Adding notes from Roy Ben Abraham today.

1.2.6. Roy Ben-Abraham <2023-11-22 Wed 10:30>

1. What is your experience with:

1. Low-resource microcontrollers or other hardware facing development?

· Firmware team at Qualcomm (as a student). Microcode, APIs for drivers, writing to registers. Lab experience. 60 GHz wifi hardware.
Insanely complicated power-saving stuff, because of energy constraints.

2. Rust

· Favorite language. 2.5 years working with it. 2 years at a company (replex), real-time data replication across different clouds. Systems stuff. Worked on management layer and data path

3. Automated testing and continuous integration

· Experience dealing with CI. Gitlab and Github and Jenkins. Written some YAML files. Nothing too deep. Not a big fan of test setup and tooling that I don’t really understand. Want to go deep into understanding it. CI workflow is more breadth than depth.

4. Secure system design

· Current job has a lot to do with security, but security has many meanings. (Certora) Smart contracts with formal verification. Actual mathematical proofs for code in production. I worked on dev side of things until recently when I worked with the prover more. Much harder to use the tool than to be the developer of it. Tool might find property true/false or will time-out in many cases. So it’s frustrating to figure out the right rules to write and the long delays in waiting for it to complete. Hard to build an intuition for. Counterexamples the tool yields is also hard to interpret. Kotlin isn’t my favorite though.

2. What is your experience with community-based open source projects?

Wrote some open-source code for Mint layer last company. Rust code for bitcoin layer. Mempool for transactions. PR made to people I worked with on a daily basis.
Not much open-source experience really.
“Really prefer talking to other people about code, not having to guess what they want”

3. Tell me about a scenario where you worked in a multi-stakeholder setting?

Like to resolve conflicts. At Mint layer two people arguing, and both are intelligent, but they aren’t communicating wells. My strength is to listen and try to ask questions to understand viewpoints. Then can dissipate friction. We get emotionally attached to our code, but need to watch out for that.

(What about balancing requirements from people? Imagine memory size versus usability) Big believer in avoiding pre-mature optimization and thinking about documentation. Smart people are dangerous as well as an asset, because you have to interact with other people. You could be holding back people by making things not accessible. Tend to opt for readability.

4. Give an example of a significant project that you completed independently?

Most independent work was Mempool stuff at Mint layer. Not terribly inventive as we started porting Bitcoin mempool to rust. Drew inspiration from there and made code cleaner. Really just me. Lots of unit testing. Had opportunity to architect and refactor things. Most challenging aspect was writing a versatile enough test framework. Testing was more than half the battle. Needed to generate data like real-world scenarios to make sure validations are “real”. Needed to be creative to cover code paths. Didn’t want randomness in unit tests, wanted stability and coverage. Eventually integrated with system, which became a collaboration.

5. When is a project “done”?

For mempool, I never was. Covered the basics and a lot of little edge cases and code to protect against vulnerabilities that I never got to the bottom of and were deferred to later. There was a point where I had an API that could interact with other parts of the system. Once you have the framework, and that’s the hardest part, the code at that point is largely rote. Time constraints from the rest of the company lead to moving on.

(What about an experience without a time limit?) Worked on a visualization for gas drilling. Tons of bugs coming in, with limited knowledge of the entire system. Turned into a best-effort thing where some bugs are solved and some aren’t. There was no deadline, it was just whatever we could fix.

Similarly, studies in my own time. JohnYancit does long Rust streams with big videos.

6. Do you have experience working with remote collaborators?

Experience at Mint layer. Didn’t think about remote work before COVID. Mint layer was my only fully-remote job. Advantages and disadvantages. On-boarding is daunting, especially for a field you’re not familiar with. Didn’t know blockchain coming in. Biggest qualm was having daily meetings over slack without video. This meant I was working months with people and didn’t see them. Felt alienating. It wasn’t a good environment due to lack of personal connection. I always try to encourage people to turn on video for the human connection.

