What is a Nuclear Reactor?

A nuclear reactor generates electricity using the heat energy released from a nuclear fission reaction.

Can You Use Any Radioactive Material as Fuel?

No. This is a common misconception worth clearing up.

Radioactive and fissile are two very different things:

• Radioactive → The nucleus is unstable and decays, emitting radiation (alpha or beta particles)
• Fissile → The nucleus can be split by a neutron AND releases more neutrons to sustain a chain reaction

A reactor needs fissile material specifically — not just any radioactive material.

Suppose you had a raw video in very good quality (at 20Mbps bitrate). Obviously, you can’t stream this video to end-user where network bandwidth and speed is limited. So, you transcode this video at various bitrates 2Mbps, 1Mbps, …

Compared to original video, quality of this transcoded video will be less. We can see it with naked eye. At around 2-3Mbps, we won’t notice any difference but as bitrate starts going below 1Mbps, the difference is significantly noticeable.

If I have a digitally signed document, how do I verify if it is really signed ? How can I ensure that it is more than just a green tick photoshop ?

What if the amount of Rs. 10000 in document is tampered and made Rs. 100000 after I signed it ? What exactly happens when we digitally sign a document ? How secure is this system ?

Say I want to sign a document then two keys will be created.

We know the difference between syntactic and semantic search.

• Syntactic search is keyword based.
  Searching for Backend Engineer returns results like backend engineer or back-end engineer.

• Semantic search is meaning based.
  The same query can also return platform engineer, api developer, etc.

This difference exists because semantic search does not operate on raw text. Instead, both queries and documents are converted into vector embeddings — numerical representations that capture semantic meaning.

Setting up Google Workspace is different from setting up a personal Gmail account. Your domain is likely registered with a provider like GoDaddy or Namecheap, and email traffic must be routed to Google’s servers.

Example scenario:

• Domain abc.ai registered with GoDaddy
• Cloudflare as DNS provider (optional but recommended for easier setup)
• Goal: Create Google Workspace emails like pavan@abc.ai

Setup Steps

1. Configure DNS Provider (Optional - Cloudflare)

If using Cloudflare, update nameservers on GoDaddy domain settings to point to Cloudflare nameservers (typically elias.ns.cloudflare.com and megan.ns.cloudflare.com).

After reducing the RDS size, I was eager to watch the reduction in monthly bill. Earlier, RDS was costing around $11/day and now it should have cost me $3/day. But after few days of monitoring, it did not budge below $7/day. On splitting the cost by usage type, some storage cost had increased for RDS. On inspecting, I found that this was due to the snapshots that I had created before deleting the previous RDS instance. AWS provides free storage only upto the size of RDS (200GB in my case). But the previous snapshots were of 2TB. Hence, they were beyond free storage and were costing around $4/day. On deleting these snapshots, the RDS bill had come down to the expected value of $3/day.

So, when we found out the root cause for memory full the next step was to reduce the storage. After cleaning up the replication slot, WAL size had come down drastically. Now, 3GB storage was enough to hold current databases. But we were still paying for 2TB usage. So, we had to downscale RDS to reduce monthly bill.

Upscaling is easier in AWS and downscaling is equally tedious. RDS Storage are based on EBS volume which only expand and don’t allow shrinking. To upscale, it is just one click job (increase storage) but to downscale you need to create another database and switch traffic to that. In current setup, Blue-Green deployment provided by AWS seemed most convenient option (compared to DMS, or restore from storage).

On Sunday morning, I got lot of messages that production was down. Users are not able to login. Naturally, I went to Sentry to check if any alerts were raised. And there seemed to be a connection issue with Postgres database. I went to the db dashboard and it flagged that the RDS memory had exhausted. It had 1TB memory provisioned and that was exhausted. To resolve the problem immediately I provisioned more memory to it.

Redis used to be open source with BSD license. Berkeley Software Distribution (BSD) license gives full permission to use the software. It is like do whatever you want with this code, just don't blame us if it doesn't work.

Cloud providers used Redis and made lot of money over it, but nothing was shared back to Redis Ltd. Hence, they moved to a more restrictive licensing on March 2024. Their source code is still available but not for commercial hosting / service use. For commercial use you need to take their permission.

If you have a docker image of your service you can deploy it scalably using ECS. AWS handles all the orchestration for you. You need to provide a task definition and once deployment is run, ECS creates tasks (running containers) as per task definition. An ECS service ensures that desired number of tasks are always running.

For standard services you have container images publically available. But mostly if you are using ECS, you will be trying to create your own docker image that would run some server or anything. But then how does ECS know about your docker image ?