System Design

Background In my previous role, while working in the Insurance domain, we provided a mobile app to all customers who bought cyber insurance. This had some cool value added services that helped small enterprises check if their employees’ knowledge of cyber security is good enough to protect the organisation from being compromised. Thus we implemented a one-click phishing campaign solution, which enabled users to click a button and initiate a phishing campaign for the organisation. This was a really fun thing to work on. This was when I invested some time looking into how email really worked. I even wrote most of this post at the time. However, there are many such draft posts that I haven’t shared yet. Because that’s how life happens, constant interruptions with small moments of peace and I didn’t deprive myself of sleep to publish blog posts either. ...

Most good organisations expect their engineering hires to have gone through a system design interview. For a vast majority of people this might sound like a weird thing to do as most people don’t individually design large scale systems. So expecting someone to design a highly scalable and available system in less than 60 minutes is a daunting task. We must also consider the fact that not everyone gets to work in organisations that build large scale distributed systems. I think the time when I worked in FactSet was when I dealt with extremely large volumes of data and we focussed on the performance of queries from the database to sub 5 ms in order to ensure that even with latency, users would be able to see their graphs plotted in a second or so. Most applications wouldn’t really care about performance at that level because for their line business it probably doesn’t matter that much. ...

I was recently helping my friend with some preparation for a system design interview and as we discussed solutions, the terms Proxy server and reverse proxy came up in our discussions. I really struggled to give a simple explanation of the terms during our discussion. I just knew what one did. I did not even know that load balancers were generally reverse proxies. This is where knowledge of a natural language could be helpful. So I thought I would try and compile a simple description of both here and go look at the definition of Proxy from the dictionary. ...