Sharing some random tidbits I learned throughout the week.

Week 2 at Shopify. This week was RnD onboarding and we had workshops and code labs to work on throughout the week as well as talks from developers from different teams.

  • Shipit was created and is used by Shopify to allow every developer at Shopify to deploy their changes to production with the click of a button.
    • Also allows easy rollbacks and/or reverting capabilities.
  • Fixtures are sample data that can be used to populate test databases.
    • Written in YAML format in the test/fixtures directory.
  • A Datacentre Failover is making a switch to another datacentre.
  • nginx is a web server with a focus on high concurrency, performance and low memory usage.
    • Can be used as a load balancer: A reverse proxy to distribute traffic across application servers.
    • Has 1 master process and multiple worker processes.
      • The master reads and evaluates the nginx.conf file and manages the worker processes which each process requests.
  • BEM stands for Blocks, Elements, Modifiers.
    • Methodology for naming css classes in large projects providing modularity, reusability and structure.
  • Turbograft is a modified version of Turbolinks allowing partial page refreshes.
    • Works by intercepting requests and fetching new body via Ajax whenever possible.
    • I guess this is what Turbolinks 3.0 will be like.
  • git push +branchname will force push only to one branch.
    • -f applies to all refs that are being pushed.
  • Splunk provides a web interface that allows searching through big data.
    • Contains information like application logs, message queues, database transactions, etc…
  • Phabricator is a suite of open source web applications for software development.
    • One of them is called Differential and has some neat features like incremental diffs and seeing what code reviews you need to do.
  • top displays a sorted list of system processes.
    • ps aux provides a snapshot showing processes for all users, displaying in a user-oriented fromat, as well as processes without a tty.
      • tty is a terminal.
  • script creates a typescript of everything printed on your terminal.
    • If argument file is given, save to a file.
  • ctags is a tool that will go through your code, indexing objects in a tags file.
    • With vim, you can highlight a function call and use <Ctrl-]> to jump to the definition.
    • Can also use :CtrlPTag to search for tags using ctrlp.
  • Interest Rates are determined by the central bank. Government economic observers create a policy to ensure stable prices and liquidity for the country.
    • Retail banks usually are the first to expose money to the economy. By adjusting the interest rates on the money the government lends to or borrows from the retail banks, the central bank can regulate the supply of money to individuals and companies.
    • To decrease the money supply, the government will increase the interest rate, making it attractive to deposit funds to gain more interest and reducing borrowing from the central bank.
    • On the other hand, to increase the money supply, the government will decrease the interest rate. This makes it attractive to borrow money with low interest rates.
      • Becoming a problem in Canada: Interest rates are so low so people are buying houses and cars. Demand is high, so there is a lot of inflation.
  • A bond is a debt investment issued by governments and corporations for the purpose of financing.
    • The Face Value is the amount the investor purchases the bond for.
    • The Coupon is the bond’s interest rate.
      • The higher the coupon, the riskier it is there is a greater chance for the issuer to default the bond.
      • Interest Rate Risk is the risk that an investment’s value will decrease if the interest rate rises.
        • The bond value and interest rate are inversely proportional.
    • The Maturity Date is the date the bond issuer repays the loan to the investor.
    • Can sell bonds before they mature.
  • A stock is a type of security that signifies ownership in a corporation.
    • Ownership of a portion of a corporation’s assets and earnings.
    • A dividend is a cash distribution by a corporation to its shareholders.
      • A company that is growing rapidly probably won’t pay dividends because it wants to invest as much as possible into further growth.
      • A company that things it is better to reinvest their earnings also won’t pay dividends.
      • Investors like steady income from dividends so offering them will make their stock more appealing.
        • Greater demand for stock increases its price.
  • A mutual fund is a pool of stocks, bonds or other securities.
    • Investing in a mutual fund is purchasing units of a professionally managed portfolio.
    • There are management fees but good for investors that don’t have the time to manage a portfolio.
    • Priced once a day after the market closes.
  • You can short a stock when you think a stock will go down in price.
    • Borrow shares of a stock and immediately sell them.
    • You must return those stocks at some point so if you purchase them back when the price goes down, you make money on the difference.
      • If you purchase them back when the price goes up, you lose money.
  • ETFs are Exchange Traded Funds
    • Similarly to a mutual fund, ETFs generally hold a portfolio of stocks, bonds or commodities.
    • ETF trades on the stock exchange and prices are updated throughout the day
    • Can short an ETF in the same way as a stock.
  • There are 2 types of orders to buy stock
    • Market Order buys or sell a stock at the best price available at the time the order is placed.
      • Quick to fill order, guaranteed execution.
    • Limit Order buys or sell a stock at a set price.
      • Control over price, can take longer to fill or might even expire.
  • A stock that is on different exchanges is called interlisted.
  • The major stock exchanges in Canada and the US are:
    • NYSE: New York Stock Exchange
    • NASDAQ: National Association of Securities Dealers Automated Quotations
    • TSX: Toronto Stock Exchange
  • Vim
    • CTRL-] and CTRL-o to navigate the vim help links.
    • CTRL-e and CTRL-y to move screen up and down without moving cursor.
    • u and CTRL-r provide undo and redo capabilities.
    • zz, zt, zb moves screen to be centered at the middle, top and bottom respectively, keeping your cursor on the current line.
    • Using Vundle as my plugin manager
      • Nerdtree to visualize my file structure.
      • ctrlp as my file finder.
      • syntastic for syntax checking.
      • commentary to quickly comment lines.
      • endwise for adding end structures for Ruby.
      • emmet for html expansion.
      • IndentWise for motions based on indent depths.
        • Need to find better keybindings for these. Seems useful but default bindings are far from the home row.