Partnering with The Codero for complete digital payment gateway solutions

We have some great news to share with all of you. As you know we are continuously working to improve our solutions and service offering for our customers that we promised. Our entire journey depends on how we serve for our customers to develop their business rapidly with consistent improvement with our services. Today I am going to announce you a very exciting news.



Preview Technologies Limited has signed a MoU with The Codero Limited. The Codero Limited has a set of digital payment gateway solutions and specially one of their base payment gateway solutions “EasyPayWay” is now available for all of our new and existing customers who was just waiting to integrate digital payment gateway with their e-commerce website and get payment from mostly all kinds of payment system like bKash, Rocket, Credit/Debit Cards and Online Banking. This partnership is a great opportunity for Preview Technologies Limited to develop more easy, efficient and customized payment gateway solutions. Here is a solution snapshots I can’t wait to tell you.

Faster Merchant ID Create & Approval Process
All of our new and existing customer can now apply for getting a merchant account to get payment from their clients with debit/credit card, online banking and other popular payment providers.
This usually takes longer period of time to get merchant approval with lots of paperwork. But from now on, Preview Technologies Limited can process all merchant application with our partner The Codero Limited more quickly and efficiently.

Lowest Transaction Fees
We are still working to get it fixed and we will announce the transactions fees and registration pricing later but due to this partnership agreement we can now guarantee the lowest transaction and processing fees for our customers.

All Bangladeshi Popular Payment Method Supported
EasyPayWay, a solutions provided by The Codero Limited has a wide range of popular payment methods including bKash, Rocket, QCash, MCash, DBBL Nexus, Visa, MasterCard, JCB, City Bank, Payza, IFIC Mobile Banking, Discover, FastCash, etc.


Dedicated Dashboard With Extended Reporting
EasyPayWay will provide a dedicated dashboard to all of our customers where you can explore all kinds of payment and transaction related activity including, managing transaction, refund processing, withdraw request to bank, etc.

Extensive API Integration & Customization
EasyPayWay will provide a wide range of integration and customization features such as plugins, libraries, SDKs for all of our customers for better integration with existing system that we develop. Though, Preview Technologies Limited will help all of it’s customers to integrate payment gateway with their system that you shouldn’t worry about.

So ultimately, I couldn’t wait to share this extremely exciting news with you. On behalf of Preview Technologies Limited I can ensure a great flexible, efficient, reliable payment gateway solutions for all of our new and existing customers. Also besides expressing this news with all of you, I want to personally thanks to Mr. Riad and Mr. Rana from The Codero Limited team to make this happen and on behalf of our entire Preview Technologies family we hope for a greater future for both of our business in every way we can perform together.


Opening business in USA from Bangladesh

Regularly people asked about to open a business in USA from Bangladesh as a Bangladeshi. They have their different reasons. Someone want to get a business verified paypal account, someone want to run a dropshipping business from Bangladesh and want to take payment online, someone want to run some service to foreign people and someone want to gain more trust by registering a company in USA. Even sometimes people love to have a LLC or INC legal business name in United States of America. People come to us to get various types of IT service they run and want to run inside Bangladesh or outside Bangladesh, then at a step they ask if there is any opportunity to register a legal business entity in US.

We are operating our US operations under Preview Technologies LLC, a Delaware based corporation


Honestly and surely in most cases, YES you can register a LLC or INC company in US from Bangladesh as a Bangladeshi. You don’t need to go to USA or don’t need to be an american citizen. Legally it’s possible in United States to open a business by any foreign nationals. To register a company in USA, you have to go through some facts. Most importantly you have to remember that opening a business in US will not help you to live or go to US or obtaining a Visa, if you wonder. So let’s check it out about what types of things you need to know and check to open a business in US from Bangladesh as a Bangladeshi.

A. Study on the web
You will find plenty of article online about to get the ideas and checklists to start a business in US without going there. You can read the following articles that may help –
– Search Google with “Register a company in US by foreigner

B. Choose a name
You need to choose a name for your business. You can search a unique name from and get an unique name

C. Find state where your company will be registered
In US, every state has different law. You have to decide where you want to be legally registered. I prefer Delaware because of their flexible corporate law. Most people prefer Delaware to register their company. Our business “Preview Technologies LLC” is also registered in Delaware state.

