me focus on low-level vs high-level
Most of the dev expertise domains are low-level, consequently very specific — you either know it or don’t. I can even teach in these subjects. The more low-level, the rarer is the expertise. The laymen developers have a vague idea of the low-level details, for many reasons.

High-level understanding is often more useful (than low-level, theoretical QQ knowledge) in projects, but in job interviews, low-level knowledge is differentiator.

Practically all (98%) high-end java/c++ interviews use low-level questions as differentiator. I excluded the start-ups as I’m unfamiliar with them… Eg: Quoine.

In my dev (not system architect) interviews, they rarely asked high-level stuff like spring rationale, design patterns…
I tend to believe these questions can’t /separate the crop from the chaff/

The finance dnlg  also serves as differentiator among developers. The most specific sub-domains are quant math, the “architecture” and some of the jargon.

C++ is more low-level than java; java is more low-level than python…

Q: Paradoxically, C and assembly are even more low-level but not more valuable?
%%A: Some C knowledge is highly valued. For example, kernel knowledge is high-value and mostly at the level of C, compiler, assembly, and hardware
%%A: assembly expertise in device drivers or embedded is not really relevant to HFT, and too far from the money

MOM is not low-level and seldom asked.

fellow experts siz`up each other≈ QQ IV

  • Scenario — Female engineer at an electronics exhibition booth, in the 70’s.
  • Scenario — a passenger falls sick on a flight and two doctors (different countries) came to the rescue. They size up each other to decide who to take the lead.
  • Scenario — two musicians across genres play together impromptu for the first time. Musicians usually are cooperative not competitive though.
  • Scenario — a comp science student visits another campus and logs in on the local network and start exploring (not “hacking”) and encounters local students on the network.
  • Scenario — provincial basketball player coming to a new town and plays a first one-on-one game with a top local player.
  • Scenario — an interesting algo challenge is openly discussed, among programmers from different countries and across industries. A problem to be solved in any language without external tools.

These scenarios are similar to QQ interviews. (Algo interviews are subtly different but mostly similar.) Venkat of OC impressed me with his c++ and c# QQ knowledge.

When fellow experts size up each other … what acid tests can they use? Algo, QQ topics or ZZ topics (I tend to read in my spare time)?

To really size up each other, we need to discuss common topics, not Your or My localsys.

.. but many people only talk about, in vague or high-level terms, how some localSystems were supposed to work, often based on hearsay. They leave out the important details. It’s impossible to verify any of those claims.

When we watch a movie from Europe, India, Korea … we can tell whether it has any international appeal or only limited local audience.  Similarly localSys knowledge has value only within a single company. The expertise I demonstrate in job interviews are relevant across many sites.

If I were a 5Y VP (or ED) I would have self-doubt — am I just a localSys expert or an accredited expert as proven on benchmarks/interviews? Look at Shubin/Steve, the Sprite expert in London, Richard of Quoine ..
Their expertise and value-add can be marginalized in the context of the current mainstream technologies.

c++QQ critical-mass[def2] has started growing!

If I compare myself with young c++ developers or older guys (like CSY, Paul..) I can see clear patterns in QQ and GTD.

  1. QQ and (to a lesser extent) zbs — I’m clearly pulling ahead, sometimes heads and shoulders above them. Some of these guys have wider QQ knowledge but lacks depth. I wrote about “experts” sizing up each other..
  2. zbs: instrumentation — one of the key areas of improvement for me! However, I can see many of the older guys at RTS aren’t more knowledgeable.
  3. GTD: paradoxically, the younger guys are more productive than me or older guys.

— Now let’s retrace the gradual breakthrough

In May 2019, I felt I have achieved enough critical-mass on c++ QQ topics. Critical mass is defined by The two acid test questions.

Q1: without a full-time c++ job, but with enough interviews, will my c++ QQ insight/understanding show resilience against churn and memory fading, as in coreJava?
Q2: thick->thin achieved? Not yet, but cross-reference graph is now built up as a defense against fading memory

This java career review provides a valuable context.

What visible progress gave me this level confidence? Recent technical wins show my improved ranking among c++candidates.

  1. SCB-FM
  2. CVA
  3. SIG
  4. TradeWeb core team

Note I have invested more effort on c++ QQ than java… [18]t-investment: c++now surpassing java

  • — now a sample of critical-mass topics, roughly ranked by importance on high-end interviews, mostly at HFT and ibanks
  • coding tests
  • mv-semantics
  • containers
  • smart ptr
  • heap memory mgmt including new..
  • polymorphism including MI #44 posts in the category
  • TMP — important at high-end but not HFT
  • [e] pthreads + c++11 threads
  • [e] sockets
  • runtime costs of virtual and heap, as Stroustrup explained
  • [e] cache efficiency, compiler optimizations,
  • [e] linux
  • [e] new innovation directions
  • [e] benchmarks involving c++ as Stroustrup explained
  • build tools
  • [e=ecosystem topics]

long-term value: QQ imt ECT speed

The alpha geeks — authors, experts, open source contributors … are they fast enough to win those coding contests?

The speed-coding contest winners … are they powerful, influential, innovative, creative, insightful? Their IQ? Not necessarily high, but they are nobody if not superfast.

The QQ knowledge is, by definition, not needed on projects, usually obscure, deep, theoretical or advanced technical knowledge. As such, QQ knowledge has some value, arguably more than the ECT speed.

Some say a self-respecting programmer need some of this QQ expertise.

denigrate%%intellectual strength #ChengShi

I have a real self-esteem problem as I tend to belittle my theoretical and low-level technical strength. CHENG, Shi was the first to point out “你就是比别人强”.

