What is technical debt? and how to handle it

Overview: Technical Debt generally refers to a buildup of deficiencies that makes changing code or optimizing systems difficult.  The key is to identify what in you organisation/program/project makes up technical debt.  

Technical Debt generally refers to poor or missing NFRs such as Performance, Security, Maintainability, Reliability, Scalability,  Testability, or Resiliency.  But it also can go further into future architecture, so if this part of our system is popular can we easily adjust and keep releasing features.  So as you can see, technical debt can be very wide and it's far better to focus a subset otherwise PO and PM's tend to scope everything under technical debt and wit gets nasty telling them about "additional technical debt".

I find the easier way to go about defining what is technical debt to avoid long discussions to to list out what cannot be considered technical debt.  This would be my minimum starting point:

1. Bugs (Functional defects);
2. Technical Skill Debt;
3. Process Defects (Lack of process or poor process, such as Configuration Management);
4. Feature Debt (Wrong or delayed features or missing functionality (recent favorite example is "how can a system not have customer off boarding it's obviously technical debt", this is feature debt, make sure stakeholders know or it falls into the old IT/Dev are weak and missed things description.); and
5. UI/UX Defects (Inconsistent or poor or changing user experience).

Another items is spaghetti code that falls under the NFR of code maintainability, with old systems you have to be pragmatic, if the product brings in $100k per year it's not a good idea to spend $120k a year making the code more readable but not improving the technology as a general rule.  On old systems, I try to keep code maintainability out of the technical debt,.  You should put it to another more detailed section, just don't lump everything especially when it is huge changes all under technical debt.  Dev teams loose focus and it causes problems don the line.  All too often, over exercised bundling debt pushed into technical debt results in "even more interest to pay later".

Azure Application Gateway Basics

Azure Application Gateway is a http traffic load balancer that allows me to manage my web traffic.  So based on urls, paths, the traffic can be pushed on accordingly.  It also provides for sticky sessions.  In my head I see Azure Application Gateway as a layer 7 HTTP Load Balancer and a Web Application Firewall (WAF).  There are 3 core concepts: Front-ends, rules and backends that are used to route traffic from the front-end to the back-ends.

Azure Load Balancer works at level 4 where Azure application gateway is for web traffic at layer 7 of the OSI model.

Azure Front Door is basically for world wide Application gateway functionality.

Checklist on the Application Gateway: 

• You should enable the WAF unless you already use another WAF like Imperva enterprise wide, do this under the "Web application firewall" option, setup OWASP rules.  
• Config session affinity, and HTTPS termination using the "HTTP settings".  
• "Listeners"  are what listens for incoming http requests.
• "Rules" bind the listeners to the backend pools.
• "Backend pools" are used to point traffic to the end points.  Also remember to setup "Health Probes", this allows the App pool to verify the backends are working.
•  Ensure you set the diagnostics logging to send logs to "Log Analytics" so you can examine the logs.

Features: 

1. SSL/TLS termination - Terminate SSL using certificate
2. Autoscaling - increase the size or instance count based on traffic requirements
3. Can be setup to be zone redundant
4. Static IP address that doesn't change
5. WAF and DDoS (pretty new 2022, applied using Azure DDoS Sentinel service) capabilities - The WAF allows you to apply OWASP rules and add additional custom rules.  Bot protection is also built in, rules need to be applied to get it to work.  
6. URL-based routing
7. Multiple domains/site hosting
8. Redirection
9. Sticky sessions/session affinity
10. HTTP/2 support
11. Custom error pages (so useful)
12. Rewrite headers and URL

References:

How an application gateway works | Microsoft Docs

WAF options

Personal Access Tokens (PAT)

Personal Access Token (PAT) are used a lot for automation in DevOps, once again need to lookup the informal on PATs.  I use Postman and I use PATs to automate connecting to Azure resources.

https://learn.microsoft.com/en-us/azure/devops/organizations/accounts/use-personal-access-tokens-to-authenticate?view=azure-devops&tabs=Windows

Store the PAT as it won't be retrievable again.