## Passion for System Design

After finishing a one year project, my longest stable team (lasted for 3 years) was separated into two smaller teams. Sadly, but that was a good chance for me to become a key member in my new team. My preferred skills were about system architectures; therefore most of the tasks of building the application structures were handled by me. In order to enhance my design system skills, I have spent much my time for reading books closely after work. These following books help me a lot.
- Object-Oriented Thought Process | Matt Weisfeld
- Head First Design Pattern | Elisabeth Freeman and Kathy Sierra
- Java 8 in Action: Lambdas, Streams, and Functional-style Programming | Alan Mycroft and Mario Fusco

## Junior Technical Architect

I was requested to join a technical architect team (aka Team. Alpha) where I actually had gained experiences almost on interviewing candidates for my company (lol). Besides, I noticed myself must improve the skills of convincing people because I had had a strong debate with other members once in a sharing session (yes, I failed). It was really tough to convince others when introducing a stuff/an idea was totally new. But, "Do it Anyway" because debating makes problems clear.

## New MacBook

This was something very normal but I think it's worth the money for tackling a new experience on a new operating system (macOS). I really loved it!

## Facing challenges in finding a new company

I had worked at my old company (Axon Active Vietnam) for more than 4 years. It was not too long but I felt that it was the time for me to move out of my "safe zone". I had spent much time for interviewing to select a company for my new journey. Sadly, I had failed in a lot of places, from Outsourcing to Product to Startup companies. It was really a frustrated decision but eventually, I made a resignation when I didn't have a new offer. And, even my manager who also suggested a raise to keep me on my team. I appreciated that.

Fortunately, I had received several offers (exactly 3) at the end days before I left my old company. The following was my log: (Company | Applied position | Interview Notes)
1. NVG | Senior Web Java Developer | Various questions about frameworks are being used.
2. LenderRate | Developer | Algorithms (level: hard, difficult).
3. ContentNet | Senior Developer | Deeply technical questions about Java core, design patterns and how to approach a technology.
4. Absolute Vietnam | Developer | Deeply technical questions about Java core (but, it's my strong points).
5. Innotech | Full-stack developer | Behavior questions (quickly, only <30 minutes).
6. FPT | Developer onsite longterm in Singapore | Specific frameworks (Restful API, NodeJS, Microservices).
7. Adnovum | Professional Developer | How you understand your most favorite projects and used technologies; algorithms (level: easy/medium).
8. Freelancer with my beloved team | So, I passed it without conditions (Haha).
9. Politely declined to interview at Zalora, SAI GON BPO.

## Winning my first project with my freelance team

With a strong spirit of a startup, my team focused on trying to make our first project super succeed by providing a good quality and fast-building application. It was not only collaborating well with customers but consulting them to have a "better" application.

The following were key values of my team:
- Having the same vision: sharing a "can do" attitude. We organized some practical sessions each sprint such as knowledge sharing, code reviewing, and retrospective.
- Focus: reflection and adaption on whole sprint goal, not individual tasks status.
- Being agile: being flexible/effective at work rather than following strictly a process.

My desk at CirCO CoWorking Space

Happy New Year! 2018.

1. It's cool is that I also applied to LenderRate back at the time when I was looking for a new job after leaving Axon Active. Can't deny that their exercise was a bit tricky. My "homework" is a task to deal with 2D nested array rotation algorithm. My implementation back then was accepted as clean and correct way but they demanded a far better solution, agh !

2. Holy crap! but, it was cool. Algorithms can be called as "Chi" in Kung Fu!

### AngularJS - Build a custom validation directive for using multiple emails in textarea

AngularJS already supports the built-in validation with text input with type email. Something simple likes the following:
<input name="input" ng-model="email.text" required="" type="email" /> <span class="error" ng-show="myForm.input.$error.email"> Not valid email!</span> However, I used a text area and I wanted to enter some email addresses that's saparated by a comma (,). I had a short research and it looked like AngualarJS has not supported this functionality so far. Therefore, I needed to build a custom directive that I could add my own validation functions. My validation was done only on client side, so I used the$validators object.

