Weekly Digest #39

Weekly Dev Blog

2 min readAug 23, 2021

Articles

Best practices for dependency management

Version pinning
Signature and has verification
Lockfiles and compiled dependencies
Mixing private and public dependencies (be care of the dependency confusion attack)
Removing unused dependencies
Vulnerability scanning

Surviving guide for a tech startup aka How to properly bootstrap your startup — Part 2

every line of code is a liability: you need to maintain it

Focus on your core values
To mobile or not
To SPA (Single page app) or not
Backend/API
Database
Hosting

Jeff Bezos says work-life balance is a ‘debilitating phrase.’ He wants Amazon workers to view their careers and lives as a ‘circle.’

“It actually is a circle,” Bezos said. “It’s not a balance.”

Tutorials

Modelling mutual friendship

Two-row model:

| user1_id | user2_id |
|---------------------|
|        3 |        5 |
|        5 |        3 |
-----------------------

Deleting friendship: a two-part DELETE command is needed;
Getting the list of friends: straightforward query;
Are they friends?: straightforward query;
Storage requirements: data size is twice as large;
Potential invariant violations: only one of two rows is present;

Single-row model:

CREATE TABLE mutual_friendship (
  user1_id INTEGER NOT NULL,
  user2_id INTEGER NOT NULL,
  PRIMARY KEY (user1_id, user2_id)
);| user1_id | user2_id |
|---------------------|
|        3 |        5 |

Deleting friendship: pre-processing is needed before DELETE;
Getting the list of friends: two-part query is needed;
Are they friends?: pre-processing (or two-part query) is needed;
Storage requirements: optimal data size, but an additional index would be needed;
Potential invariant violations: two symmetric rows; wrong order of IDs.