TIL Blog

Node.js Callback Queues

2020-07-09T00:00:00+00:00

Learned some about Node.js internals and Callback Queues in particular. It appeared Node.js maintains multiple prioritized queues to handle callbacks.

Call Stack - keeps track of the function currently being executed and of its origin. Event Loop - responsible for code execution. Callback Queues - hold callback functions of completed asynchronous operations.

In order of priority

Microtask queue - process.nextTick, Promise 
Timer queue - setTimeout, setInterval 
IO queue - file system, network 
Check queue - setImmediate 
Close queue - closing HTTP connection, stream, etc

Links

A deep dive into queues in Node.js

Coaching vs Mentorship

2020-07-06T00:00:00+00:00

Clarified the two terms for myself.

Mentorship - a relationship between an experienced person and someone who wants to grow. Mentee is defining measurable goals and execute on the plan. Mentor is helping with advice, guidance, suggestions, support. Both review and measure the progress.

Coaching - is helping people to help themselves. No guidance, “ask, don’t tell”. Coach helps coachee to recognize areas of development, to reflect, to challenge themselves, and to be accountable.

Both relationships have common grounds such as identifying strengths and weaknesses, visualizing the desired future, and identifying goals.

Coaching is more abstract and less guided. Coach doesn’t have to be more experienced in the target area than the coachee.

Links

Tech Lead vs EM

2020-06-23T00:00:00+00:00

I had some sense of those terms, and today one article made it clear

Tech Lead - leading a team and aligning technical direction. Architecture, code quality, tools, coaching, influencing, delegation.

Team Lead - focuses on team issues, provides personal feedback, 1-1s, career development, cross-teams communication, team processes, managing stakeholders, and risks.

Engineering Manager - a high level Team Lead, maintaining productive environment, budgeting, communicating on management level, recruiting, org processes.

Links

Career Planning

2020-06-15T00:00:00+00:00

Career planning is an extremely important process that should be formalized and documented.

With a clear career path within the organization, it is a way easier to talk with people about growth and skills development.

But even with no grades and levels defined, it is still valuable to base upon generic terms like jr, middle, senior, etc.

Clear Expectations

2020-06-11T00:00:00+00:00

Once again I convinced myself in the importance of clear expectations. Any inaccuracy in task description could lead to a bunch of time spent on clarifications. Nevertheless, it is fulfilling when you finally managed to convey the truth.

Single Table Design

2020-05-29T00:00:00+00:00

Working mostly with relational databases it is fascinating and eyes-opening to learn about DynamoDB Single Table Design.

DynamoDB tables consist of keys and attributes. What is interesting is that keys and attributes do not have to be homogenous, means it is possible to store absolutely different records in the same DB and sucessfully operate that structure.

Primary key - is a partition key OR partition + sort keys

Partition key - a top-level primary identifier. The data would be split by that key

Sort key - used for sorting and querying. Could be composed from multiple values and queried by prefixes.

Secondary index (local, global) - allows additional querying scenarios. Local - with the same partition key as the original table.

Single Table Design

The main reason for using a single table in DynamoDB is to retrieve multiple, heterogenous item types using a single request.

Links

Clean Architecture Terms

2020-05-22T00:00:00+00:00

I’ve heard those terms multiple times but never actually thought about their origin or proper use.

Researching class naming conventions and concerns separation I found references to Clean Architecture book by Robert C. Martin.

Listing the terms I’ve selected to introduce for the Team

Model (Entity, Aggregate) - a representation of a business entity. Encapsulates associated business logic. Typically responsible for persistence.
Domain Service (Interactor) - domain logic that relies on two or more entities.
Use Case (Application Service) - a list of actions or event steps typically defining the interactions between a User and a system to achieve a goal.
Gateway - an adapter between the application and a 3rd party API.

Links

Node.js streams

2020-05-21T00:00:00+00:00

TIL that Node.js streams could be extremely useful when you need to process a paginated API and batch or just consume it in a functional fashion.

await pipeline(
  fetchRecords,
  JSONParser,
  changeDateFormat,
  queueBatch(queueUrl)
)

Links

Node.js streams documentation

Thinking about your thoughts

2020-05-19T00:00:00+00:00

TIL that meditations allow you to be aware of and to think about your thoughts while those whirl in your mind. That’s a phenomenal notion and something I never wondered about.

Product Teams

2020-05-15T00:00:00+00:00

I stumbled upon an interesting opinion about an engineering team’s organization. I’ve never looked from that perspective and never worked in an “empowered product team” 😄

Product Teams

Characteristics

Cross-functional
Measured by outcomes
Empowered to solve the problems

The Team purpose: to solve problems in ways our customers love, yet work for our business.

Feature Teams

The Team purpose: to implement items of a prioritized list (roadmap, backlog, etc).

Key differences

in PT, the product manager is responsible for the value and viability risks
in FT, the stakeholders are responsible for the value and viability risks
in FT, the product manager is a facilitator (a project manager)

Links