what i learned about live coding at kcdc

This is a post about my experience. For the live blog, see the KCDC 2021 live blog table of contents.

I planned to do 10 minutes of live coding at my KCDC “Intro to JUnit 5” talk. It was an experiment to do more of that in the future. Here’s how it went.

Coding with people watching

This wasn’t as awkward as I worried it might be. I have coded with a bunch of people watching at work before. And I tried mob programming once at an event. I did have to google something I would have been able to copy/paste at work. But that was fine.

My Focus

I’m very interactive when I speak. I watch the audience. I ask them to participate, raise their hands, etc. I look when they look puzzled or their energy level is going down. When my focus and attention are on coding, this isn’t happening.

Why I should have seen this coming

I didn’t enjoy presenting at online conferences because I didn’t get that audience feedback loop. I was ok when on or moderating a panel because I saw the panelists. I’m ok at my team meetings (which to be fair had participants in locations other than mine even before the pandemic) because they are on video.

I did not enjoy presenting to my computer without seeing the audience. And I knew this. It’s why I have been declining opportunities to present at online conferences and meetups. I didn’t connect it to live coding in a room of people. Oh well. Now I know!

[2021 kcdc] space flight in the 2020s

This post is my live blog from KCDC. For more, see the 2021 KCDC live blog TOC

Speaker: Richard Campbell

Twitter: @richcampbell



  • Talked about the billionaires going to space vanity projects
  • Can do freefall for less money
  • New Sheppard went off path and ignored request to go back on track


  • Will launch majority of commercial payloads this year.
  • Drives down price be recovering a stage
  • New contracts incentives traveling often


  • Blue Origin working on Blue Glenn – longer rocket. Nobody has seen anything yet. Like a bigger version of Falcon. But a big jump from New Sheppard.
  • SLS (Space Launch System) attempts to make a rocket out of other parts. Might fly this year. Targets the moon. Congress keeps paying for.
  • Starship (from Elon Musk). Pieces of it exists. Does R&D in public with youtube watching. Bigger than Saturn V, but both stages recoverable


  • In an airplane, 60% is airplane. In spaceship, only 2%. Most is payload and fuel.
  • That’s why it hasn’t been as bad to “fly it once and throw away the airplane”
  • If Starship is successful, reduces cost because fully reusable. Paying for fuel and maintenance. But speculative because doesn’t exist yet. If can do it, costs about the same as a first class airline ticket to go to space.

Space Station

  • ISS (international space station) – mismatch of things. Old. Will end sometime in our lifetime. Originally planned to end in 2020. Now proposals through 2030.
  • Bigalow Aerospace working on inflatable materials to create durable materials and assemble in space. Can connect modules together to build a space station. Three modules would be larger in volume than ISS. Proposed replacing oldest module (Russian one) with inflatable one.
  • Axiom – group of former space station technicians that want to build own space station. Have contract with NASA to build tourism attachments to ISS. Need more money, but raising more.


  • Apollo was a military mission (competition between US and Soviet Union)
  • Were supposed to be 20 missions but cancelled because dangerous
  • Sent one geologist on Apollo 17 (rest military)
  • NASA wants to build an autonomous space station in orbit around the moon.
  • Can’t leave pieces of the craft each time land.
  • Can’t kneel in a space shoot
  • All solutions require some assembly in orbit
  • Margin of error for landings on the moon is 1km.
  • Moon gravity is irregular – up to 2% distortion. (an inch a second faster or slower.) Think based on craters/impact

Problem in space

  • Fluid builds in face because no gravity. Need glasses even if perfect vision because eye shape changes
  • Get weak even if exercise
  • Bottom of feet hurt from lack of use
  • Need centrifuge
  • Need giant centrifuge for 1G because need gravity and feet to be similar so don’t get sick
  • Can do an experiment with extended lower gravity on moon to see what need to travel to Mars
  • Everything to date has been camping trip where bring everything yu need and take everything back with you

My take

This was a fun end to the day! Excellent pictures and stories.

[2021 kcdc] a product approach to tech debt

This post is my live blog from KCDC. For more, see the 2021 KCDC live blog TOC

Speaker: Jennie Ocken


I went to another session first so only saw the second half of this talk.


  • Conway law 
  • Document debt.
  • Decide how much acceptable.
  • Project vs product thinking.
  • Short term thinking.
  • Can deliver quickly if it is less valuable or poor quality. 
  • Three horizons – majority existing market   Next new market if something new for existing market. Then both new 
  • Measure what fire fighting. We reward this culture. Have to thank senior people for working weekend to solve problem. But then juniors think have to. H
  • Hippo. Highest paid persons opinion
  • Objective truth. What are facts. 
  • Debt compounds. 

My take

I missed half, but I liked the half I saw!