7. How often do you prefer to check-in with stakeholders on your project?

No regular clock for check-ins. If someone is giving me requirements, I do want availability from them though. I don’t want to have to guess about it. So if something isn’t clear, then I want to check in.

Long-drawn out code reviews drive me mad. Not sure when they’re done reviewing. Lots of context switching, big toll on me.

I don’t think “daily” meetings are necessary. Can be a big waste of time. But it’s crucial that there is a channel of communication. Some aspects of software should be synchronous.

8. What is your preferred mode of working in a group?

(Got this already from the above. Really wants the in-person connection, even when remote. Wants channels of communication so not guessing about things.)

9. What challenges do you foresee on-boarding to working on Tock in this role?

Understanding the full scope of what it means to have security considerations. Some subtlety there. Don’t have great intuition for what makes code secure or not. Not much experience yet. Pretty good aesthetic taste, but thinking across sections of many things going wrong is a challenge. Starting to develop it at my current job as I have served in many roles. As opposed to embedded and rust, where things feel more comfortable.

On Wed, Nov 15, 2023 at 12:16 PM Amit Levy via Pose <pose@lists.tockos.org> wrote:

First Name Last Name E-mail Round 1

Walter Smuts smuts.walter@gmail.com <2023-11-10 Fri 10:30>

Gabriel Leupin leuping@gmail.com <2023-11-10 Fri 13:30>

Gregory Terzian gregory.terzian@gmail.com <2023-11-13 Mon 10:30>

Justin Frevert justinfrevert@gmail.com <2023-11-13 Mon 13:30>

Sean Cross sean@xobs.io <2023-11-15 Wed 09:30>

Roy Ben-Abraham roy.ben.abraham@gmail.com <2023-11-22 Wed 10:30>

1. Round 1 interviews

1.1. Questions

1.1.1. What is your experience with:

Low-resource microcontrollers or other hardware facing development?
Rust
Automated testing and continuous integration
Secure system design

1.1.2. What is your experience with community-based open source projects?

1.1.3. Tell me about a scenario where you worked in a multi-stakeholder setting? E.g. one where different contributors had different incentives and resources? Or, what strengths do you bring to this environment and what challenges might you face?

1.1.4. Give an example of a significant project that you completed independently?

How long was the project?

How much did you rely on guidance from others (e.g. a client, manager, advisor, mentor, etc)?

How did you gather feedback from others?

Did you discover the design or requirements changed as you progressed in the project? Why? How did you handle that?

1.1.5. When is a project “done”?

1.1.6. Do you have experience working with remote collaborators?

1.1.7. How often do you prefer to check-in with stakeholders on your project?

1.1.8. What is your preferred mode of working in a group?

1.2. Notes

1.2.1. Walter Smuts <2023-11-10 Fri 10:30>

What is your experience with:

Low-resource microcontrollers or other hardware facing development?

Microcontroller project on a motorcycle, calculate speed, calculate fuel efficiency
Undergraduate in electrical and computer engineering
STM discovery board modulator

Rust

Memory manager for Brimstone in Rust
Written partial pitch corrector, etc, music stuff, chess server
Excited about the type system
Maintainer of two crates on crates.io
Lots of performance and memory sensitive related operations

Automated testing and continuous integration

Always be sure that tests pass
Big fan of CI and automated testing

Secure system design

Low-level experience on the Brimstone hypervisor. Memory over-subscription.

Forces to think about security + hardware

What is your experience with community-based open source projects?

Open source crates
Contributed to a bunch of projects

RustFFT etc
Sub-array
Array init

Rust project

Posted two pre-RFCs

Generic statics
Type inference on generic defaults

LMMS
Val/Hilo programming language
Amazon pushed to Linux from his team (capmem)

Tell me about a scenario where you worked in a multi-stakeholder setting? E.g. one where different contributors had different incentives and resources? Or, what strengths do you bring to this environment and what challenges might you face?