D. Find a legal consultant individual or a company
There is a catch on this point. If you are not in the United States, then to open a company you must have to assign a registered agent from inside US. So to find that registered agent, there are lots of law firm across US who will provide you that service and they will work with you closely to register a business there.
They will do everything for you. I can provide some law firm here who provide all service to register your company in US from Bangladesh. They have package services.

Take their package solutions that will include company registration, virtual office address, virtual mailbox to receive letters & correspondents for your business, EIN registration. Most of them will provide all of them as a package

That’s it. When you will work with those law firm, you need to chose their packages. You can contact with them, call them, discuss about what they will do from A to Z. Pay their fees and you will get your registered LLC or INC company in US within couple hours to days (2-3 business days)

And when you will get your EIN (employer identification number), you can be able to register for paypal business account.

Preview Technologies Limited is a Bangladeshi registered private limited company and it’s running it’s US operation under Preview Technologies LLC, a Delaware based registered business entity. If you need any further advise regarding this matter, please write me at or write a comment in this post. I will be happy to assist with proper guidance.

Buy Google Stadia from Bangladesh

Buy Google Stadia from Bangladesh - Pre-order only

Be the first in Bangladesh as a Google Stadia UserPlay the high resolution game right from your Google chrome browser. No need to buy high configuration computer anymore. Google Stadia would be the next generation gaming platform. Stadia is a cloud gaming service operated by multinational technology company Google. According to Google, it is capable of streaming video games in 4K resolution at 60 frames per second with support for high-dynamic-range, to players via the company’s numerous data centers across the globe, if they are using a sufficiently high-quality Internet connection. It will be accessible through the company’s Google Chrome web browser. So be the first to buy Google Stadia from Bangladesh.

Google announces Stadia, a cloud-based gaming platform

According to Google, Stadia will remove the hardware limitations of PCs for the gamer and game developers can consume nearly unlimited resources to develop next generation games. It would be the “Netflix” of “Next generation gaming”

Google’s Stadia Announcement at GDC 2019 in Under 14 Minutes

Release date of Google Stadia in Bangladesh

The release date of Google Stadia has not been announced yet but Google says that in 2019 anytime soon it will be released. June can be a great time to release the Google Stadia for people to buy but it will be made available only US, Canada, UK, Europe. Bangladesh is not in the list but you don’t need to be worried about that.

We are trying to facilitate for people to buy Google Stadia from Bangladesh via our store (our store is only available for exclusive members) When it will be released in US we will try to make it available in Bangladesh too within a week. Currently we are taking booking as pre-order. If you are a crazy gamer and want to get excited and want to be the first user of Google Stadia in Bangladesh, write an email to with your contact details so we can shortlisted you for the pre-booking.

Google Stadia vs. PS4 Pro vs Xbox One X

Google Stadia Price in Bangladesh

Google didn’t disclose the price and subscription fees yet. But at least we can speculate that the biggest competitor or Google Stadia is Sony’s PlayStation Now $19.99. We will announce the price when it will be available publicly in US market.

If you are interested in buying Google Stadia from Bangladesh, feel free to write an email to for pre-order and getting early access of our exclusive online store. You can contact via our Facebook page (@previewtechs).

Important coverage for Google Stadia

About Google Stadia

Get OAuth 2.0 access token using Retrofit 2.x

Retrofit is an awesome and easy to use library. You can use Retrofit for any Android or Java application which need to interact with our OAuth2.0 server to get access token.

You just need to build the retrofit properly to get it done. It doesn’t require any advance knowledge. Let’s see how it can be done easily.

To get the access token using Retrofit we need to do –

Add Retrofit in your project via Maven or Gradle. Complete installation guide can be found here.

Now let’s create the Retrofit builder. And before doing that we need to create a service interface.

import retrofit2.Call;
import retrofit2.http.Field;
import retrofit2.http.FormUrlEncoded;
import retrofit2.http.POST;

public interface AccessTokenServiceInterface {

    Call<TokenResponse> getToken(@Field("client_id") String client_id, @Field("client_secret") String client_secret, @Field("scope") String scope, @Field("grant_type") String grant_type);

And now the builder.

import retrofit2.Call;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;


public class Http {
    public static void main(String[] args) {
        Retrofit retrofit = new Retrofit.Builder()

        AccessTokenServiceInterface service = retrofit.create(AccessTokenServiceInterface.class);

