Author Archives: Neil Rubens

About Neil Rubens

see http://ActiveIntelligence.org

Technology Problem Fit / Technology Market Fit

Product Market Fit (pmf) has rightfully became a popular approach for many startups.  However, in some cases when you already have deep technical knowledge (deep tech); changing underlying technology of your product is not an option since it would erode … Continue reading

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AWS API Gateway – Lambda CORS troubles: Access to fetch at execute-api from origin cloudfront.net has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. If an opaque response serves your needs, set the request’s mode to ‘no-cors’ to fetch the resource with CORS disabled.

Problem Access to fetch at execute-api from origin cloudfront.net has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource. If an opaque response serves your needs, set the request’s mode to ‘no-cors’ to fetch the … Continue reading

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Azure Functions: System.InvalidOperationException: ‘The host has not yet started.’

Problem was getting the following exception System.InvalidOperationException: ‘The host has not yet started.’ System.InvalidOperationException HResult=0x80131509 Message=The host has not yet started. Source=Microsoft.Azure.WebJobs.Host StackTrace: at Microsoft.Azure.WebJobs.JobHost.StopAsync() in C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\JobHost.cs:line 121 at Microsoft.Azure.WebJobs.Hosting.JobHostService.StopAsync(CancellationToken cancellationToken) in C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Hosting\JobHostService.cs:line 32 at Microsoft.Extensions.Hosting.Internal.Host.<StopAsync>d__10.MoveNext()   Solution Solution was … Continue reading

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Microsoft.Azure.WebJobs.Host: Error indexing method ‘HubFunction.Run’. Microsoft.Azure.WebJobs.ServiceBus: Value cannot be null.

Got the following errors when trying out Azure’s Event Hub trigger for Azure Functions Warning: Cannot find value named ‘Endpoint=sb://DDDD’ in local.settings.json that matches ‘connection’ property set on ‘eventHubTrigger’ in You can run ‘func azure functionapp fetch-app-settings <functionAppName>’ or specify … Continue reading

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Evaluating Startup

There are many articles about how to evaluate startups.  I wanted to add my 2c. An approach that I’ve recently stumbled upon; when evaluating startup is to trying to find a great aspect about it (or imagine how it could … Continue reading

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Adding Typescript to AWS Amplify React

Here are a few small changes that you need for enabling support for typescript in AWS Amplify React   in tsconfig.json change target to: “target”: “es6”,   Then install necessary packages (here are the basic ones): npm install typescript –save … Continue reading

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2018 Best Laptop for Startup’s Technical Founder

I have an analytical mindset; which is a blessing and a curse.  Am having great time working on my startup sectormap.net but then spend way too much time on trying to decide what to buy (laptop in this case). Spoiler: clear … Continue reading

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Startup: registering / running corporation in Hong Kong (Banking, etc.)

Summary free, simple & fast bank account opening with Neat (don’t need to visit HK) $200 UD (setup), and $1,200 USD for annual running costs; by using Kams  (accounting, audit, office services; in simple case; government fees are excluded) Details As a startup, … Continue reading

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Play Json with Scala Trait

To be able to use trait with Play Json; you need to provide un/apply methods for the trait; and define a case class that could be instantiated. (there might be a better approach)   import play.api.libs.json.Json trait PaginatedTrait { def … Continue reading

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Using Lambda with multiple handlers in AWS Step Functions

Problem Using lambda function with multiple handlers is non-trivial in AWS Step Functions Solution Lambda is great; however one of the limitations is that only a single handler function is used.  Maintaining multiple lambda functions gets cumbersome quickly. One common … Continue reading

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