Teams at AWS are very independent

Upper level managers don’t really set agenda
Teams fight and haggle
Typically: great idea, there isn’t capacity to work on in internally
Still burden of review

Give an example of a significant project that you completed independently?

How long was the project?
How much did you rely on guidance from others (e.g. a client, manager, advisor, mentor, etc)?
How did you gather feedback from others?
Did you discover the design or requirements changed as you progressed in the project? Why? How did you handle that?

When is a project “done”?

What do you define as a project? Design it, get consensus on design, get merged, only after gained experience in the wild.

Do you have experience working with remote collaborators?

EC2 in Cape Town does much of the control plane work. Generally don’t work on the hypervisor. Collaborated much with the Dresden and Seattle team.

None of that in person
Way more asynchronous work

Stand up meetings for local team

One member of team at 11pm

For the past year, freelancing for async clients

How often do you prefer to check-in with stakeholders on your project?

As often as needed

What is your preferred mode of working in a group?

What challenges do you foresee on-boarding to working on Tock in this role?

Tend to be best where I understand the goal of the system

But its the best way to approach things
Others tend to thrive better in the land in the unknown
Ways to make progress involve understanding the low-hanging fruit
Want to get dividends payed out from the start

1.2.2. Gabriel Leupin <2023-11-10 Fri 13:30>

What is your experience with:

Low-resource microcontrollers or other hardware facing development?

At Mercedes worked with on-board CPUs, consumers of output of CPU
Noticed issues with C++

Rust

Have been working in Rust for a couple years
Mostly in distributed systems
Big fan of memory safety

Automated testing and continuous integration

Jenkins
Made a small deployment engine recently
Limited experience with CI

Secure system design

Primarily as a user of secure systems, mostly authentication patterns

What is your experience with community-based open source projects?

Used Open Telemetry, project with SIGs etc

Tell me about a scenario where you worked in a multi-stakeholder setting?

Mercerdes “internally open source”

Responsible for reviewing PRs from the team in India
Interfacing with many teams around the world
Logging is a critical component

Entirety of the company underwent a transition, delayed by years

Logger became a more unified framework
Competing interests with what made sense to do
A lot of meetings, a lot of understanding of the core technology details

Give an example of a significant project that you completed independently?

Education startup building a search engine

Planful Learning and Assessment
Took on a lead role of the search engine and model based on Netflix recommendation engine. Human in the loop + extensible

When is a project “done”?

When its suited for its primary use case
Have a test for the first big use case

Do you have experience working with remote collaborators?

Much of the work since the pandemic has been remote

Daily standups with team
Meetings at times for different time-zones

Hybrid might be favorite
Like meetings over async

How often do you prefer to check-in with stakeholders on your project?

Balance to be struck between be able to think through yourself and unknown time-bound

But asking to many questions of other people
Early on helps to ask a lot, then show testimony you’ve learned from what you’ve said

Planful

Early on met a lot
As soon as spec was set, very self directed

A few weeks or months mostly independently

What is your preferred mode of working in a group?

Very comfortable working in a group

Good to be professional

Mercedes, work was pretty isolated

Would wait asynchronously
Pleasant though sometimes aggravating

Ed startup was more free-for-all

Liked both

What challenges do you foresee on-boarding to working on Tock in this role?

Learning curve
Majority of company at Mercedes was German

Most people in office were native German

1.2.3. Gregory Terzian <2023-11-13 Mon 10:30>

What is your experience with:

Rust

Servo work very relevant
Started working with Rust on Servo

Low-resource microcontrollers or other hardware facing development?

No experience

Automated testing and continuous integration

Used it a lot, almost every project has something set up
Servo had more of a bespoke thing
Not too involved with the design of the systems
But used them extensively
Empathy for dealing with one, especially in an open source context

Smoke tests vs actual test run

Secure system design

Tock design reminiscent of browser
Good understanding of background for the need for processes isolation in browsers
Worked in the blockchain space in Rust

A bit ambivalent now
Opportunity to work in Rust professional
Very specific kind of distributed system
Various systems in Byzantine settings

What is your experience with community-based open source projects?