        //grant types = client_credentials
        Call<TokenResponse> call = service.getToken("OAUTH CLIENT ID", "OAUTH CLIENT SECRET", "basic email", "client_credentials");
        try {
            Response<TokenResponse> response = call.execute();
        } catch (IOException e) {

And also we need to map the JSON response from our OAuth 2.0 server. So we need a model to map that. Let’s create model class


public class TokenResponse {

    private String tokenType;
    private Integer expiresIn;
    private String accessToken;

    public String getTokenType() {
        return tokenType;

    public void setTokenType(String tokenType) {
        this.tokenType = tokenType;

    public Integer getExpiresIn() {
        return expiresIn;

    public void setExpiresIn(Integer expiresIn) {
        this.expiresIn = expiresIn;

    public String getAccessToken() {
        return accessToken;

    public void setAccessToken(String accessToken) {
        this.accessToken = accessToken;


Now run Http.main and you will get your access token.

That’s it. Now run the Http.main and you will get the access token easily. Download these scripts from our PreviewTechnologies/access-token-retrofit GitHub repository.

This article also available on our support portal.

cURL vs “file_get_contents()” in Google App Engine – Performance analysis

We all know that to do any kinds of external HTTP request from your PHP application (deployed in Google App Engine a.k.a GAE) we have three options basically. PHP native cURL extension, “cURL Lite” provided by Google and the native http:// and https:// PHP stream handlers.

cURL requires a valid billing profile and only you can enable it in your Google Cloud paid project. And that’s why Google’s custom cURL Lite actually use Google’s urlfetch service that you can use in your application free version.

But recent days, our engineering team was just wondering which can be little bit faster among cURL or cURL Lite or PHP native PHP HTTP handler, in this sense little bit faster meaning we also count even 50ms latency. That’s why I was running some test with a single script hosted on Google App Engine (PHP Standard Runtime environment). We had lots of PHP microservice apps hosted on Google App Engine and all services at a certain time needs to talk each other via HTTP external request. But sometimes, we were aware that latency is killing some communication.

So we just built 2 files basically in PHP. One is using cURL to post some foobar json data to an external URL ( and another one was using the native http:// and https:// PHP stream handlers. Let’s see what was our experimental scripts look like.


 * Using CURL

$data = array("foo" => "bar");
$data_string = json_encode($data);

$ch = curl_init('');
//$ch = curl_init('/post.php');
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'Content-Length: ' . strlen($data_string)

$result = curl_exec($ch);

 * php_http_stream.php
 * using cURL lite. It use google's urlfetch service

$url = '';
$data = array("foo" => "bar");
$data_string = json_encode($data);

$contentLength = strlen($data_string);

$headers = "accept: */*\r\n" .
    "Content-Type: application/json\r\n" .
    "Content-Length: $contentLength\r\n";

$context = [
    'http' => [
        'method' => 'POST',
        'header' => $headers,
        'content' => $data_string,
$context = stream_context_create($context);
$result = file_get_contents($url, false, $context);

And here is the trace report of those two call.

@0 ms
Name			RPCs	Total Duration (ms)
/curl_lite.php		1	450
/urlfetch.Fetch		1	333
Timestamp		xxxx-xx-xx (
Traced time 		333 ms
Untraced time 		117 ms

http/response/size	25
@0 ms
Name				RPCs	Total Duration (ms)
/curl.php			1	753
/remote_socket.Close		4	4
/remote_socket.Connect		10	157
/remote_socket.CreateSocket	4	10
/remote_socket.GetSocketOptions	1	1
/remote_socket.Poll		10	469
/remote_socket.Receive		2	2
/remote_socket.Send		2	2
/remote_socket.SetSocketOptions	1	1
Timestamp	2017-xx-xx (
Traced time 	646 ms
Untraced time 	107 ms

http/response/size		25

So what does it mean to you? It means a lot for me. Obviously cURL Lite is saving me couple milliseconds. And also I don’t need to be afraid of my “socket operation” quota that was used in cURL.

So in this, what should I say? file_get_contents() is more optimized? Of course, I am just talking how it’s performing for little external URL call with Google’s urlfetch service.

So if your application needs to interact with external service with less configuration and options, then I would prefer to use native PHP HTTP stream handler and make all external http call with file_get_contents() function. file_get_contents() use urlfetch service and you don’t need to enable cURL extension in your application.