I work in a software engineering organization, how to improve my English communication skills (speaking and writing) in a short duration of time?

1. Find native English speakers and practice with them.

2. Listen to English Music.

3. Slow down while speaking to be understood.

4. Record yourself to know the weak and strong points to know what to work on.

5. Speak English at home and with friends.

6. Watch English movies and try not to read the translation.

7. Surf the internet and try to read online English magazines, articles and so on.

1. In my opinion, the most important is listening, I believe we have to learn a new language as same as children.
2. 1- Listening
3. 2- speak
4. 3- write.
5. listening and analyze the letters from native speakers is so important to know the hidden letters. Then speaking, most of us when we try to speak and communicate with others we get confused because of the vocabulary. do not be shy to use it. Then study the form grammar to know how to write well. There is a business writing classes try to enroll of one of them because writing is skill the we learn.
6.  
7. Good luck 

Go through English learning channels on youtube plus watching movies and listening to songs

hi  to Improve Your English Writing Skills in short time you need

1. Keep All of your Writing in One Place

2. Practice Writing in English Daily

3. Pick a Topic and WRITE!

4. Write More than One Draft

5. Use Online Resources to Correct your Grammar

6. Think outside the Box (or Lines)

7. Have a Friend Edit Your Writing

8. Find the Best Place for You to Write

And for speaking skills you need to :

1.  Listen to English Speaking Shows. Find an interesting TV show, radio show, or even podcast that you can listen to both at home and on the go. ...

2. Start A Blog. Use your hobbies, field of study or career path to help you learn English. ...

3. Use Ginger's English Personal Trainer. and good luck

I didn't mean to discourage but

They say in order to learn a language and have native fluency, you have to 

Change your mother tongue

Speaking-Watch hollywood movies with subtitle grab the sentence and use in your daily life,

Writing-Social Media is enough to practice and improve writing Skills,

Don't try too hard to improve try something smarter to improve:)  

I will say the answer of this question is hardworking. If we really like to improve our english skills we should consider day night the below main points. 

1 - Should regularly watch English speeches or videos. 

2 - Start writing speeches. 

3 -  Start communicating with English while speaking with any person. 

Communicate in English while you are with your friends and family members.

It has to be to improve the skill in English of two things:The first is the large number of listening and speaking in English.Second: MAKE daily practice, for example, the computer language of English / Mobile / language listen to the news and Altdt with the caster's level and thus improve in quick timeYou my thanks and greetings

Four skills activities

Reading

Writing

Speaking

Listing