Most notably Servo

Largest in terms developer community
Largest in size of code base

Automerge, CRDT, sponsored by a different company

Wanted to solve a particular problem
Small project with limited budget, with particular goal for a sponsor
Library would be nonetheless should contribute to the ecosystem around automerge

Servo

Many of the Mozilla employees working on it because Mozilla wanted them to work on it
Mozilla focused more on pet-projects, e.g. VR, not the web standards

Also ended up working with standards “bodies”, e.g. the common test suite

Work within the constraints of standards

Tell me about a scenario where you worked in a multi-stakeholder setting?

Before time in Rust, in Python, hired by company for grant matching tool

Mostly organizational challenges: e.g. conflicts between sales and engineering, such as where to post. CEO and Sales had conflicts

Experience with open source has been looser

Give an example of a significant project that you completed independently?

Automerge project:

Had a JavaScript implementation already
But would do it differently than in Rust

A bit of figuring out what we wanted to do

Initially talked quite a bit (a couple times a week)
Then work on my own for a few days, then discuss

With Servo just picked an issue to work on

Some projects would take months
Could ask for early feedback, but mostly independently working on the work
Had to communicate issues with initial agreed designs given the details

When is a project “done”?

Sometimes the money runs out
For example, on Servo, time not an issue

At some point, e.g., how much can we get the test suite to pass?

Do you have experience working with remote collaborators?

Most of work is remote

How often do you prefer to check-in with stakeholders on your project?

Depends:

If working with people on code or some artifact, then on daily basis
Otherwise can be more like once a week, maybe for more social reasons
For stakeholders, really depends

Mozilla “meet-up” meetings in person were great
Video conference calls maybe once in a while

What is your preferred mode of working in a group?

Like to have time on my own every day

Need to have a block of time

Also to need to get feedback on output
Some social interaction is also important

E.g. chat
Video chat
But for social

E.g. Chromium has guidelines about how quickly you need to answer questions

What challenges do you foresee on-boarding to working on Tock in this role?

Building testing infrastructure is new
Integrating with the team may not be easy
Hardware oriented software development

1.2.4. Justin Frevert <2023-11-13 Mon 13:30>

What is your experience with:

Low-resource microcontrollers or other hardware facing development?

None

Rust

Working in Rust for ~2 years

Mostly stuff that compiles in no_std and in WASM
No multi-threading
No heavy lifetime stuff

100% Rust
Came into it through Blockchain

Wanted to build protocol that would marry interests in media & finality
Started learning Rust around a particular project

Automated testing and continuous integration

Worked with GitHub actions and AWS services along the same lines

Just specifying the YAML automation for the pipelines

Secure system design

Alot of work around blockchains involve security considerations

Much work done in adversarial environment
Might need to worry about possible vulnerabilities of code

Example: staking protocol at FUTUREVERSE

Could see that people could influence the speed at which something could run
Opted for deterministic computation

What is your experience with community-based open source projects?

Have worked entirely in open source projects

RISC-ZERO, a risc-v based virtual machine, execution backed by a zero-knowledge proof
some contributions to other projects

Tell me about a scenario where you worked in a multi-stakeholder setting?

Most recent role at FUTUREVERSE, on a team building a Rust/WASM stack

Management was used to apps that could iterate in very fast cycles
Developers (me) didn’t necessarily agree with methodology
Spent a lot of time pushing for more quality procedures
Was able to push for another week

Give an example of a significant project that you completed independently?

Pretty interested in properties of polynomial commitments
Built a fully implemented KZG commitment scheme

When is a project “done”?

Depends
For something like KZG, the state where the library can compute

Do you have experience working with remote collaborators?

Mostly remote work in the last few positions

How often do you prefer to check-in with stakeholders on your project?

Roughly weekly check-ins
+ semi-asynchronous environment
Written communication in particular

What is your preferred mode of working in a group?