Note that, there is the $asyncValidators object which handles asynchronous validation, such as making an$http request to the backend.

This is just my implementation on my project. In order to understand that, I supposed you already had experiences with Angular…

### Creating a Chatbot with RiveScript in Java

Motivation"Artificial Intelligence (AI) is considered a major innovation that could disrupt many things. Some people even compare it to the Internet. A large investor firm predicted that some AI startups could become the next Apple, Google or Amazon within five years"
- Prof. John Vu, Carnegie Mellon University.

Using chatbots to support our daily tasks is super useful and interesting. In fact, "Jenkins CI, Jira Cloud, and Bitbucket" have been becoming must-have apps in Slack of my team these days.

There are some existing approaches for chatbots including pattern matching, algorithms, and neutral networks. RiveScript is a scripting language using "pattern matching" as a simple and powerful approach for building up a Chabot.
Architecture Actually, it was flexible to choose a programming language for the used Rivescript interpreter like Java, Go, Javascript, Python, and Perl. I went with Java.

Used Technologies and ToolsOracle JDK 1.8.0_151Apache Maven 3.5…

### Styling Sort Icons Using Font Awesome for Primefaces' Data Table

So far, Primefaces has used image sprites for displaying the sort icons. This leads to a problem if we want to make a different style for these icons; for example, I would make the icon "arrow up" more blurry at the first time the table loading because I want to highlight the icon "arrow down". I found a way that I can replace these icons with Font Awesome icons.

We will use "CSS Pseudo-classes" to achieve it. The hardest thing here is that we should handle displaying icons in different cases. There is a case both "arrow up" and "arrow down" showing and other case is only one of these icons is shown.

.ui-sortable-column-icon.ui-icon.ui-icon-carat-2-n-s { background-image: none; margin-left: 5px; font-size: 1.1666em; position: relative; } .ui-sortable-column-icon.ui-icon.ui-icon-carat-2-n-s:not(.ui-icon-triangle-1-s)::before { content: "\f106"; font-family: "FontAwesome"; position: absolut…

### Math fundamentals and Katex

It was really tough for me to understand many articles about data science due to the requirements of understanding mathematics (especially linear algebra). I’ve started to gain some basic knowledges about Math by reading a book first.The great tool Typora and stackedit with supporting Katex syntax simply helps me to display Math-related symbols.Let’s start!The fundamental ideas of mathematics: “doing math” with numbers and functions. Linear algebra: “doing math” with vectors and linear transformations.1. Solving equationsSolving equations means finding the value of the unknown in the equation. To find the solution, we must break the problem down into simpler steps. E.g:x2−4=45x2−4+4=45+4x2=49x=49∣x∣=7x=7 or x=−7\begin{aligned} x^2 - 4 &= 45\\ x^2 - 4 + 4 &= 45 + 4\\ x^2 &= 49\\ \sqrt{x}&=\sqrt{49}\\ |x| &= 7\\ x=7 &\text{ or } x=-7 \end{aligned}x2−4x2−4+4x2x​∣x∣x=7​=45=45+4=49=49​=7 or x=−7​2. NumbersDefinitions
Mathematicians like to classify the d

### Applying pipeline “tensorflow_embedding” of Rasa NLU

According to this nice article, there was a new pipeline released using a different approach from the standard one (spacy_sklearn). I wanted to give it a try to see whether it can help with improving bot’s accuracy.

After applying done, I gave an evaluation of “tensorflow_embedding”. It seemed to work better a bit. For example, I defined intents “greet” and “goodbye” with some following messages in my training data.
## intent:greet- Hey! How are you? - Hi! How can I help you? - Good to see you! - Nice to see you! - Hi - Hello - Hi there ## intent:goodbye- Bye - Bye Bye - See you later - Take care - Peace In order to play around with Rasa NLU, I created a project here. You can have a look at this change from this pull request. Yay!

When I entered message “hi bot”, then bot with “tensorflow_embedding” could detect intent “greet” with better confidence scores rather than bot with “spacy_sklearn”. The following are responses after executing curl -X POST localhost:5000/parse -d '{&qu…