  • eg: my grasp of middle-school physics was #1 strongest across my entire school (a top Beijing middle school) but I often told myself that math was more valuable and more important
  • eg: my core-java and c++ knowledge (QQ++) is stronger than most candidates (largely due to absorbency++) but i often say that project GTD is more relevant. Actually, to a technical expert, knowledge is more important than GTD.
  • eg: I gave my dad an illustration — medical professor vs GP. The Professor has more knowledge but GP is more productive at treating “common” cases. Who is a more trusted expert?
  • How about pure algo? I’m rated “A-” stronger than most, but pure algo has far lower practical value than low-level or theoretical knowledge. Well, this skill is highly sought-after by many world-leading employers.
    • Q: Do you dismiss pure algo expertise as worthless?
  • How about quant expertise? Most of the math has limited and questionable practical value, though the quants are smart individuals.

Nowadays I routinely trivialize my academic strength/trec relative to my sister’s professional success. To be fair, I should say my success was more admirable if measured against an objective standard.

Q: do you feel any IQ-measured intelligence is overvalued?

Q: do you feel anything intellectual (including everything theoretical) is overvalued?

Q: do you feel entire engineering education is too theoretical and overvalued? This system has evolved for a century in all successful nations.

The merit-based immigration process focus on expertise. Teaching positions require expertise. When laymen know you are a professional they expect you to have expertise. What kind of knowledge? Not GTD but published body of jargon and “bookish” knowledge based on verifiable facts.

##af 70 ..spend%%spare time meaningfully

Holy grail — Long-term sustainable (hopefully intrinsic) motivation + modest level of expertise, with reliable (albeit low) income and (a bit of) social value.

I need a purpose, a goal to work towards… Without it, the absence of a … job would create a void. Depression, lack of purpose, loss of energy. None of the below is easily achievable or easily available. Whichever I choose, need to work towards it.

  • Research would be ideal. I have proven aptitude in theoretical domains ..
  • xp: I think the RTS/NYSE work has more meaning as it impacts more users.
  • xp: devops effort has proven value to the local team
  • I might consider joining a start-up, which provides employment and learning opportunity for younger workers (perhaps in their 50’s?)
  • Teach (online) — Chinese/English, with emphasis on writing and vocab
  • Teach (online) — programming? threading, data struct, algo
  • Teach — statistical data analysis, If not outdated..
  • Teach — enterprise app design, If not outdated? Too competitive. They may not take in an old programmer.
  • Teach — financial math? After 70?
    • ▼this domain is too competitive and entry barrier too high. A lot of effort to cross it but demand is low.
    • ▼Limited practical value. more specialized, but growing demand.
    • ▼I feel I need interaction with people.
  • Two-way translation service, but I prefer interactions.
  • Chinese medicine?

Tim (RTS), a friend in his 50’s gave 3 points

  1. earn a salary to help kids pay student loan
  2. sight seeing world wide — costs a lot
  3. volunteering

2 pitfalls on my accu path #portable,MktDepth..

Say you stay in one team for 5 years, hoping to accumulate expertise and insight

  • Trap 1: local system knowledge, 100% nonportable
    • eg: Qz
    • Tibrv wrappers in 95G is not so bad
  • Trap 1b: limited standardization across companies.
    • eg: cryptocurrency
    • eg: OMS framework? M b2bTradigEngine ^ SIG ^ ETSFlow
    • eg: software mkt data dissemination cf raw mkt data parsing
  • Trap 2 : poor market depth
    • eg: vol fitter

algo-IV^QQ expertise

Background — became expert via external QQ benchmark` !!localSys xx

Q2: how are algo quizzes different from the C++ language expertise tested in job inerviews?
%%A2: I feel this algo expertise is loosely defined — mostly defined by a few hundred “fashionable and common algo interview questions.”

Ironically, the algorithm researchers and inventors may not ace these west-coast algo interviews 😉 Also, the non-trivial algorithms in textbooks are invariably too complicated for a 45-min coding interview.

There’s no deep insight or innovation in this game. This type of “expertise” doesn’t solve tough real-world problems. They can only solve simple real-world problems.

Top performers in this game are possibly students, exam-taking machines. They won’t feel proud of themselves as compared to c++ language expert or algorithm inventor.

Q2b: how are speed coding different?
%%A: in addition to A2, speed coding requires a mastery of a tiny subset of the language features and mastery of many coding idioms based thereon.

c++QQ/zbs Expertise: I got some

As stated repeatedly, c++ is the most complicated and biggest language used in industry, at least in terms of syntax (tooManyVariations) and QQ topics. Well, I have impressed many expert interviewers on my core-c++ language insight.

That means I must have some expertise in c++ QQ topics. For my c++ zbs growth, see separate blog posts.

Note socket, shared mem … are c++ ecosystem, like OS libraries.

Deepak, Shanyou, Dilip .. are not necessarily stronger. They know some c++ sub-domains better, and I know some c++ sub-domains better, in both QQ and zbs.

–Now some of the topics to motivate myself to study

  • malloc and relatives … internals
  • enable_if
  • email discussion with CSY on temp obj
  • UDP functions

y at this age still !! an expert like Dad@@

At this (or later) age, perhaps Dad was already able to publish valuable information for his research community?

Look at my perl experience.

Look at SGQ. Accummulated dnlg but …
Look at QLN. So many years on SAP cap planning/tuning but perhaps his job scope only gave him routine techniques. Perhaps someone with 1 year training can achieve the same mastery.

Maybe we need to join a cutting-edge dev team in a big co or an open-source team?
Maybe we need to publish.
Maybe we need to present papers in conferences.