Strong written communications, appreciate detailed PRs/issues/etc, as well as a chat
Periodic calls (e.g. one or twice a week)

What challenges do you foresee on-boarding to working on Tock in this role?

Lack of foundation in microcontrollers and systems

Ask for quick resources
Have to do pretty broad research
Don’t necessarily know the terms to look into

Could improve on CI & testing, never had a role that focused on it

1.2.5. Sean Cross <2023-11-15 Wed 09:30>

What is your experience with:

Low-resource microcontrollers or other hardware facing development?

Automated test & CI

Love-to-code, 32kB flash and 4kB of RAM

Demodulated over-the-air programs
Created an opcode-based thunk-system

Done a lot of hardware products

All requires a factory test that runs on the actual hardware
Difference between factory and CI: testing for did all the connections get made

Very important: always ask “what are we testing”
In factory, testing resoldering, e.g.

Renode for hardware testing

Use a bunch of embedded operating system development

Rust

Mostly delt with building the libstd world

Have some platform code that is upstream in Rust
libstd support for Xeus upstream

No specific experience in embedded development in Rust

Nightly support
ufmt

Secure system design

Operating system development

Work on Xous

Security: can request a physical area of memory
Used on two platforms

precusor platform (RISC-V based smartphone)
Foundation OS

What is your experience with community-based open source projects?

Have contributed code to Linux

Lots on minutia to get it just right
A little bit too draining

Gotten things merged in Rust

Fastest is 10 minutes
Slowest is 1.5 years

Have to be patient
Other community-based OS projects:

Drive by patches on GitHub all the time
Big fan of making things as easy to build as possible

Making it simple for development platforms as well

Black magic project

Tell me about a scenario where you worked in a multi-stakeholder setting?

Unwinding support in Rust

Rather invasive and platform-specific process
Turns out much of the patching for LLVM in Rust is for SGX
Had to re-assure that this won’t remove LLVM’s unwinding

Give an example of a significant project that you completed independently?

When is a project “done”?

“How do you finish a project”

Minimum amount of functionality, at least MVP

For fooboot, e.g., had planned for a secondary platform, but never did it, because people weren’t using it that way

For firmware, it’s done once it ships (?)
“Trying to lower the bus factor”

Do you have experience working with remote collaborators?

In open source
Much of the work is remote

How often do you prefer to check-in with stakeholders on your project?

Usually weekly is a good cadence for checking in with people

What is your preferred mode of working in a group?

Like to batch things up and have questions combined

So quarterly or half-yearly meetings
Conferences are great

When working on a module, a video can be helpful

E.g. for deeply embedded keyfob
Maybe every couple of days
Being in a chat

What challenges do you foresee on-boarding to working on Tock in this role?

1.2.6. Roy Ben-Abraham <2023-11-22 Wed 10:30>

What is your experience with:

Low-resource microcontrollers or other hardware facing development?

Rust

Automated testing and continuous integration

Secure system design

What is your experience with community-based open source projects?

Tell me about a scenario where you worked in a multi-stakeholder setting?

Give an example of a significant project that you completed independently?

When is a project “done”?

Do you have experience working with remote collaborators?

How often do you prefer to check-in with stakeholders on your project?

What is your preferred mode of working in a group?

What challenges do you foresee on-boarding to working on Tock in this role?

First Name	Last Name	E-mail	Round 1
Walter	Smuts	smuts.walter@gmail.com	<2023-11-10 Fri 10:30>
Gabriel	Leupin	leuping@gmail.com	<2023-11-10 Fri 13:30>
Gregory	Terzian	gregory.terzian@gmail.com	<2023-11-13 Mon 10:30>
Justin	Frevert	justinfrevert@gmail.com	<2023-11-13 Mon 13:30>
Sean	Cross	sean@xobs.io	<2023-11-15 Wed 09:30>
Roy	Ben-Abraham	roy.ben.abraham@gmail.com	<2023-11-22 Wed 10:30>